How to: Display Option Buttons in a MenuStrip (Windows Forms)
Option buttons, also known as radio buttons, are similar to check boxes except that users can select only one at a time. Although by default the ToolStripMenuItem class does not provide option-button behavior, the class does provide check-box behavior that you can customize to implement option-button behavior for menu items in a MenuStrip control.
When the CheckOnClick property of a menu item is true
, users can click the item to toggle the display of a check mark. The Checked property indicates the current state of the item. To implement basic option-button behavior, you must ensure that when an item is selected, you set the Checked property for the previously selected item to false
.
The following procedures describe how to implement this and additional functionality in a class that inherits the ToolStripMenuItem class. The ToolStripRadioButtonMenuItem
class overrides members such as OnCheckedChanged and OnPaint to provide the selection behavior and appearance of option buttons. Additionally, this class overrides the Enabled property so that options on a submenu are disabled unless the parent item is selected.
To implement option-button selection behavior
Initialize the CheckOnClick property to
true
to enable item selection.// Called by all constructors to initialize CheckOnClick. private void Initialize() { CheckOnClick = true; }
' Called by all constructors to initialize CheckOnClick. Private Sub Initialize() CheckOnClick = True End Sub
Override the OnCheckedChanged method to clear the selection of the previously selected item when a new item is selected.
protected override void OnCheckedChanged(EventArgs e) { base.OnCheckedChanged(e); // If this item is no longer in the checked state or if its // parent has not yet been initialized, do nothing. if (!Checked || this.Parent == null) return; // Clear the checked state for all siblings. foreach (ToolStripItem item in Parent.Items) { ToolStripRadioButtonMenuItem radioItem = item as ToolStripRadioButtonMenuItem; if (radioItem != null && radioItem != this && radioItem.Checked) { radioItem.Checked = false; // Only one item can be selected at a time, // so there is no need to continue. return; } } }
Protected Overrides Sub OnCheckedChanged(ByVal e As EventArgs) MyBase.OnCheckedChanged(e) ' If this item is no longer in the checked state or if its ' parent has not yet been initialized, do nothing. If Not Checked OrElse Me.Parent Is Nothing Then Return ' Clear the checked state for all siblings. For Each item As ToolStripItem In Parent.Items Dim radioItem As ToolStripRadioButtonMenuItem = _ TryCast(item, ToolStripRadioButtonMenuItem) If radioItem IsNot Nothing AndAlso _ radioItem IsNot Me AndAlso _ radioItem.Checked Then radioItem.Checked = False ' Only one item can be selected at a time, ' so there is no need to continue. Return End If Next End Sub
Override the OnClick method to ensure that clicking an item that has already been selected will not clear the selection.
protected override void OnClick(EventArgs e) { // If the item is already in the checked state, do not call // the base method, which would toggle the value. if (Checked) return; base.OnClick(e); }
Protected Overrides Sub OnClick(ByVal e As EventArgs) ' If the item is already in the checked state, do not call ' the base method, which would toggle the value. If Checked Then Return MyBase.OnClick(e) End Sub
To modify the appearance of the option-button items
Override the OnPaint method to replace the default check-mark with an option button by using the RadioButtonRenderer class.
