# System.Windows.Forms

``` diff
 namespace System.Windows.Forms {
-    public class AccessibleObject : StandardOleMarshalObject, IAccessible, IEnumVARIANT.Interface, Interop.UiaCore.IAccessibleEx, Interop.UiaCore.IExpandCollapseProvider, Interop.UiaCore.IGridItemProvider, Interop.UiaCore.IGridProvider, Interop.UiaCore.IInvokeProvider, Interop.UiaCore.ILegacyIAccessibleProvider, Interop.UiaCore.IMultipleViewProvider, Interop.UiaCore.IRangeValueProvider, Interop.UiaCore.IRawElementProviderFragment, Interop.UiaCore.IRawElementProviderFragmentRoot, Interop.UiaCore.IRawElementProviderHwndOverride, Interop.UiaCore.IRawElementProviderSimple, Interop.UiaCore.IScrollItemProvider, Interop.UiaCore.ISelectionItemProvider, Interop.UiaCore.ISelectionProvider, Interop.UiaCore.ITableItemProvider, Interop.UiaCore.ITableProvider, Interop.UiaCore.ITextProvider, Interop.UiaCore.ITextProvider2, Interop.UiaCore.IToggleProvider, Interop.UiaCore.IValueProvider, IOleWindow.Interface, IReflect, IServiceProvider.Interface {
+    public class AccessibleObject : StandardOleMarshalObject, IAccessible, IAccessible.Interface, IAccessibleEx.Interface, IDispatch.Interface, IDispatchEx.Interface, IEnumVARIANT.Interface, IExpandCollapseProvider.Interface, IGridItemProvider.Interface, IGridProvider.Interface, IInvokeProvider.Interface, ILegacyIAccessibleProvider.Interface, IManagedWrapper, IManagedWrapper<IDispatch, IDispatchEx, IAccessible, IAccessibleEx, IServiceProvider, IRawElementProviderSimple, IRawElementProviderFragment, IRawElementProviderFragmentRoot, IInvokeProvider, IValueProvider, IRangeValueProvider, IExpandCollapseProvider, IToggleProvider, ITableProvider, ITableItemProvider, IGridProvider, IGridItemProvider, IEnumVARIANT, IOleWindow, ILegacyIAccessibleProvider, ISelectionProvider, ISelectionItemProvider, IRawElementProviderHwndOverride, IScrollItemProvider, IMultipleViewProvider, ITextProvider, ITextProvider2>, IMultipleViewProvider.Interface, IOleWindow.Interface, IRangeValueProvider.Interface, IRawElementProviderFragment.Interface, IRawElementProviderFragmentRoot.Interface, IRawElementProviderHwndOverride.Interface, IRawElementProviderSimple.Interface, IReflect, IScrollItemProvider.Interface, ISelectionItemProvider.Interface, ISelectionProvider.Interface, IServiceProvider.Interface, ITableItemProvider.Interface, ITableProvider.Interface, ITextProvider.Interface, ITextProvider2.Interface, IToggleProvider.Interface, IValueProvider.Interface {
-        int IAccessible.accChildCount { get; }
+        int Accessibility.IAccessible.accChildCount { get; }
-        object IAccessible.accFocus { get; }
+        object? Accessibility.IAccessible.accFocus { get; }
-        object IAccessible.accParent { get; }
+        object? Accessibility.IAccessible.accParent { get; }
-        object IAccessible.accSelection { get; }
+        object? Accessibility.IAccessible.accSelection { get; }
-        public virtual string DefaultAction { get; }
+        public virtual string? DefaultAction { get; }
-        public virtual string Description { get; }
+        public virtual string? Description { get; }
-        public virtual string Help { get; }
+        public virtual string? Help { get; }
-        public virtual string KeyboardShortcut { get; }
+        public virtual string? KeyboardShortcut { get; }
-        public virtual string Name { get; set; }
+        public virtual string? Name { get; set; }
-        public virtual AccessibleObject Parent { get; }
+        public virtual AccessibleObject? Parent { get; }
-        Type IReflect.UnderlyingSystemType { get; }
+        Type System.Reflection.IReflect.UnderlyingSystemType { get; }
-        public virtual string Value { get; set; }
+        public virtual string? Value { get; set; }
-        void IAccessible.accDoDefaultAction(object childID);
+        void Accessibility.IAccessible.accDoDefaultAction(object childID);
-        object IAccessible.accHitTest(int xLeft, int yTop);
+        object? Accessibility.IAccessible.accHitTest(int xLeft, int yTop);
-        void IAccessible.accLocation(out int pxLeft, out int pyTop, out int pcxWidth, out int pcyHeight, object childID);
+        void Accessibility.IAccessible.accLocation(out int pxLeft, out int pyTop, out int pcxWidth, out int pcyHeight, object childID);
-        object? IAccessible.accNavigate(int navDir, object childID);
+        object? Accessibility.IAccessible.accNavigate(int navDir, object childID);
-        void IAccessible.accSelect(int flagsSelect, object childID);
+        void Accessibility.IAccessible.accSelect(int flagsSelect, object childID);
-        object? IAccessible.get_accChild(object childID);
+        object? Accessibility.IAccessible.get_accChild(object childID);
-        string? IAccessible.get_accDefaultAction(object childID);
+        string? Accessibility.IAccessible.get_accDefaultAction(object childID);
-        string? IAccessible.get_accDescription(object childID);
+        string? Accessibility.IAccessible.get_accDescription(object childID);
-        string? IAccessible.get_accHelp(object childID);
+        string? Accessibility.IAccessible.get_accHelp(object childID);
-        int IAccessible.get_accHelpTopic(out string? pszHelpFile, object childID);
+        int Accessibility.IAccessible.get_accHelpTopic(out string? pszHelpFile, object childID);
-        string? IAccessible.get_accKeyboardShortcut(object childID);
+        string? Accessibility.IAccessible.get_accKeyboardShortcut(object childID);
-        string? IAccessible.get_accName(object childID);
+        string? Accessibility.IAccessible.get_accName(object childID);
-        object? IAccessible.get_accRole(object childID);
+        object? Accessibility.IAccessible.get_accRole(object childID);
-        object? IAccessible.get_accState(object childID);
+        object? Accessibility.IAccessible.get_accState(object childID);
-        string? IAccessible.get_accValue(object childID);
+        string? Accessibility.IAccessible.get_accValue(object childID);
-        void IAccessible.set_accName(object childID, string newName);
+        void Accessibility.IAccessible.set_accName(object childID, string newName);
-        void IAccessible.set_accValue(object childID, string newValue);
+        void Accessibility.IAccessible.set_accValue(object childID, string newValue);
-        public virtual AccessibleObject GetChild(int index);
+        public virtual AccessibleObject? GetChild(int index);
-        public virtual AccessibleObject GetFocused();
+        public virtual AccessibleObject? GetFocused();
-        public virtual int GetHelpTopic(out string fileName);
+        public virtual int GetHelpTopic(out string? fileName);
-        public virtual AccessibleObject GetSelected();
+        public virtual AccessibleObject? GetSelected();
-        public virtual AccessibleObject HitTest(int x, int y);
+        public virtual AccessibleObject? HitTest(int x, int y);
-        public virtual AccessibleObject Navigate(AccessibleNavigation navdir);
+        public virtual AccessibleObject? Navigate(AccessibleNavigation navdir);
-        public bool RaiseAutomationNotification(AutomationNotificationKind notificationKind, AutomationNotificationProcessing notificationProcessing, string notificationText);
+        public bool RaiseAutomationNotification(AutomationNotificationKind notificationKind, AutomationNotificationProcessing notificationProcessing, string? notificationText);
-        FieldInfo? IReflect.GetField(string name, BindingFlags bindingAttr);
+        FieldInfo? System.Reflection.IReflect.GetField(string name, BindingFlags bindingAttr);
-        FieldInfo[] IReflect.GetFields(BindingFlags bindingAttr);
+        FieldInfo[] System.Reflection.IReflect.GetFields(BindingFlags bindingAttr);
-        MemberInfo[] IReflect.GetMember(string name, BindingFlags bindingAttr);
+        MemberInfo[] System.Reflection.IReflect.GetMember(string name, BindingFlags bindingAttr);
-        MemberInfo[] IReflect.GetMembers(BindingFlags bindingAttr);
+        MemberInfo[] System.Reflection.IReflect.GetMembers(BindingFlags bindingAttr);
-        MethodInfo? IReflect.GetMethod(string name, BindingFlags bindingAttr);
+        MethodInfo? System.Reflection.IReflect.GetMethod(string name, BindingFlags bindingAttr);
-        MethodInfo IReflect.GetMethod(string name, BindingFlags bindingAttr, Binder binder, Type[] types, ParameterModifier[] modifiers);
+        MethodInfo? System.Reflection.IReflect.GetMethod(string name, BindingFlags bindingAttr, Binder? binder, Type[] types, ParameterModifier[]? modifiers);
-        MethodInfo[] IReflect.GetMethods(BindingFlags bindingAttr);
+        MethodInfo[] System.Reflection.IReflect.GetMethods(BindingFlags bindingAttr);
-        PropertyInfo[] IReflect.GetProperties(BindingFlags bindingAttr);
+        PropertyInfo[] System.Reflection.IReflect.GetProperties(BindingFlags bindingAttr);
-        PropertyInfo? IReflect.GetProperty(string name, BindingFlags bindingAttr);
+        PropertyInfo? System.Reflection.IReflect.GetProperty(string name, BindingFlags bindingAttr);
