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DrawItemEventHandler Delegate

Represents the method that will handle the DrawItem event of a ComboBox, ListBox, MenuItem, or TabControl control.

Namespace: System.Windows.Forms
Assembly: System.Windows.Forms (in system.windows.forms.dll)

public delegate void DrawItemEventHandler (
	Object sender,
	DrawItemEventArgs e
)
/** @delegate */
public delegate void DrawItemEventHandler (
	Object sender, 
	DrawItemEventArgs e
)
JScript supports the use of delegates, but not the declaration of new ones.

Parameters

sender

The source of the event.

e

A DrawItemEventArgs that contains the event data.

When you create a DrawItemEventArgs delegate, you identify the method that will handle the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. For more information about event handler delegates, see Events and Delegates.

The following code example demonstrates a menu with an owner-drawn menu item. This example uses the AddHandler statement and the AddressOf operator to designate a delegate to handle the MenuItem.DrawItem event. To run the example place paste it in a form that imports the System, System.Windows.Forms, and System.Drawing namespaces. Ensure all events are associated with their event-handling methods.

// Declare the MainMenu control.
internal System.Windows.Forms.MainMenu MainMenu1;

// Declare MenuItem2 as With-Events because it will be user drawn.
internal System.Windows.Forms.MenuItem MenuItem2;


private void InitializeMenu()
{

    // Create MenuItem1, which will be drawn by the operating system.
    MenuItem MenuItem1 = new MenuItem("Regular Menu Item");

    // Create MenuItem2.
    MenuItem2 = new MenuItem("Custom Menu Item");

    // Set OwnerDraw property to true. This requires handling the
    // DrawItem event for this menu item.
    MenuItem2.OwnerDraw = true;

    //Add the event-handler delegate to handle the DrawItem event.
    MenuItem2.DrawItem += new DrawItemEventHandler(DrawCustomMenuItem);
    
  // Add the items to the menu.
    MainMenu1 = new MainMenu(new MenuItem[]{MenuItem1, MenuItem2});                                                                                                                      

    // Add the menu to the form.
    this.Menu = this.MainMenu1;
}

// Draw the custom menu item.
private void DrawCustomMenuItem(object sender, 
    DrawItemEventArgs e)
{

    // Cast the sender to MenuItem so you can access text property.
    MenuItem customItem = (MenuItem) sender;

    // Create a Brush and a Font to draw the MenuItem.
    System.Drawing.Brush aBrush = System.Drawing.Brushes.DarkMagenta;
    Font aFont = new Font("Garamond", 10, 
        FontStyle.Italic, GraphicsUnit.Point);

    // Get the size of the text to use later to draw an ellipse
    // around the item.
    SizeF stringSize = e.Graphics.MeasureString(
        customItem.Text, aFont);

    // Draw the item and then draw the ellipse.
    e.Graphics.DrawString(customItem.Text, aFont, 
        aBrush, e.Bounds.X, e.Bounds.Y);
    e.Graphics.DrawEllipse(new Pen(System.Drawing.Color.Black, 2),
        new Rectangle(e.Bounds.X, e.Bounds.Y, 
        (System.Int32)stringSize.Width,
        (System.Int32)stringSize.Height));
}

// Declare the MainMenu control.
System.Windows.Forms.MainMenu mainMenu1;

// Declare MenuItem2 as With-Events because it will be user drawn.
System.Windows.Forms.MenuItem menuItem2;

private void InitializeMenu()
{
    // Create MenuItem1, which will be drawn by the operating system.
    MenuItem menuItem1 = new MenuItem("Regular Menu Item");
    // Create MenuItem2.
    menuItem2 = new MenuItem("Custom Menu Item");
    // Set OwnerDraw property to true. This requires handling the
    // DrawItem event for this menu item.
    menuItem2.set_OwnerDraw(true);
    //Add the event-handler delegate to handle the DrawItem event.
    menuItem2.add_DrawItem(new DrawItemEventHandler(DrawCustomMenuItem));
    // Add the items to the menu.
    mainMenu1 = new MainMenu(new MenuItem[] { menuItem1, menuItem2 });
    // Add the menu to the form.
    this.set_Menu(this.mainMenu1);
} //InitializeMenu

// Draw the custom menu item.
private void DrawCustomMenuItem(Object sender, DrawItemEventArgs e)
{
    // Cast the sender to MenuItem so you can access text property.
    MenuItem customItem = (MenuItem)sender;
    // Create a Brush and a Font to draw the MenuItem.
    System.Drawing.Brush aBrush = System.Drawing.Brushes.get_DarkMagenta();
    Font aFont =
        new Font("Garamond", 10, FontStyle.Italic, GraphicsUnit.Point);
    // Get the size of the text to use later to draw an ellipse
    // around the item.
    SizeF stringSize =
        e.get_Graphics().MeasureString(customItem.get_Text(), aFont);
    // Draw the item and then draw the ellipse.
    e.get_Graphics().
        DrawString(customItem.get_Text(), aFont, aBrush,
        e.get_Bounds().get_X(), e.get_Bounds().get_Y());
    e.get_Graphics().
        DrawEllipse(new Pen(System.Drawing.Color.get_Black(), 2),
        new Rectangle(e.get_Bounds().get_X(), e.get_Bounds().get_Y(),
        System.Convert.ToInt32((System.Int32)stringSize.get_Width()),
        System.Convert.ToInt32((System.Int32)stringSize.get_Height())));
} //DrawCustomMenuItem

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0
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