// Let the item paint itself, and then paint the RadioButton // where the check mark is normally displayed. protected override void OnPaint(PaintEventArgs e) { if (Image != null) { // If the client sets the Image property, the selection behavior // remains unchanged, but the RadioButton is not displayed and the // selection is indicated only by the selection rectangle. base.OnPaint(e); return; } else { // If the Image property is not set, call the base OnPaint method // with the CheckState property temporarily cleared to prevent // the check mark from being painted. CheckState currentState = this.CheckState; this.CheckState = CheckState.Unchecked; base.OnPaint(e); this.CheckState = currentState; } // Determine the correct state of the RadioButton. RadioButtonState buttonState = RadioButtonState.UncheckedNormal; if (Enabled) { if (mouseDownState) { if (Checked) buttonState = RadioButtonState.CheckedPressed; else buttonState = RadioButtonState.UncheckedPressed; } else if (mouseHoverState) { if (Checked) buttonState = RadioButtonState.CheckedHot; else buttonState = RadioButtonState.UncheckedHot; } else { if (Checked) buttonState = RadioButtonState.CheckedNormal; } } else { if (Checked) buttonState = RadioButtonState.CheckedDisabled; else buttonState = RadioButtonState.UncheckedDisabled; } // Calculate the position at which to display the RadioButton. Int32 offset = (ContentRectangle.Height - RadioButtonRenderer.GetGlyphSize( e.Graphics, buttonState).Height) / 2; Point imageLocation = new Point( ContentRectangle.Location.X + 4, ContentRectangle.Location.Y + offset); // Paint the RadioButton. RadioButtonRenderer.DrawRadioButton( e.Graphics, imageLocation, buttonState); }
' Let the item paint itself, and then paint the RadioButton ' where the check mark is normally displayed. Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs) If Image IsNot Nothing Then ' If the client sets the Image property, the selection behavior ' remains unchanged, but the RadioButton is not displayed and the ' selection is indicated only by the selection rectangle. MyBase.OnPaint(e) Return Else ' If the Image property is not set, call the base OnPaint method ' with the CheckState property temporarily cleared to prevent ' the check mark from being painted. Dim currentState As CheckState = Me.CheckState Me.CheckState = CheckState.Unchecked MyBase.OnPaint(e) Me.CheckState = currentState End If ' Determine the correct state of the RadioButton. Dim buttonState As RadioButtonState = RadioButtonState.UncheckedNormal If Enabled Then If mouseDownState Then If Checked Then buttonState = RadioButtonState.CheckedPressed Else buttonState = RadioButtonState.UncheckedPressed End If ElseIf mouseHoverState Then If Checked Then buttonState = RadioButtonState.CheckedHot Else buttonState = RadioButtonState.UncheckedHot End If Else If Checked Then buttonState = RadioButtonState.CheckedNormal End If Else If Checked Then buttonState = RadioButtonState.CheckedDisabled Else buttonState = RadioButtonState.UncheckedDisabled End If End If ' Calculate the position at which to display the RadioButton. Dim offset As Int32 = CInt((ContentRectangle.Height - _ RadioButtonRenderer.GetGlyphSize( _ e.Graphics, buttonState).Height) / 2) Dim imageLocation As Point = New Point( _ ContentRectangle.Location.X + 4, _ ContentRectangle.Location.Y + offset) ' Paint the RadioButton. RadioButtonRenderer.DrawRadioButton( _ e.Graphics, imageLocation, buttonState) End Sub
Override the OnMouseEnter, OnMouseLeave, OnMouseDown, and OnMouseUp methods to track the state of the mouse and ensure that the OnPaint method paints the correct option-button state.
private bool mouseHoverState = false; protected override void OnMouseEnter(EventArgs e) { mouseHoverState = true; // Force the item to repaint with the new RadioButton state. Invalidate(); base.OnMouseEnter(e); } protected override void OnMouseLeave(EventArgs e) { mouseHoverState = false; base.OnMouseLeave(e); } private bool mouseDownState = false; protected override void OnMouseDown(MouseEventArgs e) { mouseDownState = true; // Force the item to repaint with the new RadioButton state. Invalidate(); base.OnMouseDown(e); } protected override void OnMouseUp(MouseEventArgs e) { mouseDownState = false; base.OnMouseUp(e); }
Private mouseHoverState As Boolean = False Protected Overrides Sub OnMouseEnter(ByVal e As EventArgs) mouseHoverState = True ' Force the item to repaint with the new RadioButton state. Invalidate() MyBase.OnMouseEnter(e) End Sub Protected Overrides Sub OnMouseLeave(ByVal e As EventArgs) mouseHoverState = False MyBase.OnMouseLeave(e) End Sub Private mouseDownState As Boolean = False Protected Overrides Sub OnMouseDown(ByVal e As MouseEventArgs) mouseDownState = True ' Force the item to repaint with the new RadioButton state. Invalidate() MyBase.OnMouseDown(e) End Sub Protected Overrides Sub OnMouseUp(ByVal e As MouseEventArgs) mouseDownState = False MyBase.OnMouseUp(e) End Sub
To disable options on a submenu when the parent item is not selected
Override the Enabled property so that the item is disabled when it has a parent item with both a CheckOnClick value of
true
and a Checked value offalse
.// Enable the item only if its parent item is in the checked state // and its Enabled property has not been explicitly set to false. public override bool Enabled { get { ToolStripMenuItem ownerMenuItem = OwnerItem as ToolStripMenuItem; // Use the base value in design mode to prevent the designer // from setting the base value to the calculated value. if (!DesignMode && ownerMenuItem != null && ownerMenuItem.CheckOnClick) { return base.Enabled && ownerMenuItem.Checked; } else { return base.Enabled; } } set { base.Enabled = value; } }
' Enable the item only if its parent item is in the checked state ' and its Enabled property has not been explicitly set to false. Public Overrides Property Enabled() As Boolean Get Dim ownerMenuItem As ToolStripMenuItem = _ TryCast(OwnerItem, ToolStripMenuItem) ' Use the base value in design mode to prevent the designer ' from setting the base value to the calculated value. If Not DesignMode AndAlso ownerMenuItem IsNot Nothing AndAlso _ ownerMenuItem.CheckOnClick Then Return MyBase.Enabled AndAlso ownerMenuItem.Checked Else Return MyBase.Enabled End If End Get Set(ByVal value As Boolean) MyBase.Enabled = value End Set End Property
Override the OnOwnerChanged method to subscribe to the CheckedChanged event of the parent item.
