重写WndProc方法来处理 Windows 消息

处理 Windows 消息。
在开发winForm时，常常要处理Windows消息，可以重写WndProc来实现。常见代码如下：

using System;
using System.Drawing;
using System.Windows.Forms;

namespace csTempWindowsApplication1
{
public class Form1 : System.Windows.Forms.Form
{
// Constant value was found in the "windows.h" header file.
private const int WM_LBUTTONDBLCLK== 0x203;//双击左键

[System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name="FullTrust")]
protected override void WndProc(ref Message m)
{
// Listen for operating system messages.
switch (m.Msg)
{
// The WM_ACTIVATEAPP message occurs when the application
// becomes the active application or becomes inactive.
case WM_LBUTTONDBLCLK:

MessageBox.Show("双击了左键");
break;
}
base.WndProc(ref m);
}
}
}