-        PropertyInfo IReflect.GetProperty(string name, BindingFlags bindingAttr, Binder binder, Type returnType, Type[] types, ParameterModifier[] modifiers);
+        PropertyInfo? System.Reflection.IReflect.GetProperty(string name, BindingFlags bindingAttr, Binder? binder, Type? returnType, Type[] types, ParameterModifier[]? modifiers);
-        object IReflect.InvokeMember(string name, BindingFlags invokeAttr, Binder binder, object target, object[] args, ParameterModifier[] modifiers, CultureInfo culture, string[]? namedParameters);
+        object? System.Reflection.IReflect.InvokeMember(string name, BindingFlags invokeAttr, Binder? binder, object? target, object?[]? args, ParameterModifier[]? modifiers, CultureInfo? culture, string[]? namedParameters);
     }
     public class AutoCompleteStringCollection : ICollection, IEnumerable, IList {
-        public void AddRange(string[] value);
+        public void AddRange(params string[] value);
     }
     public abstract class AxHost : Control, ICustomTypeDescriptor, ISupportInitialize {
-        object ICustomTypeDescriptor.GetEditor(Type editorBaseType);
+        object? ICustomTypeDescriptor.GetEditor(Type editorBaseType);
-        EventDescriptorCollection ICustomTypeDescriptor.GetEvents(Attribute[] attributes);
+        EventDescriptorCollection ICustomTypeDescriptor.GetEvents(Attribute[]? attributes);
-        PropertyDescriptorCollection ICustomTypeDescriptor.GetProperties(Attribute[] attributes);
+        PropertyDescriptorCollection ICustomTypeDescriptor.GetProperties(Attribute[]? attributes);
     }
     public class BindingSource : Component, IBindingList, IBindingListView, ICancelAddNew, ICollection, ICurrencyManagerProvider, IEnumerable, IList, ISupportInitialize, ISupportInitializeNotification, ITypedList {
-        public BindingSource(object dataSource, string dataMember);
+        public BindingSource(object? dataSource, string dataMember);
-        bool System.ComponentModel.ISupportInitializeNotification.IsInitialized { get; }
+        bool ISupportInitializeNotification.IsInitialized { get; }
-        public virtual PropertyDescriptorCollection GetItemProperties(PropertyDescriptor[] listAccessors);
+        public virtual PropertyDescriptorCollection GetItemProperties(PropertyDescriptor[]? listAccessors);
-        public virtual string GetListName(PropertyDescriptor[] listAccessors);
+        public virtual string GetListName(PropertyDescriptor[]? listAccessors);
-        void System.ComponentModel.IBindingList.AddIndex(PropertyDescriptor property);
+        void IBindingList.AddIndex(PropertyDescriptor property);
-        void System.ComponentModel.IBindingList.RemoveIndex(PropertyDescriptor prop);
+        void IBindingList.RemoveIndex(PropertyDescriptor prop);
-        void System.ComponentModel.ICancelAddNew.CancelNew(int position);
+        void ICancelAddNew.CancelNew(int position);
-        void System.ComponentModel.ICancelAddNew.EndNew(int position);
+        void ICancelAddNew.EndNew(int position);
-        void System.ComponentModel.ISupportInitialize.BeginInit();
+        void ISupportInitialize.BeginInit();
-        void System.ComponentModel.ISupportInitialize.EndInit();
+        void ISupportInitialize.EndInit();
     }
     public class ComboBox : ListControl {
         public class ObjectCollection : ICollection, IComparer<ComboBox.ObjectCollection.Entry>, IEnumerable, IList {
-            public void AddRange(object[] items);
+            public void AddRange(params object[] items);
         }
     }
     public class Control : Component, IArrangedElement, IBindableComponent, IComponent, IDisposable, IDropTarget, IHandle<HWND>, IKeyboardToolTip, IOleControl.Interface, IOleInPlaceActiveObject.Interface, IOleInPlaceObject.Interface, IOleObject.Interface, IOleWindow.Interface, IPersist.Interface, IPersistPropertyBag.Interface, IPersistStorage.Interface, IPersistStreamInit.Interface, IQuickActivate.Interface, ISupportOleDropSource, ISynchronizeInvoke, IViewObject.Interface, IViewObject2.Interface, IWin32Window {
         public class ControlCollection : ArrangedElementCollection, ICloneable, ICollection, IEnumerable, IList {
-            public virtual void AddRange(Control[] controls);
+            public virtual void AddRange(params Control[] controls);
         }
     }
     public class ControlBindingsCollection : BindingsCollection {
-        public Control Control { get; }
+        public Control? Control { get; }
-        public Binding this[string propertyName] { get; }
+        public Binding? this[string propertyName] { get; }
-        public Binding Add(string propertyName, object dataSource, string dataMember);
+        public Binding Add(string propertyName, object dataSource, string? dataMember);
-        public Binding Add(string propertyName, object dataSource, string dataMember, bool formattingEnabled);
+        public Binding Add(string propertyName, object dataSource, string? dataMember, bool formattingEnabled);
-        public Binding Add(string propertyName, object dataSource, string dataMember, bool formattingEnabled, DataSourceUpdateMode updateMode);
+        public Binding Add(string propertyName, object dataSource, string? dataMember, bool formattingEnabled, DataSourceUpdateMode updateMode);
-        public Binding Add(string propertyName, object dataSource, string dataMember, bool formattingEnabled, DataSourceUpdateMode updateMode, object nullValue);
+        public Binding Add(string propertyName, object dataSource, string? dataMember, bool formattingEnabled, DataSourceUpdateMode updateMode, object? nullValue);
-        public Binding Add(string propertyName, object dataSource, string dataMember, bool formattingEnabled, DataSourceUpdateMode updateMode, object nullValue, string formatString);
+        public Binding Add(string propertyName, object dataSource, string? dataMember, bool formattingEnabled, DataSourceUpdateMode updateMode, object? nullValue, string formatString);
-        public Binding Add(string propertyName, object dataSource, string dataMember, bool formattingEnabled, DataSourceUpdateMode updateMode, object nullValue, string formatString, IFormatProvider formatInfo);
+        public Binding Add(string propertyName, object dataSource, string? dataMember, bool formattingEnabled, DataSourceUpdateMode updateMode, object? nullValue, string formatString, IFormatProvider? formatInfo);
     }
     public class CurrencyManager : BindingManagerBase {
-        protected internal override string GetListName(ArrayList listAccessors);
+        protected internal override string GetListName(ArrayList? listAccessors);
     }
     public class DataGridView : Control, ISupportInitialize {
-        public override Image BackgroundImage { get; set; }
+        public override Image? BackgroundImage { get; set; }
-        public DataGridViewCell CurrentCell { get; set; }
+        public DataGridViewCell? CurrentCell { get; set; }
-        public DataGridViewRow CurrentRow { get; }
+        public DataGridViewRow? CurrentRow { get; }
-        public object DataSource { get; set; }
+        public object? DataSource { get; set; }
-        public Control EditingControl { get; }
+        public Control? EditingControl { get; }
-        public DataGridViewCell FirstDisplayedCell { get; set; }
+        public DataGridViewCell? FirstDisplayedCell { get; set; }
-        public DataGridViewColumn SortedColumn { get; }
+        public DataGridViewColumn? SortedColumn { get; }
-        public Cursor UserSetCursor { get; }
+        public Cursor? UserSetCursor { get; }
-        public event EventHandler AllowUserToAddRowsChanged;
+        public event EventHandler? AllowUserToAddRowsChanged;
-        public event EventHandler AllowUserToDeleteRowsChanged;
+        public event EventHandler? AllowUserToDeleteRowsChanged;
-        public event EventHandler AllowUserToOrderColumnsChanged;
+        public event EventHandler? AllowUserToOrderColumnsChanged;
-        public event EventHandler AllowUserToResizeColumnsChanged;
+        public event EventHandler? AllowUserToResizeColumnsChanged;
-        public event EventHandler AllowUserToResizeRowsChanged;
+        public event EventHandler? AllowUserToResizeRowsChanged;
-        public event EventHandler AlternatingRowsDefaultCellStyleChanged;
+        public event EventHandler? AlternatingRowsDefaultCellStyleChanged;
-        public event EventHandler AutoGenerateColumnsChanged;
+        public event EventHandler? AutoGenerateColumnsChanged;
-        public event DataGridViewAutoSizeColumnModeEventHandler AutoSizeColumnModeChanged;
+        public event DataGridViewAutoSizeColumnModeEventHandler? AutoSizeColumnModeChanged;
-        public event DataGridViewAutoSizeColumnsModeEventHandler AutoSizeColumnsModeChanged;
+        public event DataGridViewAutoSizeColumnsModeEventHandler? AutoSizeColumnsModeChanged;
-        public event DataGridViewAutoSizeModeEventHandler AutoSizeRowsModeChanged;
+        public event DataGridViewAutoSizeModeEventHandler? AutoSizeRowsModeChanged;
-        public new event EventHandler BackColorChanged;