// When OwnerItem becomes available, if it is a ToolStripMenuItem // with a CheckOnClick property value of true, subscribe to its // CheckedChanged event. protected override void OnOwnerChanged(EventArgs e) { ToolStripMenuItem ownerMenuItem = OwnerItem as ToolStripMenuItem; if (ownerMenuItem != null && ownerMenuItem.CheckOnClick) { ownerMenuItem.CheckedChanged += new EventHandler(OwnerMenuItem_CheckedChanged); } base.OnOwnerChanged(e); }
' When OwnerItem becomes available, if it is a ToolStripMenuItem ' with a CheckOnClick property value of true, subscribe to its ' CheckedChanged event. Protected Overrides Sub OnOwnerChanged(ByVal e As EventArgs) Dim ownerMenuItem As ToolStripMenuItem = _ TryCast(OwnerItem, ToolStripMenuItem) If ownerMenuItem IsNot Nothing AndAlso _ ownerMenuItem.CheckOnClick Then AddHandler ownerMenuItem.CheckedChanged, New _ EventHandler(AddressOf OwnerMenuItem_CheckedChanged) End If MyBase.OnOwnerChanged(e) End Sub
In the handler for the parent-item CheckedChanged event, invalidate the item to update the display with the new enabled state.
// When the checked state of the parent item changes, // repaint the item so that the new Enabled state is displayed. private void OwnerMenuItem_CheckedChanged( object sender, EventArgs e) { Invalidate(); }
' When the checked state of the parent item changes, ' repaint the item so that the new Enabled state is displayed. Private Sub OwnerMenuItem_CheckedChanged( _ ByVal sender As Object, ByVal e As EventArgs) Invalidate() End Sub
Example
The following code example provides the complete ToolStripRadioButtonMenuItem
class, and a Form class and Program
class to demonstrate the option-button behavior.
using System;
using System.Drawing;
using System.Windows.Forms;
using System.Windows.Forms.VisualStyles;
public class ToolStripRadioButtonMenuItem : ToolStripMenuItem
{
public ToolStripRadioButtonMenuItem()
: base()
{
Initialize();
}
public ToolStripRadioButtonMenuItem(string text)
: base(text, null, (EventHandler)null)
{
Initialize();
}
public ToolStripRadioButtonMenuItem(Image image)
: base(null, image, (EventHandler)null)
{
Initialize();
}
public ToolStripRadioButtonMenuItem(string text, Image image)
: base(text, image, (EventHandler)null)
{
Initialize();
}
public ToolStripRadioButtonMenuItem(string text, Image image,
EventHandler onClick)
: base(text, image, onClick)
{
Initialize();
}
public ToolStripRadioButtonMenuItem(string text, Image image,
EventHandler onClick, string name)
: base(text, image, onClick, name)
{
Initialize();
}
public ToolStripRadioButtonMenuItem(string text, Image image,
params ToolStripItem[] dropDownItems)
: base(text, image, dropDownItems)
{
Initialize();
}
public ToolStripRadioButtonMenuItem(string text, Image image,
EventHandler onClick, Keys shortcutKeys)
: base(text, image, onClick)
{
Initialize();
this.ShortcutKeys = shortcutKeys;
}
// Called by all constructors to initialize CheckOnClick.
