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Providing a Toolbox Bitmap for Your Control

You might want to have a special icon for your control appear in the Toolbox. You can specify a particular image by using the ToolboxBitmapAttribute Class. This class is an attribute, a special kind of class you can attach to other classes. For more information on attributes, see Attributes Overview for Visual Basic and Introduction to Attributes for C#.

Using the ToolboxBitmapAttribute, you can specify a String that indicates the path and file name for a 16 by 16 pixel bitmap. This bitmap then appears next to your control when added to the Toolbox. You can also specify a Type, in which case the bitmap associated with that type is loaded. If you specify both a Type and a String, the control searches for an image resource with the name specified by the String parameter in the assembly containing the type specified by the Type parameter.

To specify a Toolbox bitmap for your control

  • Add the ToolBoxBitmapAttribute to the class declaration of your control before the Class keyword for Visual Basic, and above the class declaration for Visual C#.
    ' Visual Basic
    ' Specifies the bitmap associated with the Button type.
    <ToolboxBitmap(GetType(Button))> Class MyControl1
    ' Specifies a bitmap file.
    End Class
    <ToolboxBitmap("C:\Documents and Settings\Joe\MyPics\myImage.bmp")> _
       Class MyControl2
    End Class
    ' Specifies a type that indicates the assembly to search, and the name 
    ' of an image resource to look for.
    <ToolboxBitmap(GetType(MyControl), "MyControlBitmap")> Class MyControl
    End Class
    
    // C#
    // Specifies the bitmap associated with the Button type.
    [ToolboxBitmap(typeof(Button))]
    class MyControl1 : UserControl
    {
    }
    // Specifies a bitmap file.
    [ToolboxBitmap(@"C:\Documents and Settings\Joe\MyPics\myImage.bmp")]
    class MyControl2 : UserControl
    {
    }
    // Specifies a type that indicates the assembly to search, and the name 
    // of an image resource to look for.
    [ToolboxBitmap(typeof(MyControl), "MyControlBitmap")]
    class MyControl : UserControl
    {
    }
    

See Also

Control Authoring for Windows Forms | Visual Basic .NET Attributes | Introduction to Attributes

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