ToolStripRenderer.OnRenderToolStripBackground Method

Reference

Definition

Namespace:: System.Windows.Forms

Assembly:: System.Windows.Forms.dll

Important

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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

Dela via