+        public new event EventHandler? BackColorChanged;
-        public event EventHandler BackgroundColorChanged;
+        public event EventHandler? BackgroundColorChanged;
-        public new event EventHandler BackgroundImageChanged;
+        public new event EventHandler? BackgroundImageChanged;
-        public new event EventHandler BackgroundImageLayoutChanged;
+        public new event EventHandler? BackgroundImageLayoutChanged;
-        public event EventHandler BorderStyleChanged;
+        public event EventHandler? BorderStyleChanged;
-        public event QuestionEventHandler CancelRowEdit;
+        public event QuestionEventHandler? CancelRowEdit;
-        public event DataGridViewCellCancelEventHandler CellBeginEdit;
+        public event DataGridViewCellCancelEventHandler? CellBeginEdit;
-        public event EventHandler CellBorderStyleChanged;
+        public event EventHandler? CellBorderStyleChanged;
-        public event DataGridViewCellEventHandler CellClick;
+        public event DataGridViewCellEventHandler? CellClick;
-        public event DataGridViewCellEventHandler CellContentClick;
+        public event DataGridViewCellEventHandler? CellContentClick;
-        public event DataGridViewCellEventHandler CellContentDoubleClick;
+        public event DataGridViewCellEventHandler? CellContentDoubleClick;
-        public event DataGridViewCellEventHandler CellContextMenuStripChanged;
+        public event DataGridViewCellEventHandler? CellContextMenuStripChanged;
-        public event DataGridViewCellContextMenuStripNeededEventHandler CellContextMenuStripNeeded;
+        public event DataGridViewCellContextMenuStripNeededEventHandler? CellContextMenuStripNeeded;
-        public event DataGridViewCellEventHandler CellDoubleClick;
+        public event DataGridViewCellEventHandler? CellDoubleClick;
-        public event DataGridViewCellEventHandler CellEndEdit;
+        public event DataGridViewCellEventHandler? CellEndEdit;
-        public event DataGridViewCellEventHandler CellEnter;
+        public event DataGridViewCellEventHandler? CellEnter;
-        public event DataGridViewCellEventHandler CellErrorTextChanged;
+        public event DataGridViewCellEventHandler? CellErrorTextChanged;
-        public event DataGridViewCellErrorTextNeededEventHandler CellErrorTextNeeded;
+        public event DataGridViewCellErrorTextNeededEventHandler? CellErrorTextNeeded;
-        public event DataGridViewCellFormattingEventHandler CellFormatting;
+        public event DataGridViewCellFormattingEventHandler? CellFormatting;
-        public event DataGridViewCellEventHandler CellLeave;
+        public event DataGridViewCellEventHandler? CellLeave;
-        public event DataGridViewCellMouseEventHandler CellMouseClick;
+        public event DataGridViewCellMouseEventHandler? CellMouseClick;
-        public event DataGridViewCellMouseEventHandler CellMouseDoubleClick;
+        public event DataGridViewCellMouseEventHandler? CellMouseDoubleClick;
-        public event DataGridViewCellMouseEventHandler CellMouseDown;
+        public event DataGridViewCellMouseEventHandler? CellMouseDown;
-        public event DataGridViewCellEventHandler CellMouseEnter;
+        public event DataGridViewCellEventHandler? CellMouseEnter;
-        public event DataGridViewCellEventHandler CellMouseLeave;
+        public event DataGridViewCellEventHandler? CellMouseLeave;
-        public event DataGridViewCellMouseEventHandler CellMouseMove;
+        public event DataGridViewCellMouseEventHandler? CellMouseMove;
-        public event DataGridViewCellMouseEventHandler CellMouseUp;
+        public event DataGridViewCellMouseEventHandler? CellMouseUp;
-        public event DataGridViewCellPaintingEventHandler CellPainting;
+        public event DataGridViewCellPaintingEventHandler? CellPainting;
-        public event DataGridViewCellParsingEventHandler CellParsing;
+        public event DataGridViewCellParsingEventHandler? CellParsing;
-        public event DataGridViewCellStateChangedEventHandler CellStateChanged;
+        public event DataGridViewCellStateChangedEventHandler? CellStateChanged;
-        public event DataGridViewCellEventHandler CellStyleChanged;
+        public event DataGridViewCellEventHandler? CellStyleChanged;
-        public event DataGridViewCellStyleContentChangedEventHandler CellStyleContentChanged;
+        public event DataGridViewCellStyleContentChangedEventHandler? CellStyleContentChanged;
-        public event DataGridViewCellEventHandler CellToolTipTextChanged;
+        public event DataGridViewCellEventHandler? CellToolTipTextChanged;
-        public event DataGridViewCellToolTipTextNeededEventHandler CellToolTipTextNeeded;
+        public event DataGridViewCellToolTipTextNeededEventHandler? CellToolTipTextNeeded;
-        public event DataGridViewCellEventHandler CellValidated;
+        public event DataGridViewCellEventHandler? CellValidated;
-        public event DataGridViewCellValidatingEventHandler CellValidating;
+        public event DataGridViewCellValidatingEventHandler? CellValidating;
-        public event DataGridViewCellEventHandler CellValueChanged;
+        public event DataGridViewCellEventHandler? CellValueChanged;
-        public event DataGridViewCellValueEventHandler CellValueNeeded;
+        public event DataGridViewCellValueEventHandler? CellValueNeeded;
-        public event DataGridViewCellValueEventHandler CellValuePushed;
+        public event DataGridViewCellValueEventHandler? CellValuePushed;
-        public event DataGridViewColumnEventHandler ColumnAdded;
+        public event DataGridViewColumnEventHandler? ColumnAdded;
-        public event DataGridViewColumnEventHandler ColumnContextMenuStripChanged;
+        public event DataGridViewColumnEventHandler? ColumnContextMenuStripChanged;
-        public event DataGridViewColumnEventHandler ColumnDataPropertyNameChanged;
+        public event DataGridViewColumnEventHandler? ColumnDataPropertyNameChanged;
-        public event DataGridViewColumnEventHandler ColumnDefaultCellStyleChanged;
+        public event DataGridViewColumnEventHandler? ColumnDefaultCellStyleChanged;
-        public event DataGridViewColumnEventHandler ColumnDisplayIndexChanged;
+        public event DataGridViewColumnEventHandler? ColumnDisplayIndexChanged;
-        public event DataGridViewColumnDividerDoubleClickEventHandler ColumnDividerDoubleClick;
+        public event DataGridViewColumnDividerDoubleClickEventHandler? ColumnDividerDoubleClick;
-        public event DataGridViewColumnEventHandler ColumnDividerWidthChanged;
+        public event DataGridViewColumnEventHandler? ColumnDividerWidthChanged;
-        public event DataGridViewColumnEventHandler ColumnHeaderCellChanged;
+        public event DataGridViewColumnEventHandler? ColumnHeaderCellChanged;
-        public event DataGridViewCellMouseEventHandler ColumnHeaderMouseClick;
+        public event DataGridViewCellMouseEventHandler? ColumnHeaderMouseClick;
-        public event DataGridViewCellMouseEventHandler ColumnHeaderMouseDoubleClick;
+        public event DataGridViewCellMouseEventHandler? ColumnHeaderMouseDoubleClick;
-        public event EventHandler ColumnHeadersBorderStyleChanged;
+        public event EventHandler? ColumnHeadersBorderStyleChanged;
-        public event EventHandler ColumnHeadersDefaultCellStyleChanged;
+        public event EventHandler? ColumnHeadersDefaultCellStyleChanged;
-        public event EventHandler ColumnHeadersHeightChanged;
+        public event EventHandler? ColumnHeadersHeightChanged;
-        public event DataGridViewAutoSizeModeEventHandler ColumnHeadersHeightSizeModeChanged;
+        public event DataGridViewAutoSizeModeEventHandler? ColumnHeadersHeightSizeModeChanged;
-        public event DataGridViewColumnEventHandler ColumnMinimumWidthChanged;
+        public event DataGridViewColumnEventHandler? ColumnMinimumWidthChanged;
-        public event DataGridViewColumnEventHandler ColumnNameChanged;
+        public event DataGridViewColumnEventHandler? ColumnNameChanged;
-        public event DataGridViewColumnEventHandler ColumnRemoved;
+        public event DataGridViewColumnEventHandler? ColumnRemoved;
-        public event DataGridViewColumnEventHandler ColumnSortModeChanged;
+        public event DataGridViewColumnEventHandler? ColumnSortModeChanged;
-        public event DataGridViewColumnStateChangedEventHandler ColumnStateChanged;
+        public event DataGridViewColumnStateChangedEventHandler? ColumnStateChanged;
-        public event DataGridViewColumnEventHandler ColumnToolTipTextChanged;
+        public event DataGridViewColumnEventHandler? ColumnToolTipTextChanged;
-        public event DataGridViewColumnEventHandler ColumnWidthChanged;
+        public event DataGridViewColumnEventHandler? ColumnWidthChanged;
-        public event EventHandler CurrentCellChanged;
+        public event EventHandler? CurrentCellChanged;
-        public event EventHandler CurrentCellDirtyStateChanged;
+        public event EventHandler? CurrentCellDirtyStateChanged;
-        public event DataGridViewBindingCompleteEventHandler DataBindingComplete;
