ToolStripRenderer.OnRenderToolStripBackground Method

Reference

Definition

Namespace:: System.Windows.Forms

Assembly:: System.Windows.Forms.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Raises the RenderToolStripBackground event.

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

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

abstract member OnRenderToolStripBackground : System.Windows.Forms.ToolStripRenderEventArgs -> unit
override this.OnRenderToolStripBackground : System.Windows.Forms.ToolStripRenderEventArgs -> unit

Protected Overridable Sub OnRenderToolStripBackground (e As ToolStripRenderEventArgs)

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.

// 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);
}

' This method renders the GridStrip control's background.
Protected Overrides Sub OnRenderToolStripBackground(e As ToolStripRenderEventArgs)
   MyBase.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 Me.backgroundBrush Is Nothing Then
      Me.backgroundBrush = New LinearGradientBrush(e.ToolStrip.ClientRectangle, SystemColors.ControlLightLight, SystemColors.ControlDark, 90, True)
   End If
   
   ' Paint the GridStrip control's background.
   e.Graphics.FillRectangle(Me.backgroundBrush, e.AffectedBounds)
  End Sub

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

Del via