ToolStripRenderer.OnRenderToolStripBackground Method

Definition

Namespace:

System.Windows.Forms

Assembly:

System.Windows.Forms.dll

Source:

ToolStripRenderer.cs

Raises the RenderToolStripBackground event.

C#

protected virtual void OnRenderToolStripBackground(System.Windows.Forms.ToolStripRenderEventArgs e);

Parameters

e

ToolStripRenderEventArgs

A ToolStripRenderEventArgs that contains the event data.

Examples

The following code example demonstrates how to override the OnRenderToolStripBackground method to paint a gradient in the background of a ToolStrip control. This code example is part of a larger example provided for the ToolStripRenderer class.

C#

// This method renders the GridStrip control's background.
protected override void OnRenderToolStripBackground(
    ToolStripRenderEventArgs e)
{
    base.OnRenderToolStripBackground(e);

    // This late initialization is a workaround. The gradient
    // depends on the bounds of the GridStrip control. The bounds 
    // are dependent on the layout engine, which hasn't fully
    // performed layout by the time the Initialize method runs.
    if (this.backgroundBrush == null)
    {
        this.backgroundBrush = new LinearGradientBrush(
           e.ToolStrip.ClientRectangle,
           SystemColors.ControlLightLight,
           SystemColors.ControlDark,
           90,
           true);
    }

    // Paint the GridStrip control's background.
    e.Graphics.FillRectangle(
        this.backgroundBrush, 
        e.AffectedBounds);
}

Remarks

Raising an event invokes the event handler through a delegate. For more information, see Handling and Raising Events.

The OnRenderToolStripBackground method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

Notes to Inheritors

When overriding OnRenderToolStripBackground(ToolStripRenderEventArgs) in a derived class, be sure to call the base class's OnRenderToolStripBackground(ToolStripRenderEventArgs) method so that registered delegates receive the event.

Applies to

See also

• How to: Implement a Custom ToolStripRenderer