+        public event DataGridViewBindingCompleteEventHandler? DataBindingComplete;
-        public event DataGridViewDataErrorEventHandler DataError;
+        public event DataGridViewDataErrorEventHandler? DataError;
-        public event EventHandler DataMemberChanged;
+        public event EventHandler? DataMemberChanged;
-        public event EventHandler DataSourceChanged;
+        public event EventHandler? DataSourceChanged;
-        public event EventHandler DefaultCellStyleChanged;
+        public event EventHandler? DefaultCellStyleChanged;
-        public event DataGridViewRowEventHandler DefaultValuesNeeded;
+        public event DataGridViewRowEventHandler? DefaultValuesNeeded;
-        public event DataGridViewEditingControlShowingEventHandler EditingControlShowing;
+        public event DataGridViewEditingControlShowingEventHandler? EditingControlShowing;
-        public event EventHandler EditModeChanged;
+        public event EventHandler? EditModeChanged;
-        public new event EventHandler FontChanged;
+        public new event EventHandler? FontChanged;
-        public new event EventHandler ForeColorChanged;
+        public new event EventHandler? ForeColorChanged;
-        public event EventHandler GridColorChanged;
+        public event EventHandler? GridColorChanged;
-        public event EventHandler MultiSelectChanged;
+        public event EventHandler? MultiSelectChanged;
-        public event DataGridViewRowEventHandler NewRowNeeded;
+        public event DataGridViewRowEventHandler? NewRowNeeded;
-        public new event EventHandler PaddingChanged;
+        public new event EventHandler? PaddingChanged;
-        public event EventHandler ReadOnlyChanged;
+        public event EventHandler? ReadOnlyChanged;
-        public event DataGridViewRowEventHandler RowContextMenuStripChanged;
+        public event DataGridViewRowEventHandler? RowContextMenuStripChanged;
-        public event DataGridViewRowContextMenuStripNeededEventHandler RowContextMenuStripNeeded;
+        public event DataGridViewRowContextMenuStripNeededEventHandler? RowContextMenuStripNeeded;
-        public event DataGridViewRowEventHandler RowDefaultCellStyleChanged;
+        public event DataGridViewRowEventHandler? RowDefaultCellStyleChanged;
-        public event QuestionEventHandler RowDirtyStateNeeded;
+        public event QuestionEventHandler? RowDirtyStateNeeded;
-        public event DataGridViewRowDividerDoubleClickEventHandler RowDividerDoubleClick;
+        public event DataGridViewRowDividerDoubleClickEventHandler? RowDividerDoubleClick;
-        public event DataGridViewRowEventHandler RowDividerHeightChanged;
+        public event DataGridViewRowEventHandler? RowDividerHeightChanged;
-        public event DataGridViewCellEventHandler RowEnter;
+        public event DataGridViewCellEventHandler? RowEnter;
-        public event DataGridViewRowEventHandler RowErrorTextChanged;
+        public event DataGridViewRowEventHandler? RowErrorTextChanged;
-        public event DataGridViewRowErrorTextNeededEventHandler RowErrorTextNeeded;
+        public event DataGridViewRowErrorTextNeededEventHandler? RowErrorTextNeeded;
-        public event DataGridViewRowEventHandler RowHeaderCellChanged;
+        public event DataGridViewRowEventHandler? RowHeaderCellChanged;
-        public event DataGridViewCellMouseEventHandler RowHeaderMouseClick;
+        public event DataGridViewCellMouseEventHandler? RowHeaderMouseClick;
-        public event DataGridViewCellMouseEventHandler RowHeaderMouseDoubleClick;
+        public event DataGridViewCellMouseEventHandler? RowHeaderMouseDoubleClick;
-        public event EventHandler RowHeadersBorderStyleChanged;
+        public event EventHandler? RowHeadersBorderStyleChanged;
-        public event EventHandler RowHeadersDefaultCellStyleChanged;
+        public event EventHandler? RowHeadersDefaultCellStyleChanged;
-        public event EventHandler RowHeadersWidthChanged;
+        public event EventHandler? RowHeadersWidthChanged;
-        public event DataGridViewAutoSizeModeEventHandler RowHeadersWidthSizeModeChanged;
+        public event DataGridViewAutoSizeModeEventHandler? RowHeadersWidthSizeModeChanged;
-        public event DataGridViewRowEventHandler RowHeightChanged;
+        public event DataGridViewRowEventHandler? RowHeightChanged;
-        public event DataGridViewRowHeightInfoNeededEventHandler RowHeightInfoNeeded;
+        public event DataGridViewRowHeightInfoNeededEventHandler? RowHeightInfoNeeded;
-        public event DataGridViewRowHeightInfoPushedEventHandler RowHeightInfoPushed;
+        public event DataGridViewRowHeightInfoPushedEventHandler? RowHeightInfoPushed;
-        public event DataGridViewCellEventHandler RowLeave;
+        public event DataGridViewCellEventHandler? RowLeave;
-        public event DataGridViewRowEventHandler RowMinimumHeightChanged;
+        public event DataGridViewRowEventHandler? RowMinimumHeightChanged;
-        public event DataGridViewRowPostPaintEventHandler RowPostPaint;
+        public event DataGridViewRowPostPaintEventHandler? RowPostPaint;
-        public event DataGridViewRowPrePaintEventHandler RowPrePaint;
+        public event DataGridViewRowPrePaintEventHandler? RowPrePaint;
-        public event DataGridViewRowsAddedEventHandler RowsAdded;
+        public event DataGridViewRowsAddedEventHandler? RowsAdded;
-        public event EventHandler RowsDefaultCellStyleChanged;
+        public event EventHandler? RowsDefaultCellStyleChanged;
-        public event DataGridViewRowsRemovedEventHandler RowsRemoved;
+        public event DataGridViewRowsRemovedEventHandler? RowsRemoved;
-        public event DataGridViewRowStateChangedEventHandler RowStateChanged;
+        public event DataGridViewRowStateChangedEventHandler? RowStateChanged;
-        public event DataGridViewRowEventHandler RowUnshared;
+        public event DataGridViewRowEventHandler? RowUnshared;
-        public event DataGridViewCellEventHandler RowValidated;
+        public event DataGridViewCellEventHandler? RowValidated;
-        public event DataGridViewCellCancelEventHandler RowValidating;
+        public event DataGridViewCellCancelEventHandler? RowValidating;
-        public event ScrollEventHandler Scroll;
+        public event ScrollEventHandler? Scroll;
-        public event EventHandler SelectionChanged;
+        public event EventHandler? SelectionChanged;
-        public event DataGridViewSortCompareEventHandler SortCompare;
+        public event DataGridViewSortCompareEventHandler? SortCompare;
-        public event EventHandler Sorted;
+        public event EventHandler? Sorted;
-        public new event EventHandler StyleChanged;
+        public new event EventHandler? StyleChanged;
-        public new event EventHandler TextChanged;
+        public new event EventHandler? TextChanged;
-        public event DataGridViewRowEventHandler UserAddedRow;
+        public event DataGridViewRowEventHandler? UserAddedRow;
-        public event DataGridViewRowEventHandler UserDeletedRow;
+        public event DataGridViewRowEventHandler? UserDeletedRow;
-        public event DataGridViewRowCancelEventHandler UserDeletingRow;
+        public event DataGridViewRowCancelEventHandler? UserDeletingRow;
-        protected override AccessibleObject GetAccessibilityObjectById(int objectId);
+        protected override AccessibleObject? GetAccessibilityObjectById(int objectId);
-        public virtual DataObject GetClipboardContent();
+        public virtual DataObject? GetClipboardContent();
-        void System.ComponentModel.ISupportInitialize.BeginInit();
+        void ISupportInitialize.BeginInit();
-        void System.ComponentModel.ISupportInitialize.EndInit();
+        void ISupportInitialize.EndInit();
     }
     public abstract class DataGridViewCell : DataGridViewElement, ICloneable, IDisposable, IKeyboardToolTip {
-        public virtual ContextMenuStrip ContextMenuStrip { get; set; }
+        public virtual ContextMenuStrip? ContextMenuStrip { get; set; }
-        public virtual object DefaultNewRowValue { get; }
+        public virtual object? DefaultNewRowValue { get; }
-        public object EditedFormattedValue { get; }
+        public object? EditedFormattedValue { get; }
-        public virtual Type EditType { get; }
+        public virtual Type? EditType { get; }
-        public object FormattedValue { get; }
+        public object? FormattedValue { get; }
-        public virtual Type FormattedValueType { get; }
+        public virtual Type? FormattedValueType { get; }
-        public DataGridViewColumn OwningColumn { get; internal set; }
+        public DataGridViewColumn? OwningColumn { get; internal set; }
-        public DataGridViewRow OwningRow { get; internal set; }
+        public DataGridViewRow? OwningRow { get; internal set; }
-        public object Tag { get; set; }
+        public object? Tag { get; set; }
-        public object Value { get; set; }
+        public object? Value { get; set; }
-        public virtual Type ValueType { get; set; }
