Provides methods used to render a check box control with or without visual styles. This class cannot be inherited.
Namespace:
System.Windows.Forms
Assembly:
System.Windows.Forms (in System.Windows.Forms.dll)
Visual Basic (Declaration)
Public NotInheritable Class CheckBoxRenderer
Dim instance As CheckBoxRenderer
public sealed class CheckBoxRenderer
public ref class CheckBoxRenderer sealed
public final class CheckBoxRenderer
The CheckBoxRenderer class provides a set of static methods that can be used to render a check box control. Rendering a control refers to drawing the user interface of a control. To draw a check box, use one of the DrawCheckBox methods. These methods provide a variety of options, such as drawing text or an image with the check box.
If visual styles are enabled in the operating system and visual styles are applied to the current application, DrawCheckBox will draw the check box with the current visual style. Otherwise, DrawCheckBox will draw the check box with the classic Windows style. This is useful if you are drawing a custom control that should automatically match the current visual style setting of the operating system.
This class wraps the functionality of a System.Windows.Forms.VisualStyles..::.VisualStyleRenderer that is set to one of the elements exposed by the System.Windows.Forms.VisualStyles..::.VisualStyleElement..::.Button..::.CheckBox class. For more information, see Rendering Controls with Visual Styles.
Windows XP Home Edition, Windows XP Professional x64 Edition, Windows Server 2003 Platform Note:
Visual styles are supported only on these platforms.
The following code example demonstrates how to write a custom control that uses the DrawCheckBox method to draw a check box that responds to mouse clicks.
Imports System
Imports System.Drawing
Imports System.Windows.Forms
Imports System.Windows.Forms.VisualStyles
Namespace CheckBoxRendererSample
Class Form1
Inherits Form
Public Sub New()
Dim CheckBox1 As New CustomCheckBox()
Controls.Add(CheckBox1)
If Application.RenderWithVisualStyles Then
Me.Text = "Visual Styles Enabled"
Else
Me.Text = "Visual Styles Disabled"
End If
End Sub
<STAThread()> _
Shared Sub Main()
' If you do not call EnableVisualStyles below, then
' CheckBoxRenderer.DrawCheckBox automatically detects
' this and draws the check box without visual styles.
Application.EnableVisualStyles()
Application.Run(New Form1())
End Sub
End Class
Public Class CustomCheckBox
Inherits Control
Private textRectangleValue As New Rectangle()
Private clickedLocationValue As New Point()
Private clicked As Boolean = False
Private state As CheckBoxState = CheckBoxState.UncheckedNormal
Public Sub New()
With Me
.Location = New Point(50, 50)
.Size = New Size(100, 20)
.Text = "Click here"
.Font = SystemFonts.IconTitleFont
End With
End Sub
' Calculate the text bounds, exluding the check box.
Public ReadOnly Property TextRectangle() As Rectangle
Get
Using g As Graphics = Me.CreateGraphics()
With textRectangleValue
.X = Me.ClientRectangle.X + _
CheckBoxRenderer.GetGlyphSize(g, _
CheckBoxState.UncheckedNormal).Width
.Y = Me.ClientRectangle.Y
.Width = Me.ClientRectangle.Width - _
CheckBoxRenderer.GetGlyphSize(g, _
CheckBoxState.UncheckedNormal).Width
.Height = Me.ClientRectangle.Height
End With
End Using
Return textRectangleValue
End Get
End Property
' Draw the check box in the current state.
Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs)
MyBase.OnPaint(e)
CheckBoxRenderer.DrawCheckBox(e.Graphics, _
Me.ClientRectangle.Location, TextRectangle, Me.Text, _
Me.Font, TextFormatFlags.HorizontalCenter, _
clicked, state)
End Sub
' Draw the check box in the checked or unchecked state, alternately.
Protected Overrides Sub OnMouseDown(ByVal e As MouseEventArgs)
MyBase.OnMouseDown(e)
If Not clicked Then
With Me
.clicked = True
.Text = "Clicked!"
.state = CheckBoxState.CheckedPressed
End With
Invalidate()
Else
With Me
.clicked = False
.Text = "Click here"
.state = CheckBoxState.UncheckedNormal
End With
Invalidate()
End If
End Sub
' Draw the check box in the hot state.