private void Initialize()
{
CheckOnClick = true;
}
protected override void OnCheckedChanged(EventArgs e)
{
base.OnCheckedChanged(e);
// If this item is no longer in the checked state or if its
// parent has not yet been initialized, do nothing.
if (!Checked || this.Parent == null) return;
// Clear the checked state for all siblings.
foreach (ToolStripItem item in Parent.Items)
{
ToolStripRadioButtonMenuItem radioItem =
item as ToolStripRadioButtonMenuItem;
if (radioItem != null && radioItem != this && radioItem.Checked)
{
radioItem.Checked = false;
// Only one item can be selected at a time,
// so there is no need to continue.
return;
}
}
}
protected override void OnClick(EventArgs e)
{
// If the item is already in the checked state, do not call
// the base method, which would toggle the value.
if (Checked) return;
base.OnClick(e);
}
// Let the item paint itself, and then paint the RadioButton
// where the check mark is normally displayed.
protected override void OnPaint(PaintEventArgs e)
{
if (Image != null)
{
// If the client sets the Image property, the selection behavior
// remains unchanged, but the RadioButton is not displayed and the
// selection is indicated only by the selection rectangle.
base.OnPaint(e);
return;
}
else
{
// If the Image property is not set, call the base OnPaint method
// with the CheckState property temporarily cleared to prevent
// the check mark from being painted.
CheckState currentState = this.CheckState;
this.CheckState = CheckState.Unchecked;
base.OnPaint(e);
this.CheckState = currentState;
}
// Determine the correct state of the RadioButton.
RadioButtonState buttonState = RadioButtonState.UncheckedNormal;
if (Enabled)
{
if (mouseDownState)
{
if (Checked) buttonState = RadioButtonState.CheckedPressed;
else buttonState = RadioButtonState.UncheckedPressed;
}
else if (mouseHoverState)
{
if (Checked) buttonState = RadioButtonState.CheckedHot;
else buttonState = RadioButtonState.UncheckedHot;
}
else
{
if (Checked) buttonState = RadioButtonState.CheckedNormal;
}
}
else
{
if (Checked) buttonState = RadioButtonState.CheckedDisabled;
else buttonState = RadioButtonState.UncheckedDisabled;
}
// Calculate the position at which to display the RadioButton.
Int32 offset = (ContentRectangle.Height -
RadioButtonRenderer.GetGlyphSize(
e.Graphics, buttonState).Height) / 2;
Point imageLocation = new Point(
ContentRectangle.Location.X + 4,
ContentRectangle.Location.Y + offset);
// Paint the RadioButton.
RadioButtonRenderer.DrawRadioButton(
e.Graphics, imageLocation, buttonState);
}
private bool mouseHoverState = false;
protected override void OnMouseEnter(EventArgs e)
{
mouseHoverState = true;
// Force the item to repaint with the new RadioButton state.
Invalidate();
base.OnMouseEnter(e);
}
protected override void OnMouseLeave(EventArgs e)
{
mouseHoverState = false;
base.OnMouseLeave(e);
}
private bool mouseDownState = false;
protected override void OnMouseDown(MouseEventArgs e)
{
mouseDownState = true;
// Force the item to repaint with the new RadioButton state.
Invalidate();
base.OnMouseDown(e);
}
protected override void OnMouseUp(MouseEventArgs e)
{
mouseDownState = false;
base.OnMouseUp(e);
}
// Enable the item only if its parent item is in the checked state
// and its Enabled property has not been explicitly set to false.
public override bool Enabled
{
get
{
ToolStripMenuItem ownerMenuItem =
OwnerItem as ToolStripMenuItem;
// Use the base value in design mode to prevent the designer
// from setting the base value to the calculated value.
if (!DesignMode &&
ownerMenuItem != null && ownerMenuItem.CheckOnClick)
{
return base.Enabled && ownerMenuItem.Checked;
}
else
{
return base.Enabled;
}
}
set
{
base.Enabled = value;
}
}
// When OwnerItem becomes available, if it is a ToolStripMenuItem
// with a CheckOnClick property value of true, subscribe to its
// CheckedChanged event.