+        public virtual Type? ValueType { get; set; }
-        protected virtual object GetClipboardContent(int rowIndex, bool firstCell, bool lastCell, bool inFirstRow, bool inLastRow, string format);
+        protected virtual object? GetClipboardContent(int rowIndex, bool firstCell, bool lastCell, bool inFirstRow, bool inLastRow, string format);
-        public object GetEditedFormattedValue(int rowIndex, DataGridViewDataErrorContexts context);
+        public object? GetEditedFormattedValue(int rowIndex, DataGridViewDataErrorContexts context);
-        protected virtual object GetFormattedValue(object value, int rowIndex, ref DataGridViewCellStyle cellStyle, TypeConverter valueTypeConverter, TypeConverter formattedValueTypeConverter, DataGridViewDataErrorContexts context);
+        protected virtual object? GetFormattedValue(object? value, int rowIndex, ref DataGridViewCellStyle cellStyle, TypeConverter? valueTypeConverter, TypeConverter? formattedValueTypeConverter, DataGridViewDataErrorContexts context);
-        public virtual ContextMenuStrip GetInheritedContextMenuStrip(int rowIndex);
+        public virtual ContextMenuStrip? GetInheritedContextMenuStrip(int rowIndex);
-        public virtual DataGridViewCellStyle GetInheritedStyle(DataGridViewCellStyle inheritedCellStyle, int rowIndex, bool includeColors);
+        public virtual DataGridViewCellStyle GetInheritedStyle(DataGridViewCellStyle? inheritedCellStyle, int rowIndex, bool includeColors);
-        protected virtual object GetValue(int rowIndex);
+        protected virtual object? GetValue(int rowIndex);
-        public virtual void InitializeEditingControl(int rowIndex, object initialFormattedValue, DataGridViewCellStyle dataGridViewCellStyle);
+        public virtual void InitializeEditingControl(int rowIndex, object? initialFormattedValue, DataGridViewCellStyle dataGridViewCellStyle);
-        public static int MeasureTextHeight(Graphics graphics, string text, Font font, int maxWidth, TextFormatFlags flags);
+        public static int MeasureTextHeight(Graphics graphics, string? text, Font font, int maxWidth, TextFormatFlags flags);
-        public static int MeasureTextHeight(Graphics graphics, string text, Font font, int maxWidth, TextFormatFlags flags, out bool widthTruncated);
+        public static int MeasureTextHeight(Graphics graphics, string? text, Font font, int maxWidth, TextFormatFlags flags, out bool widthTruncated);
-        public static Size MeasureTextPreferredSize(Graphics graphics, string text, Font font, float maxRatio, TextFormatFlags flags);
+        public static Size MeasureTextPreferredSize(Graphics graphics, string? text, Font font, float maxRatio, TextFormatFlags flags);
-        public static Size MeasureTextSize(Graphics graphics, string text, Font font, TextFormatFlags flags);
+        public static Size MeasureTextSize(Graphics graphics, string? text, Font font, TextFormatFlags flags);
-        public static int MeasureTextWidth(Graphics graphics, string text, Font font, int maxHeight, TextFormatFlags flags);
+        public static int MeasureTextWidth(Graphics graphics, string? text, Font font, int maxHeight, TextFormatFlags flags);
-        protected virtual void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates cellState, object value, object formattedValue, string errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts);
+        protected virtual void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates cellState, object? value, object? formattedValue, string? errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts);
-        protected virtual void PaintErrorIcon(Graphics graphics, Rectangle clipBounds, Rectangle cellValueBounds, string errorText);
+        protected virtual void PaintErrorIcon(Graphics graphics, Rectangle clipBounds, Rectangle cellValueBounds, string? errorText);
-        public virtual object ParseFormattedValue(object formattedValue, DataGridViewCellStyle cellStyle, TypeConverter formattedValueTypeConverter, TypeConverter valueTypeConverter);
+        public virtual object? ParseFormattedValue(object? formattedValue, DataGridViewCellStyle cellStyle, TypeConverter? formattedValueTypeConverter, TypeConverter? valueTypeConverter);
-        protected virtual bool SetValue(int rowIndex, object value);
+        protected virtual bool SetValue(int rowIndex, object? value);
     }
     public class DataGridViewCellCollection : BaseCollection, ICollection, IEnumerable, IList {
-        int System.Collections.ICollection.Count { get; }
+        int ICollection.Count { get; }
-        bool System.Collections.ICollection.IsSynchronized { get; }
+        bool ICollection.IsSynchronized { get; }
-        object System.Collections.ICollection.SyncRoot { get; }
+        object ICollection.SyncRoot { get; }
-        bool System.Collections.IList.IsFixedSize { get; }
+        bool IList.IsFixedSize { get; }
-        bool System.Collections.IList.IsReadOnly { get; }
+        bool IList.IsReadOnly { get; }
-        object System.Collections.IList.this[int index] { get; set; }
+        object? IList.this[int index] { get; set; }
-        public event CollectionChangeEventHandler CollectionChanged;
+        public event CollectionChangeEventHandler? CollectionChanged;
-        void System.Collections.ICollection.CopyTo(Array array, int index);
+        void ICollection.CopyTo(Array array, int index);
-        IEnumerator System.Collections.IEnumerable.GetEnumerator();
+        IEnumerator IEnumerable.GetEnumerator();
-        int System.Collections.IList.Add(object value);
+        int IList.Add(object? value);
-        void System.Collections.IList.Clear();
+        void IList.Clear();
-        bool System.Collections.IList.Contains(object value);
+        bool IList.Contains(object? value);
-        int System.Collections.IList.IndexOf(object value);
+        int IList.IndexOf(object? value);
-        void System.Collections.IList.Insert(int index, object value);
+        void IList.Insert(int index, object? value);
-        void System.Collections.IList.Remove(object value);
+        void IList.Remove(object? value);
-        void System.Collections.IList.RemoveAt(int index);
+        void IList.RemoveAt(int index);
     }
     public class DataGridViewCellFormattingEventArgs : ConvertEventArgs {
-        public DataGridViewCellFormattingEventArgs(int columnIndex, int rowIndex, object value, Type desiredType, DataGridViewCellStyle cellStyle);
+        public DataGridViewCellFormattingEventArgs(int columnIndex, int rowIndex, object? value, Type? desiredType, DataGridViewCellStyle cellStyle);
     }
     public class DataGridViewCellStyle : ICloneable {
-        public object DataSourceNullValue { get; set; }
+        public object? DataSourceNullValue { get; set; }
-        public object NullValue { get; set; }
+        public object? NullValue { get; set; }
-        public object Tag { get; set; }
+        public object? Tag { get; set; }
-        public override bool Equals(object o);
+        public override bool Equals(object? o);
-        object System.ICloneable.Clone();
+        object ICloneable.Clone();
     }
     public class DataGridViewCheckBoxCell : DataGridViewCell, IDataGridViewEditingCell {
-        public virtual object EditingCellFormattedValue { get; set; }
+        public virtual object? EditingCellFormattedValue { get; set; }
-        public override Type EditType { get; }
+        public override Type? EditType { get; }
-        public object FalseValue { get; set; }
+        public object? FalseValue { get; set; }
-        public object IndeterminateValue { get; set; }
+        public object? IndeterminateValue { get; set; }
-        public object TrueValue { get; set; }
+        public object? TrueValue { get; set; }
-        public override Type ValueType { get; set; }
+        public override Type? ValueType { get; set; }
-        public virtual object GetEditingCellFormattedValue(DataGridViewDataErrorContexts context);
+        public virtual object? GetEditingCellFormattedValue(DataGridViewDataErrorContexts context);
-        protected override object GetFormattedValue(object value, int rowIndex, ref DataGridViewCellStyle cellStyle, TypeConverter valueTypeConverter, TypeConverter formattedValueTypeConverter, DataGridViewDataErrorContexts context);
+        protected override object? GetFormattedValue(object? value, int rowIndex, ref DataGridViewCellStyle cellStyle, TypeConverter? valueTypeConverter, TypeConverter? formattedValueTypeConverter, DataGridViewDataErrorContexts context);
-        protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates elementState, object value, object formattedValue, string errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts);
+        protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates elementState, object? value, object? formattedValue, string? errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts);
-        public override object ParseFormattedValue(object formattedValue, DataGridViewCellStyle cellStyle, TypeConverter formattedValueTypeConverter, TypeConverter valueTypeConverter);
