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OnViewerChanged Method

Summary

Syntax

C++/CLI

C++

protected virtual void OnViewerChanged( 
   EventArgs e 
)

protected: 
virtual void OnViewerChanged(  
   EventArgs^ e 
)

protected:  
   virtual void OnViewerChanged( 
      EventArgs^ e 
   )

Parameters

e
An System.EventArgs that contains the event data.

Remarks

Raising an event invokes the event handler through a delegate. The OnViewerChanged 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 OnViewerChanged in a derived class, be sure to call the base class's OnViewerChanged 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