protected override void OnOwnerChanged(EventArgs e)
{
ToolStripMenuItem ownerMenuItem =
OwnerItem as ToolStripMenuItem;
if (ownerMenuItem != null && ownerMenuItem.CheckOnClick)
{
ownerMenuItem.CheckedChanged +=
new EventHandler(OwnerMenuItem_CheckedChanged);
}
base.OnOwnerChanged(e);
}
// When the checked state of the parent item changes,
// repaint the item so that the new Enabled state is displayed.
private void OwnerMenuItem_CheckedChanged(
object sender, EventArgs e)
{
Invalidate();
}
}
public class Form1 : Form
{
private MenuStrip menuStrip1 = new MenuStrip();
private ToolStripMenuItem mainToolStripMenuItem = new ToolStripMenuItem();
private ToolStripMenuItem toolStripMenuItem1 = new ToolStripMenuItem();
private ToolStripRadioButtonMenuItem toolStripRadioButtonMenuItem1 =
new ToolStripRadioButtonMenuItem();
private ToolStripRadioButtonMenuItem toolStripRadioButtonMenuItem2 =
new ToolStripRadioButtonMenuItem();
private ToolStripRadioButtonMenuItem toolStripRadioButtonMenuItem3 =
new ToolStripRadioButtonMenuItem();
private ToolStripRadioButtonMenuItem toolStripRadioButtonMenuItem4 =
new ToolStripRadioButtonMenuItem();
private ToolStripRadioButtonMenuItem toolStripRadioButtonMenuItem5 =
new ToolStripRadioButtonMenuItem();
private ToolStripRadioButtonMenuItem toolStripRadioButtonMenuItem6 =
new ToolStripRadioButtonMenuItem();
public Form1()
{
mainToolStripMenuItem.Text = "main";
toolStripRadioButtonMenuItem1.Text = "option 1";
toolStripRadioButtonMenuItem2.Text = "option 2";
toolStripRadioButtonMenuItem3.Text = "option 2-1";
toolStripRadioButtonMenuItem4.Text = "option 2-2";
toolStripRadioButtonMenuItem5.Text = "option 3-1";
toolStripRadioButtonMenuItem6.Text = "option 3-2";
toolStripMenuItem1.Text = "toggle";
toolStripMenuItem1.CheckOnClick = true;
mainToolStripMenuItem.DropDownItems.AddRange(new ToolStripItem[] {
toolStripRadioButtonMenuItem1, toolStripRadioButtonMenuItem2,
toolStripMenuItem1});
toolStripRadioButtonMenuItem2.DropDownItems.AddRange(
new ToolStripItem[] {toolStripRadioButtonMenuItem3,
toolStripRadioButtonMenuItem4});
toolStripMenuItem1.DropDownItems.AddRange(new ToolStripItem[] {
toolStripRadioButtonMenuItem5, toolStripRadioButtonMenuItem6});
menuStrip1.Items.AddRange(new ToolStripItem[] {mainToolStripMenuItem});
Controls.Add(menuStrip1);
MainMenuStrip = menuStrip1;
Text = "ToolStripRadioButtonMenuItem demo";
}
}
static class Program
{
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());
}
}
Imports System.Drawing
Imports System.Windows.Forms
Imports System.Windows.Forms.VisualStyles
Public Class ToolStripRadioButtonMenuItem
Inherits ToolStripMenuItem
Public Sub New()
MyBase.New()
Initialize()
End Sub
Public Sub New(ByVal text As String)
MyBase.New(text, Nothing, CType(Nothing, EventHandler))
Initialize()
End Sub
Public Sub New(ByVal image As Image)
MyBase.New(Nothing, image, CType(Nothing, EventHandler))
Initialize()
End Sub
Public Sub New(ByVal text As String, ByVal image As Image)
MyBase.New(text, image, CType(Nothing, EventHandler))
Initialize()
End Sub
Public Sub New(ByVal text As String, _
ByVal image As Image, ByVal onClick As EventHandler)
MyBase.New(text, image, onClick)
Initialize()
End Sub
Public Sub New(ByVal text As String, ByVal image As Image, _
ByVal onClick As EventHandler, ByVal name As String)
MyBase.New(text, image, onClick, name)
Initialize()
End Sub
Public Sub New(ByVal text As String, ByVal image As Image, _
ByVal ParamArray dropDownItems() As ToolStripItem)
MyBase.New(text, image, dropDownItems)
Initialize()
End Sub
Public Sub New(ByVal text As String, ByVal image As Image, _
ByVal onClick As EventHandler, ByVal shortcutKeys As Keys)
MyBase.New(text, image, onClick)
Initialize()
Me.ShortcutKeys = shortcutKeys
End Sub
' Called by all constructors to initialize CheckOnClick.