+        public override object? ParseFormattedValue(object? formattedValue, DataGridViewCellStyle cellStyle, TypeConverter? formattedValueTypeConverter, TypeConverter? valueTypeConverter);
     }
     public class DataGridViewColumnCollection : BaseCollection, ICollection, IEnumerable, IList {
-        int System.Collections.ICollection.Count { get; }
+        int ICollection.Count { get; }
-        bool System.Collections.ICollection.IsSynchronized { get; }
+        bool ICollection.IsSynchronized { get; }
-        object System.Collections.ICollection.SyncRoot { get; }
+        object ICollection.SyncRoot { get; }
-        bool System.Collections.IList.IsFixedSize { get; }
+        bool IList.IsFixedSize { get; }
-        bool System.Collections.IList.IsReadOnly { get; }
+        bool IList.IsReadOnly { get; }
-        object System.Collections.IList.this[int index] { get; set; }
+        object? IList.this[int index] { get; set; }
-        public DataGridViewColumn this[string columnName] { get; }
+        public DataGridViewColumn? this[string columnName] { get; }
-        public event CollectionChangeEventHandler CollectionChanged;
+        public event CollectionChangeEventHandler? CollectionChanged;
-        public virtual int Add(string columnName, string headerText);
+        public virtual int Add(string? columnName, string? headerText);
-        public DataGridViewColumn GetFirstColumn(DataGridViewElementStates includeFilter);
+        public DataGridViewColumn? GetFirstColumn(DataGridViewElementStates includeFilter);
-        public DataGridViewColumn GetFirstColumn(DataGridViewElementStates includeFilter, DataGridViewElementStates excludeFilter);
+        public DataGridViewColumn? GetFirstColumn(DataGridViewElementStates includeFilter, DataGridViewElementStates excludeFilter);
-        public DataGridViewColumn GetLastColumn(DataGridViewElementStates includeFilter, DataGridViewElementStates excludeFilter);
+        public DataGridViewColumn? GetLastColumn(DataGridViewElementStates includeFilter, DataGridViewElementStates excludeFilter);
-        public DataGridViewColumn GetNextColumn(DataGridViewColumn dataGridViewColumnStart, DataGridViewElementStates includeFilter, DataGridViewElementStates excludeFilter);
+        public DataGridViewColumn? GetNextColumn(DataGridViewColumn dataGridViewColumnStart, DataGridViewElementStates includeFilter, DataGridViewElementStates excludeFilter);
-        public DataGridViewColumn GetPreviousColumn(DataGridViewColumn dataGridViewColumnStart, DataGridViewElementStates includeFilter, DataGridViewElementStates excludeFilter);
+        public DataGridViewColumn? GetPreviousColumn(DataGridViewColumn dataGridViewColumnStart, DataGridViewElementStates includeFilter, DataGridViewElementStates excludeFilter);
-        void System.Collections.ICollection.CopyTo(Array array, int index);
+        void ICollection.CopyTo(Array array, int index);
-        IEnumerator System.Collections.IEnumerable.GetEnumerator();
+        IEnumerator IEnumerable.GetEnumerator();
-        int System.Collections.IList.Add(object value);
+        int IList.Add(object? value);
-        void System.Collections.IList.Clear();
+        void IList.Clear();
-        bool System.Collections.IList.Contains(object value);
+        bool IList.Contains(object? value);
-        int System.Collections.IList.IndexOf(object value);
+        int IList.IndexOf(object? value);
-        void System.Collections.IList.Insert(int index, object value);
+        void IList.Insert(int index, object? value);
-        void System.Collections.IList.Remove(object value);
+        void IList.Remove(object? value);
-        void System.Collections.IList.RemoveAt(int index);
+        void IList.RemoveAt(int index);
     }
     public class DataGridViewColumnHeaderCell : DataGridViewHeaderCell {
-        protected override object GetClipboardContent(int rowIndex, bool firstCell, bool lastCell, bool inFirstRow, bool inLastRow, string format);
+        protected override object? GetClipboardContent(int rowIndex, bool firstCell, bool lastCell, bool inFirstRow, bool inLastRow, string format);
-        public override ContextMenuStrip GetInheritedContextMenuStrip(int rowIndex);
+        public override ContextMenuStrip? GetInheritedContextMenuStrip(int rowIndex);
-        public override DataGridViewCellStyle GetInheritedStyle(DataGridViewCellStyle inheritedCellStyle, int rowIndex, bool includeColors);
+        public override DataGridViewCellStyle GetInheritedStyle(DataGridViewCellStyle? inheritedCellStyle, int rowIndex, bool includeColors);
-        protected override object GetValue(int rowIndex);
+        protected override object? GetValue(int rowIndex);
-        protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates dataGridViewElementState, object value, object formattedValue, string errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts);
+        protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates dataGridViewElementState, object? value, object? formattedValue, string? errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts);
-        protected override bool SetValue(int rowIndex, object value);
+        protected override bool SetValue(int rowIndex, object? value);
     }
     public class DataGridViewComboBoxCell : DataGridViewCell {
-        public virtual object DataSource { get; set; }
+        public virtual object? DataSource { get; set; }
-        protected override object GetFormattedValue(object value, int rowIndex, ref DataGridViewCellStyle cellStyle, TypeConverter valueTypeConverter, TypeConverter formattedValueTypeConverter, DataGridViewDataErrorContexts context);
+        protected override object? GetFormattedValue(object? value, int rowIndex, ref DataGridViewCellStyle cellStyle, TypeConverter? valueTypeConverter, TypeConverter? formattedValueTypeConverter, DataGridViewDataErrorContexts context);
-        public override void InitializeEditingControl(int rowIndex, object initialFormattedValue, DataGridViewCellStyle dataGridViewCellStyle);
+        public override void InitializeEditingControl(int rowIndex, object? initialFormattedValue, DataGridViewCellStyle dataGridViewCellStyle);
-        protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates elementState, object value, object formattedValue, string errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts);
+        protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates elementState, object? value, object? formattedValue, string? errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts);
-        public override object ParseFormattedValue(object formattedValue, DataGridViewCellStyle cellStyle, TypeConverter formattedValueTypeConverter, TypeConverter valueTypeConverter);
+        public override object? ParseFormattedValue(object? formattedValue, DataGridViewCellStyle cellStyle, TypeConverter? formattedValueTypeConverter, TypeConverter? valueTypeConverter);
         public class ObjectCollection : ICollection, IEnumerable, IList {
-            bool System.Collections.ICollection.IsSynchronized { get; }
+            bool ICollection.IsSynchronized { get; }
-            object System.Collections.ICollection.SyncRoot { get; }
+            object ICollection.SyncRoot { get; }
-            bool System.Collections.IList.IsFixedSize { get; }
+            bool IList.IsFixedSize { get; }
-            public virtual object this[int index] { get; set; }
+            public virtual object? this[int index] { get; set; }
-            public bool Contains(object value);
+            public bool Contains(object? value);
-            public int IndexOf(object value);
+            public int IndexOf(object? value);
-            public void Insert(int index, object item);
+            public void Insert(int index, object? item);
-            public void Remove(object value);
+            public void Remove(object? value);
-            void System.Collections.ICollection.CopyTo(Array destination, int index);
+            void ICollection.CopyTo(Array destination, int index);
-            int System.Collections.IList.Add(object item);
+            int IList.Add(object? item);
         }
     }
     public class DataGridViewComboBoxColumn : DataGridViewColumn {
-        public override DataGridViewCell CellTemplate { get; set; }
+        public override DataGridViewCell? CellTemplate { get; set; }
-        public object DataSource { get; set; }
+        public object? DataSource { get; set; }
     }
     public class DataGridViewComboBoxEditingControl : ComboBox, IDataGridViewEditingControl {
-        protected override void OnHandleCreated(EventArgs e);

     }
     public class DataGridViewHeaderCell : DataGridViewCell {
-        public override Type ValueType { get; set; }
+        public override Type? ValueType { get; set; }
-        public override ContextMenuStrip GetInheritedContextMenuStrip(int rowIndex);
+        public override ContextMenuStrip? GetInheritedContextMenuStrip(int rowIndex);
-        protected override object GetValue(int rowIndex);