Protected Overrides Sub OnMouseHover(ByVal e As EventArgs)
MyBase.OnMouseHover(e)
If clicked Then
state = CheckBoxState.CheckedHot
Else
state = CheckBoxState.UncheckedHot
End If
Invalidate()
End Sub
' Draw the check box in the hot state.
Protected Overrides Sub OnMouseUp(ByVal e As MouseEventArgs)
MyBase.OnMouseUp(e)
Me.OnMouseHover(e)
End Sub
' Draw the check box in the unpressed state.
Protected Overrides Sub OnMouseLeave(ByVal e As EventArgs)
MyBase.OnMouseLeave(e)
If clicked Then
state = CheckBoxState.CheckedNormal
Else
state = CheckBoxState.UncheckedNormal
End If
Invalidate()
End Sub
End Class
End Namespace
using System;
using System.Drawing;
using System.Windows.Forms;
using System.Windows.Forms.VisualStyles;
namespace CheckBoxRendererSample
{
class Form1 : Form
{
public Form1()
: base()
{
CustomCheckBox CheckBox1 = new CustomCheckBox();
Controls.Add(CheckBox1);
if (Application.RenderWithVisualStyles)
this.Text = "Visual Styles Enabled";
else
this.Text = "Visual Styles Disabled";
}
[STAThread]
static void Main()
{
// If you do not call EnableVisualStyles below, then
// CheckBoxRenderer.DrawCheckBox automatically detects
// this and draws the check box without visual styles.
Application.EnableVisualStyles();
Application.Run(new Form1());
}
}
public class CustomCheckBox : Control
{
private Rectangle textRectangleValue = new Rectangle();
private Point clickedLocationValue = new Point();
private bool clicked = false;
private CheckBoxState state = CheckBoxState.UncheckedNormal;
public CustomCheckBox()
: base()
{
this.Location = new Point(50, 50);
this.Size = new Size(100, 20);
this.Text = "Click here";
this.Font = SystemFonts.IconTitleFont;
}
// Calculate the text bounds, exluding the check box.
public Rectangle TextRectangle
{
get
{
using (Graphics g = this.CreateGraphics())
{
textRectangleValue.X = ClientRectangle.X +
CheckBoxRenderer.GetGlyphSize(g,
CheckBoxState.UncheckedNormal).Width;
textRectangleValue.Y = ClientRectangle.Y;
textRectangleValue.Width = ClientRectangle.Width -
CheckBoxRenderer.GetGlyphSize(g,
CheckBoxState.UncheckedNormal).Width;
textRectangleValue.Height = ClientRectangle.Height;
}
return textRectangleValue;
}
}
// Draw the check box in the current state.
protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
CheckBoxRenderer.DrawCheckBox(e.Graphics,
ClientRectangle.Location, TextRectangle, this.Text,
this.Font, TextFormatFlags.HorizontalCenter,
clicked, state);
}
// Draw the check box in the checked or unchecked state, alternately.
protected override void OnMouseDown(MouseEventArgs e)
{
base.OnMouseDown(e);
if (!clicked)
{
clicked = true;
this.Text = "Clicked!";
state = CheckBoxState.CheckedPressed;
Invalidate();
}
else
{
clicked = false;
this.Text = "Click here";
state = CheckBoxState.UncheckedNormal;
Invalidate();
}
}
// Draw the check box in the hot state.
protected override void OnMouseHover(EventArgs e)
{
base.OnMouseHover(e);
state = clicked ? CheckBoxState.CheckedHot :
CheckBoxState.UncheckedHot;
Invalidate();
}
// Draw the check box in the hot state.
protected override void OnMouseUp(MouseEventArgs e)
{
base.OnMouseUp(e);
this.OnMouseHover(e);
}
// Draw the check box in the unpressed state.