Private Sub Initialize()
CheckOnClick = True
End Sub
Protected Overrides Sub OnCheckedChanged(ByVal e As EventArgs)
MyBase.OnCheckedChanged(e)
' If this item is no longer in the checked state or if its
' parent has not yet been initialized, do nothing.
If Not Checked OrElse Me.Parent Is Nothing Then Return
' Clear the checked state for all siblings.
For Each item As ToolStripItem In Parent.Items
Dim radioItem As ToolStripRadioButtonMenuItem = _
TryCast(item, ToolStripRadioButtonMenuItem)
If radioItem IsNot Nothing AndAlso _
radioItem IsNot Me AndAlso _
radioItem.Checked Then
radioItem.Checked = False
' Only one item can be selected at a time,
' so there is no need to continue.
Return
End If
Next
End Sub
Protected Overrides Sub OnClick(ByVal e As EventArgs)
' If the item is already in the checked state, do not call
' the base method, which would toggle the value.
If Checked Then Return
MyBase.OnClick(e)
End Sub
' Let the item paint itself, and then paint the RadioButton
' where the check mark is normally displayed.
Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs)
If Image IsNot Nothing Then
' If the client sets the Image property, the selection behavior
' remains unchanged, but the RadioButton is not displayed and the
' selection is indicated only by the selection rectangle.
MyBase.OnPaint(e)
Return
Else
' If the Image property is not set, call the base OnPaint method
' with the CheckState property temporarily cleared to prevent
' the check mark from being painted.
Dim currentState As CheckState = Me.CheckState
Me.CheckState = CheckState.Unchecked
MyBase.OnPaint(e)
Me.CheckState = currentState
End If
' Determine the correct state of the RadioButton.
Dim buttonState As RadioButtonState = RadioButtonState.UncheckedNormal
If Enabled Then
If mouseDownState Then
If Checked Then
buttonState = RadioButtonState.CheckedPressed
Else
buttonState = RadioButtonState.UncheckedPressed
End If
ElseIf mouseHoverState Then
If Checked Then
buttonState = RadioButtonState.CheckedHot
Else
buttonState = RadioButtonState.UncheckedHot
End If
Else
If Checked Then buttonState = RadioButtonState.CheckedNormal
End If
Else
If Checked Then
buttonState = RadioButtonState.CheckedDisabled
Else
buttonState = RadioButtonState.UncheckedDisabled
End If
End If
' Calculate the position at which to display the RadioButton.
Dim offset As Int32 = CInt((ContentRectangle.Height - _
RadioButtonRenderer.GetGlyphSize( _
e.Graphics, buttonState).Height) / 2)
Dim imageLocation As Point = New Point( _
ContentRectangle.Location.X + 4, _
ContentRectangle.Location.Y + offset)
' Paint the RadioButton.
RadioButtonRenderer.DrawRadioButton( _
e.Graphics, imageLocation, buttonState)
End Sub
Private mouseHoverState As Boolean = False
Protected Overrides Sub OnMouseEnter(ByVal e As EventArgs)
mouseHoverState = True
' Force the item to repaint with the new RadioButton state.
Invalidate()
MyBase.OnMouseEnter(e)
End Sub
Protected Overrides Sub OnMouseLeave(ByVal e As EventArgs)
mouseHoverState = False
MyBase.OnMouseLeave(e)
End Sub
Private mouseDownState As Boolean = False
Protected Overrides Sub OnMouseDown(ByVal e As MouseEventArgs)
mouseDownState = True
' Force the item to repaint with the new RadioButton state.
Invalidate()
MyBase.OnMouseDown(e)
End Sub
Protected Overrides Sub OnMouseUp(ByVal e As MouseEventArgs)
mouseDownState = False
MyBase.OnMouseUp(e)
End Sub
' Enable the item only if its parent item is in the checked state
' and its Enabled property has not been explicitly set to false.