+        protected override object? GetValue(int rowIndex);
-        protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates dataGridViewElementState, object value, object formattedValue, string errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts);
+        protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates dataGridViewElementState, object? value, object? formattedValue, string? errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts);
     }
     public class DataGridViewImageCell : DataGridViewCell {
-        public override object DefaultNewRowValue { get; }
+        public override object? DefaultNewRowValue { get; }
-        public override Type EditType { get; }
+        public override Type? EditType { get; }
-        public override Type ValueType { get; set; }
+        public override Type? ValueType { get; set; }
-        protected override object GetFormattedValue(object value, int rowIndex, ref DataGridViewCellStyle cellStyle, TypeConverter valueTypeConverter, TypeConverter formattedValueTypeConverter, DataGridViewDataErrorContexts context);
+        protected override object? GetFormattedValue(object? value, int rowIndex, ref DataGridViewCellStyle cellStyle, TypeConverter? valueTypeConverter, TypeConverter? formattedValueTypeConverter, DataGridViewDataErrorContexts context);
-        protected override object GetValue(int rowIndex);
+        protected override object? GetValue(int rowIndex);
-        protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates elementState, object value, object formattedValue, string errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts);
+        protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates elementState, object? value, object? formattedValue, string? errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts);
     }
     public class DataGridViewLinkCell : DataGridViewCell {
-        public override Type EditType { get; }
+        public override Type? EditType { get; }
-        public override Type FormattedValueType { get; }
+        public override Type? FormattedValueType { get; }
-        protected override object GetValue(int rowIndex);
+        protected override object? GetValue(int rowIndex);
-        protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates cellState, object value, object formattedValue, string errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts);
+        protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates cellState, object? value, object? formattedValue, string? errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts);
     }
     public class DataGridViewRow : DataGridViewBand {
-        public override ContextMenuStrip ContextMenuStrip { get; set; }
+        public override ContextMenuStrip? ContextMenuStrip { get; set; }
-        public object DataBoundItem { get; }
+        public object? DataBoundItem { get; }
-        public ContextMenuStrip GetContextMenuStrip(int rowIndex);
+        public ContextMenuStrip? GetContextMenuStrip(int rowIndex);
     }
     public class DataGridViewRowCollection : ICollection, IEnumerable, IList {
-        int System.Collections.ICollection.Count { get; }
+        int ICollection.Count { get; }
-        bool System.Collections.ICollection.IsSynchronized { get; }
+        bool ICollection.IsSynchronized { get; }
-        object System.Collections.ICollection.SyncRoot { get; }
+        object ICollection.SyncRoot { get; }
-        bool System.Collections.IList.IsFixedSize { get; }
+        bool IList.IsFixedSize { get; }
-        bool System.Collections.IList.IsReadOnly { get; }
+        bool IList.IsReadOnly { get; }
-        object System.Collections.IList.this[int index] { get; set; }
+        object? IList.this[int index] { get; set; }
-        public event CollectionChangeEventHandler CollectionChanged;
+        public event CollectionChangeEventHandler? CollectionChanged;
-        void System.Collections.ICollection.CopyTo(Array array, int index);
+        void ICollection.CopyTo(Array array, int index);
-        IEnumerator System.Collections.IEnumerable.GetEnumerator();
+        IEnumerator IEnumerable.GetEnumerator();
-        int System.Collections.IList.Add(object value);
+        int IList.Add(object? value);
-        void System.Collections.IList.Clear();
+        void IList.Clear();
-        bool System.Collections.IList.Contains(object value);
+        bool IList.Contains(object? value);
-        int System.Collections.IList.IndexOf(object value);
+        int IList.IndexOf(object? value);
-        void System.Collections.IList.Insert(int index, object value);
+        void IList.Insert(int index, object? value);
-        void System.Collections.IList.Remove(object value);
+        void IList.Remove(object? value);
-        void System.Collections.IList.RemoveAt(int index);
+        void IList.RemoveAt(int index);
     }
     public class DataGridViewRowHeaderCell : DataGridViewHeaderCell {
-        protected override object GetClipboardContent(int rowIndex, bool firstCell, bool lastCell, bool inFirstRow, bool inLastRow, string format);
+        protected override object? GetClipboardContent(int rowIndex, bool firstCell, bool lastCell, bool inFirstRow, bool inLastRow, string format);
-        public override ContextMenuStrip GetInheritedContextMenuStrip(int rowIndex);
+        public override ContextMenuStrip? GetInheritedContextMenuStrip(int rowIndex);
-        public override DataGridViewCellStyle GetInheritedStyle(DataGridViewCellStyle inheritedCellStyle, int rowIndex, bool includeColors);
+        public override DataGridViewCellStyle GetInheritedStyle(DataGridViewCellStyle? inheritedCellStyle, int rowIndex, bool includeColors);
-        protected override object GetValue(int rowIndex);
+        protected override object? GetValue(int rowIndex);
-        protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates cellState, object value, object formattedValue, string errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts);
+        protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates cellState, object? value, object? formattedValue, string? errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts);
-        protected override bool SetValue(int rowIndex, object value);
+        protected override bool SetValue(int rowIndex, object? value);
     }
     public class DataGridViewTextBoxCell : DataGridViewCell {
-        public override void InitializeEditingControl(int rowIndex, object initialFormattedValue, DataGridViewCellStyle dataGridViewCellStyle);
+        public override void InitializeEditingControl(int rowIndex, object? initialFormattedValue, DataGridViewCellStyle dataGridViewCellStyle);
-        protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates cellState, object value, object formattedValue, string errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts);
+        protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates cellState, object? value, object? formattedValue, string? errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts);
         protected class DataGridViewTextBoxCellAccessibleObject : DataGridViewCell.DataGridViewCellAccessibleObject {
-            public DataGridViewTextBoxCellAccessibleObject(DataGridViewCell owner);
+            public DataGridViewTextBoxCellAccessibleObject(DataGridViewCell? owner);
         }
     }
     public class DataGridViewTextBoxEditingControl : TextBox, IDataGridViewEditingControl {
-        protected override void OnHandleCreated(EventArgs e);

     }
     public sealed class FolderBrowserDialog : CommonDialog {
+        public bool Multiselect { get; set; }
+        public string[] SelectedPaths { get; }
     }
     public sealed class HtmlElement {
-        public HtmlElement AppendChild(HtmlElement newElement);
+        public HtmlElement? AppendChild(HtmlElement newElement);
-        public HtmlElement InsertAdjacentElement(HtmlElementInsertionOrientation orient, HtmlElement newElement);
+        public HtmlElement? InsertAdjacentElement(HtmlElementInsertionOrientation orient, HtmlElement newElement);
-        public object InvokeMember(string methodName);
+        public object? InvokeMember(string methodName);
-        public object InvokeMember(string methodName, params object[] parameter);
+        public object? InvokeMember(string methodName, params object[]? parameter);
     }
     public sealed class HtmlWindow {
-        public HtmlWindow Open(string urlString, string target, string windowOptions, bool replaceEntry);
+        public HtmlWindow? Open(string urlString, string target, string windowOptions, bool replaceEntry);
-        public HtmlWindow Open(Uri url, string target, string windowOptions, bool replaceEntry);
+        public HtmlWindow? Open(Uri url, string target, string windowOptions, bool replaceEntry);
-        public HtmlWindow OpenNew(string urlString, string windowOptions);
+        public HtmlWindow? OpenNew(string urlString, string windowOptions);
-        public HtmlWindow OpenNew(Uri url, string windowOptions);
+        public HtmlWindow? OpenNew(Uri url, string windowOptions);
