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CheckBoxRenderer Class

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)

public ref class CheckBoxRenderer sealed

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.

#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

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