Public Overrides Property Enabled() As Boolean
Get
Dim ownerMenuItem As ToolStripMenuItem = _
TryCast(OwnerItem, ToolStripMenuItem)
' Use the base value in design mode to prevent the designer
' from setting the base value to the calculated value.
If Not DesignMode AndAlso ownerMenuItem IsNot Nothing AndAlso _
ownerMenuItem.CheckOnClick Then
Return MyBase.Enabled AndAlso ownerMenuItem.Checked
Else
Return MyBase.Enabled
End If
End Get
Set(ByVal value As Boolean)
MyBase.Enabled = value
End Set
End Property
' When OwnerItem becomes available, if it is a ToolStripMenuItem
' with a CheckOnClick property value of true, subscribe to its
' CheckedChanged event.
Protected Overrides Sub OnOwnerChanged(ByVal e As EventArgs)
Dim ownerMenuItem As ToolStripMenuItem = _
TryCast(OwnerItem, ToolStripMenuItem)
If ownerMenuItem IsNot Nothing AndAlso _
ownerMenuItem.CheckOnClick Then
AddHandler ownerMenuItem.CheckedChanged, New _
EventHandler(AddressOf OwnerMenuItem_CheckedChanged)
End If
MyBase.OnOwnerChanged(e)
End Sub
' When the checked state of the parent item changes,
' repaint the item so that the new Enabled state is displayed.
Private Sub OwnerMenuItem_CheckedChanged( _
ByVal sender As Object, ByVal e As EventArgs)
Invalidate()
End Sub
End Class
Public Class Form1
Inherits Form
Private menuStrip1 As New MenuStrip()
Private mainToolStripMenuItem As New ToolStripMenuItem()
Private toolStripMenuItem1 As New ToolStripMenuItem()
Private toolStripRadioButtonMenuItem1 As New ToolStripRadioButtonMenuItem()
Private toolStripRadioButtonMenuItem2 As New ToolStripRadioButtonMenuItem()
Private toolStripRadioButtonMenuItem3 As New ToolStripRadioButtonMenuItem()
Private toolStripRadioButtonMenuItem4 As New ToolStripRadioButtonMenuItem()
Private toolStripRadioButtonMenuItem5 As New ToolStripRadioButtonMenuItem()
Private toolStripRadioButtonMenuItem6 As New ToolStripRadioButtonMenuItem()
Public Sub New()
Me.mainToolStripMenuItem.Text = "main"
toolStripRadioButtonMenuItem1.Text = "option 1"
toolStripRadioButtonMenuItem2.Text = "option 2"
toolStripRadioButtonMenuItem3.Text = "option 2-1"
toolStripRadioButtonMenuItem4.Text = "option 2-2"
toolStripRadioButtonMenuItem5.Text = "option 3-1"
toolStripRadioButtonMenuItem6.Text = "option 3-2"
toolStripMenuItem1.Text = "toggle"
toolStripMenuItem1.CheckOnClick = True
mainToolStripMenuItem.DropDownItems.AddRange(New ToolStripItem() { _
toolStripRadioButtonMenuItem1, toolStripRadioButtonMenuItem2, _
toolStripMenuItem1})
toolStripRadioButtonMenuItem2.DropDownItems.AddRange( _
New ToolStripItem() {toolStripRadioButtonMenuItem3, _
toolStripRadioButtonMenuItem4})
toolStripMenuItem1.DropDownItems.AddRange(New ToolStripItem() { _
toolStripRadioButtonMenuItem5, toolStripRadioButtonMenuItem6})
menuStrip1.Items.AddRange(New ToolStripItem() {mainToolStripMenuItem})
Controls.Add(menuStrip1)
MainMenuStrip = menuStrip1
Text = "ToolStripRadioButtonMenuItem demo"
End Sub
End Class
Public Class Program
<STAThread()> Public Shared Sub Main()
Application.EnableVisualStyles()
Application.SetCompatibleTextRenderingDefault(False)
Application.Run(New Form1())
End Sub
End Class
Compiling the Code
This example requires:
- References to the System, System.Drawing, and System.Windows.Forms assemblies.
See also
.NET Desktop feedback