Junstyle's Blog

窗体1中的代码：

	/////////////////////////////////////////
	///file name: Note.cs
	///
	public class Note
	{
		//声明 API 函数
		[DllImport( "User32.dll", EntryPoint = "SendMessage" )]
		private static extern int SendMessage(
			  int hWnd,     // handle to destination window
			  int Msg,     // message
			  int wParam,   // first message parameter
			  int lParam   // second message parameter
		);
		[DllImport( "User32.dll", EntryPoint = "FindWindow" )]
		private static extern int FindWindow( string lpClassName, string lpWindowName );
		//定义消息常数
		public const int USER = 0x500;
		public const int TEST = USER + 1;

		//向窗体发送消息的函数
		private void SendMsgToMainForm( int MSG )
		{
			int WINDOW_HANDLER = FindWindow( null, @"Note Pad" );
			if( WINDOW_HANDLER == 0 )
			{
				throw new Exception( "Could not find Main window!" );
			}
			SendMessage( WINDOW_HANDLER, MSG, 100, 200 );
		}
	}

窗体2中的代码

	/////////////////////////////////////////
	/// File name : Form1.cs
	/// 接收消息的窗体
	///
	public class Form1 : System.Windows.Forms.Form
	{
		public Form1()
		{
			//
			// Required for Windows Form Designer support
			//
			InitializeComponent();
			//
			// TODO: Add any constructor code after InitializeComponent call
			//
		}
		/// 重写窗体的消息处理函数
		protected override void DefWndProc( ref System.Windows.Forms.Message m )
		{
			switch( m.Msg )
			{
				//接收自定义消息 USER，并显示其参数
				case Note.USER:
					string message = string.Format( "Received message! parameters are :{0},{1}", m.WParam, m.LParam );
					MessageBox.Show( message );
					break;
				default:
					base.DefWndProc( ref m );
					break;
			}
			//Console.WriteLine(m.LParam);
		}
	}