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OnPaint Method

Summary

Overrides System.Windows.Forms.Control.OnPaint(System.Windows.Forms.PaintEventArgs).

Syntax

C++/CLI

C++

protected override void OnPaint( 
   PaintEventArgs e 
)

protected: 
void OnPaint(  
   PaintEventArgs^ e 
) override

protected:  
   virtual void OnPaint( 
      PaintEventArgs^ e 
   ) override

Parameters

e
A System.Windows.Forms.PaintEventArgs that contains information about the control to paint.

Remarks

Raising an event invokes the event handler through a delegate.

The OnPaint 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 OnPaint in a derived class, be sure to call the base class's OnPaint method so that registered delegates receive the event.

Example

This example overrides the virtual events of the RasterImagePanViewer class.

using Leadtools.WinForms; 
using Leadtools; 
using Leadtools.Codecs; 
 
public class MyRasterImagePanViewer : RasterImagePanViewer 
{ 
   //. 
   //. 
   //. 
   protected override void OnViewerChanged(EventArgs e) 
   { 
      base.OnViewerChanged(e); 
 
      Console.WriteLine("OnViewerChanged is called"); 
   } 
 
   protected override void OnRectangleColorChanged(EventArgs e) 
   { 
      base.OnRectangleColorChanged(e); 
 
      Console.WriteLine("OnRectangleColorChanged is called"); 
   } 
 
   protected override void OnImageColorChanged(EventArgs e) 
   { 
      base.OnImageColorChanged(e); 
 
      Console.WriteLine("OnImageColorChanged is called"); 
   } 
 
   protected override void OnClipCursorChanged(EventArgs e) 
   { 
      base.OnClipCursorChanged(e); 
 
      Console.WriteLine("OnClipCursorChanged is called"); 
   } 
 
   protected override void OnPaint(PaintEventArgs e) 
   { 
      base.OnPaint(e); 
 
      Console.WriteLine("OnPaint is called"); 
   } 
 
   protected override void OnMouseDown(MouseEventArgs e) 
   { 
      base.OnMouseDown(e); 
 
      Console.WriteLine("OnMouseDown is called"); 
   } 
 
   protected override void OnMouseMove(MouseEventArgs e) 
   { 
      base.OnMouseMove(e); 
 
      Console.WriteLine("OnMouseMove is called"); 
   } 
 
   protected override void OnMouseUp(MouseEventArgs e) 
   { 
      base.OnMouseUp(e); 
 
      Console.WriteLine("OnMouseUp is called"); 
   } 
 
   protected override void OnLostFocus(EventArgs e) 
   { 
      base.OnLostFocus(e); 
 
      Console.WriteLine("OnLostFocus is called"); 
   } 
 
   protected override void OnSizeChanged(EventArgs e) 
   { 
      base.OnSizeChanged(e); 
 
      Console.WriteLine("OnSizeChanged is called"); 
   } 
}

Requirements

Target Platforms