protected override void OnMouseLeave(EventArgs e)
{
base.OnMouseLeave(e);
state = clicked ? CheckBoxState.CheckedNormal :
CheckBoxState.UncheckedNormal;
Invalidate();
}
}
}
#using <System.dll>
#using <System.Drawing.dll>
#using <System.Windows.Forms.dll>
using namespace System;
using namespace System::Drawing;
using namespace System::Windows::Forms;
using namespace System::Windows::Forms::VisualStyles;
namespace ComboBoxRendererSample
{
ref class CustomComboBox: public Control
{
private:
System::Drawing::Size arrowSize;
Rectangle arrowRectangle;
Rectangle topTextBoxRectangle;
Rectangle bottomTextBoxRectangle;
ComboBoxState textBoxState;
ComboBoxState arrowState;
String^ bottomText;
bool isActivated;
int minHeight;
int minWidth;
public:
CustomComboBox() : Control()
{
minHeight = 38;
minWidth = 40;
this->Location = Point(10, 10);
this->Size = System::Drawing::Size(140, 38);
this->Font = SystemFonts::IconTitleFont;
this->Text = "Click the button";
textBoxState = ComboBoxState::Normal;
bottomText = "Using ComboBoxRenderer";
arrowState = ComboBoxState::Normal;
// Initialize the rectangles to look like the standard combo
// box control.
arrowSize = System::Drawing::Size(18, 20);
arrowRectangle = Rectangle(ClientRectangle.X +
ClientRectangle.Width - arrowSize.Width - 1,
ClientRectangle.Y + 1,
arrowSize.Width,
arrowSize.Height);
topTextBoxRectangle = Rectangle(ClientRectangle.X,
ClientRectangle.Y,
ClientRectangle.Width,
arrowSize.Height + 2);
bottomTextBoxRectangle = Rectangle(ClientRectangle.X,
ClientRectangle.Y + topTextBoxRectangle.Height,
ClientRectangle.Width,
topTextBoxRectangle.Height - 6);
}
// Draw the combo box in the current state.
protected:
virtual void OnPaint(PaintEventArgs^ e) override
{
Control::OnPaint(e);
if (!ComboBoxRenderer::IsSupported)
{
this->Parent->Text = "Visual Styles Disabled";
return;
}
this->Parent->Text = "CustomComboBox Enabled";
// Always draw the main text box and drop down arrow in their
// current states
ComboBoxRenderer::DrawTextBox(e->Graphics, topTextBoxRectangle,
this->Text, this->Font, textBoxState);
ComboBoxRenderer::DrawDropDownButton(e->Graphics, arrowRectangle,
arrowState);
// Only draw the bottom text box if the arrow has been clicked
if (isActivated)
{
ComboBoxRenderer::DrawTextBox(e->Graphics,
bottomTextBoxRectangle, bottomText, this->Font,
textBoxState);
}
}
protected:
virtual void OnMouseDown(MouseEventArgs^ e) override
{
Control::OnMouseDown(e);
// Check whether the user clicked the arrow.
if (arrowRectangle.Contains(e->Location) &&
ComboBoxRenderer::IsSupported)
{
// Draw the arrow in the pressed state.
arrowState = ComboBoxState::Pressed;
// The user has activated the combo box.
if (!isActivated)
{
this->Text = "Clicked!";
textBoxState = ComboBoxState::Pressed;
isActivated = true;
}
// The user has deactivated the combo box.
else
{
this->Text = "Click here";
textBoxState = ComboBoxState::Normal;
isActivated = false;
}
// Redraw the control.
Invalidate();
}
}
protected:
virtual void OnMouseUp(MouseEventArgs^ e) override
{
Control::OnMouseUp(e);
if (arrowRectangle.Contains(e->Location) &&
ComboBoxRenderer::IsSupported)
{
arrowState = ComboBoxState::Normal;
Invalidate();
}
}
};
ref class Form1 : public Form
{
public:
Form1() : Form()
{
this->Size = System::Drawing::Size(300, 300);
CustomComboBox^ ComboBox1 = gcnew CustomComboBox();
Controls->Add(ComboBox1);
}
};
}
[STAThread]
int main()
{
// The call to EnableVisualStyles below does not affect
// whether ComboBoxRenderer.IsSupported is true; as long as visual
// styles are enabled by the operating system, IsSupported is true.
Application::EnableVisualStyles();
Application::Run(gcnew ComboBoxRendererSample::Form1());
}
System..::.Object
System.Windows.Forms..::.CheckBoxRenderer
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
.NET Framework
Supported in: 3.5, 3.0, 2.0
Reference