-        public string Prompt(string message, string defaultInputValue);
+        public string? Prompt(string message, string defaultInputValue);
     }
     public sealed class ImageList : Component, IHandle<HIMAGELIST> {
         public sealed class ImageCollection : ICollection, IEnumerable, IList {
-            public void AddRange(Image[] images);
+            public void AddRange(params Image[] images);
         }
     }
     public class LinkLabel : Label, IButtonControl {
+        protected override void Dispose(bool disposing);
     }
     public static class ListBindingHelper {
-        public static Type? GetListItemType(object? dataSource, string? dataMember);
+        public static Type GetListItemType(object? dataSource, string? dataMember);
     }
     public class ListBox : ListControl {
         public class IntegerCollection : ICollection, IEnumerable, IList {
-            public void AddRange(int[] items);
+            public void AddRange(params int[] items);
         }
         public class ObjectCollection : ICollection, IEnumerable, IList {
-            public void AddRange(object[] items);
+            public void AddRange(params object[] items);
         }
     }
     public class ListView : Control {
         public class ColumnHeaderCollection : ICollection, IEnumerable, IList {
-            public virtual void AddRange(ColumnHeader[] values);
+            public virtual void AddRange(params ColumnHeader[] values);
         }
         public class ListViewItemCollection : ICollection, IEnumerable, IList {
-            public void AddRange(ListViewItem[] items);
+            public void AddRange(params ListViewItem[] items);
         }
     }
     public class ListViewGroupCollection : ICollection, IEnumerable, IList {
-        public void AddRange(ListViewGroup[] groups);
+        public void AddRange(params ListViewGroup[] groups);
     }
     public class ListViewItem : ICloneable, IKeyboardToolTip, ISerializable {
         public class ListViewSubItemCollection : ICollection, IEnumerable, IList {
-            public void AddRange(ListViewItem.ListViewSubItem[] items);
+            public void AddRange(params ListViewItem.ListViewSubItem[] items);
-            public void AddRange(string[] items);
+            public void AddRange(params string[] items);
         }
     }
     public class PictureBox : Control, ISupportInitialize {
-        void System.ComponentModel.ISupportInitialize.BeginInit();
+        void ISupportInitialize.BeginInit();
-        void System.ComponentModel.ISupportInitialize.EndInit();
+        void ISupportInitialize.EndInit();
     }
     public class PropertyGrid : ContainerControl, IComPropertyBrowser, IPropertyNotifySink.Interface {
-        bool System.Windows.Forms.ComponentModel.Com2Interop.IComPropertyBrowser.InPropertySet { get; }
+        bool IComPropertyBrowser.InPropertySet { get; }
-        void System.Windows.Forms.ComponentModel.Com2Interop.IComPropertyBrowser.DropDownDone();
+        void IComPropertyBrowser.DropDownDone();
-        bool System.Windows.Forms.ComponentModel.Com2Interop.IComPropertyBrowser.EnsurePendingChangesCommitted();
+        bool IComPropertyBrowser.EnsurePendingChangesCommitted();
-        void System.Windows.Forms.ComponentModel.Com2Interop.IComPropertyBrowser.HandleF4();
+        void IComPropertyBrowser.HandleF4();
-        void System.Windows.Forms.ComponentModel.Com2Interop.IComPropertyBrowser.LoadState(RegistryKey key);
+        void IComPropertyBrowser.LoadState(RegistryKey key);
-        void System.Windows.Forms.ComponentModel.Com2Interop.IComPropertyBrowser.SaveState(RegistryKey key);
+        void IComPropertyBrowser.SaveState(RegistryKey key);
     }
     public class TabControl : Control {
         public class TabPageCollection : ICollection, IEnumerable, IList {
-            public void AddRange(TabPage[] pages);
+            public void AddRange(params TabPage[] pages);
         }
     }
     public class ToolStripDropDownItemAccessibleObject : ToolStripItem.ToolStripItemAccessibleObject {
-        public override AccessibleObject GetChild(int index);
+        public override AccessibleObject? GetChild(int index);
     }
     public abstract class ToolStripItem : BindableComponent, IArrangedElement, ICommandBindingTargetProvider, IComponent, IDisposable, IDropTarget, IKeyboardToolTip, ISupportOleDropSource {
+        public event EventHandler SelectedChanged;
+        protected virtual void OnSelectedChanged(EventArgs e);
     }
     public class ToolStripItemCollection : ArrangedElementCollection, ICollection, IEnumerable, IList {
-        public void AddRange(ToolStripItem[] toolStripItems);
+        public void AddRange(params ToolStripItem[] toolStripItems);
     }
     public class ToolStripMenuItem : ToolStripDropDownItem {
-        public ToolStripMenuItem(Image? image);
+        public ToolStripMenuItem(Image image);
-        public ToolStripMenuItem(string? text);
+        public ToolStripMenuItem(string text);
-        public ToolStripMenuItem(string? text, Image? image);
+        public ToolStripMenuItem(string text, Image image);
-        public ToolStripMenuItem(string? text, Image? image, EventHandler? onClick);
+        public ToolStripMenuItem(string text, Image image, EventHandler onClick);
-        public ToolStripMenuItem(string? text, Image? image, EventHandler? onClick, string? name);
+        public ToolStripMenuItem(string text, Image image, EventHandler onClick, string name);
-        public ToolStripMenuItem(string? text, Image? image, EventHandler? onClick, Keys shortcutKeys);
+        public ToolStripMenuItem(string text, Image image, EventHandler onClick, Keys shortcutKeys);
-        public ToolStripMenuItem(string? text, Image? image, params ToolStripItem[]? dropDownItems);
+        public ToolStripMenuItem(string text, Image image, params ToolStripItem[]? dropDownItems);
-        public string? ShortcutKeyDisplayString { get; set; }
+        public string ShortcutKeyDisplayString { get; set; }
-        public event EventHandler? CheckedChanged;
+        public event EventHandler CheckedChanged;
-        public event EventHandler? CheckStateChanged;
+        public event EventHandler CheckStateChanged;
     }
     public class ToolStripPanel : ContainerControl, IArrangedElement, IComponent, IDisposable {
         public class ToolStripPanelRowCollection : ArrangedElementCollection, ICollection, IEnumerable, IList {
-            public void AddRange(ToolStripPanelRow[] value);
+            public void AddRange(params ToolStripPanelRow[] value);
         }
     }
     public class TreeNode : MarshalByRefObject, ICloneable, IKeyboardToolTip, ISerializable {
-        public TreeNode(string text);
+        public TreeNode(string? text);
-        public TreeNode(string text, int imageIndex, int selectedImageIndex);
+        public TreeNode(string? text, int imageIndex, int selectedImageIndex);
-        public TreeNode(string text, int imageIndex, int selectedImageIndex, TreeNode[] children);
+        public TreeNode(string? text, int imageIndex, int selectedImageIndex, TreeNode[] children);
-        public TreeNode(string text, TreeNode[] children);
+        public TreeNode(string? text, TreeNode[] children);
-        public virtual ContextMenuStrip ContextMenuStrip { get; set; }
+        public virtual ContextMenuStrip? ContextMenuStrip { get; set; }
-        public TreeNode FirstNode { get; }
+        public TreeNode? FirstNode { get; }
-        public TreeNode LastNode { get; }
+        public TreeNode? LastNode { get; }
-        public TreeNode NextNode { get; }
+        public TreeNode? NextNode { get; }
-        public TreeNode NextVisibleNode { get; }
+        public TreeNode? NextVisibleNode { get; }
-        public Font NodeFont { get; set; }
+        public Font? NodeFont { get; set; }
-        public TreeNode Parent { get; }
+        public TreeNode? Parent { get; }
-        public TreeNode PrevNode { get; }
+        public TreeNode? PrevNode { get; }
-        public TreeNode PrevVisibleNode { get; }
+        public TreeNode? PrevVisibleNode { get; }
-        public object Tag { get; set; }
+        public object? Tag { get; set; }
-        public TreeView TreeView { get; }
+        public TreeView? TreeView { get; }
-        public static TreeNode FromHandle(TreeView tree, IntPtr handle);
+        public static TreeNode? FromHandle(TreeView tree, IntPtr handle);
-        void System.Runtime.Serialization.ISerializable.GetObjectData(SerializationInfo si, StreamingContext context);
+        void ISerializable.GetObjectData(SerializationInfo si, StreamingContext context);
     }
     public class TreeNodeCollection : ICollection, IEnumerable, IList {
-        public virtual void AddRange(TreeNode[] nodes);
+        public virtual void AddRange(params TreeNode[] nodes);
     }
     public class TreeView : Control {
-        protected OwnerDrawPropertyBag GetItemRenderStyles(TreeNode node, int state);
+        protected OwnerDrawPropertyBag GetItemRenderStyles(TreeNode? node, int state);
     }
 }
```

