利用SendMessage实现C#进程间通信

1、进程之间通讯的几种方法:在Windows程序中，各个进程之间常常需要交换数据，进行数据通讯。常用的方法有使用内存映射文件通过共享内存DLL共享内存使用SendMessage向另一进程发送WM_COPYDATA消息比起前两种的复杂实现来,WM_COPYDATA消息无疑是一种经济实惠的一中方法.(ZT)WM_COPYDATA消息的主要目的是允许在进程间传递只读数据。Windows在通过WM_COPYDATA消息传递期间，不提供继承同步方式。SDK文档推荐用户使用SendMessage函数，接受方在数据拷贝完成前不返回，这样发送方就不可能删除和修改数据：这个函数的原型及其要用到的结构如下:SendM

2、essage(hwnd,WM_COPYDATA,wParam,lParam);其中,WM_COPYDATA对应的十六进制数为0X004AwParam设置为包含数据的窗口的句柄。IParam指向一个COPYDATASTRUCT的结构:typedefstructtagCOPYDATASTRUCTDWORDdwData;用户定义数据DWORDcbData;数据大小PVOIDIpData;/指向数据的指针COPYDATASTRUCT;该结构用来定义用户数据。具体过程如下:首先，在发送方，用FindWindow找到接受方的句柄，然后向接受方发送WM_COPYDATA消息.接受方在DefWndProc事件

3、中，来处理这条消息.由于中文编码是两个字节，所以传递中文时候字节长度要搞清楚.体代码如下:/发送方:usingSystem;usingSystem.Drawing;usingSystem.CoIIections;usingSystem.ComponentModel;usingSystem.Windows.Forms;usingSystem.Data;usingSystem.Runtime.InteropServices;namespaceWinFormSendMsgpublicclassForm1:System.Windows.Forms.FormprivateSystem.Windows.F

4、orms.TextBoxtextBox1;privateSystem.Windows.Forms.Buttonbutton1;privateSystem.ComponentModel.Containercomponents=null;constintWM_COPYDATA=0 x004A;publicForm1()InitializeComponent();protectedoverridevoidDispose(booldisposing)if(disposing)if(components!=null)components.Dispose();base.Dispose(disposing)

5、;privatevoidInitializeComponent()this.textBox1=newSystem.Windows.Forms.TextBox();this.button1=newSystem.Windows.Forms.Button();this.SuspendLayout();/textBox1/this.textBox1.Location=newSystem.Drawing.Point(184,24);this.textBox1.Name=textBox1;this.textBox1.Size=newSystem.Drawing.Size(128,21);this.text

6、Box1.TabIndex=0;this.textBox1.Text=textBox1;/button1/this.button1.Location=newSystem.Drawing.Point(344,16);this.button1.Name=button1;this.button1.Size=newSystem.Drawing.Size(112,32);this.button1.TabIndex=1;this.button1.Text=button1;this.button1.Click+=newSystem.EventHandler(this.button1_Click);/Form

7、1/this.AutoScaleBaseSize=newSystem.Drawing.Size(6,14);this.ClientSize=newSystem.Drawing.Size(536,142);this.Controls.AddRange(newSystem.Windows.Forms.Controlthis.button1,this.textBox1);this.Name=Form1;this.Text=发送方窗体;this.ResumeLayout(false);staticvoidMain()Application.Run(newForm1();DllImport(User32

8、.dll,EntryPoint=SendMessage)privatestaticexternintSendMessage(inthWnd,/handletodestinationwindowintMsg,/messageintwParam,/firstmessageparameterrefCOPYDATASTRUCTlParam/secondmessageparameter);DllImport(User32.dll,EntryPoint=FindWindow)privatestaticexternintFindWindow(stringlpClassName,stringlpWindowN

9、ame);privatevoidbutton1_Click(objectsender,System.EventArgse)intWINDOW_HANDLER=FindWindow(null,接收方窗体);if(WINDOW_HANDLER=0)elsebytesarr=System.Text.Encoding.Default.GetBytes(this.textBox1.Text);intlen=sarr.Length;COPYDATASTRUCTcds;cds.dwData=(IntPtr)100;cds.lpData=this.textBox1.Text;cds.cbData=len+1;

10、SendMessage(WINDOW_HANDLER,WM_COPYDATA,0,refcds);publicstructCOPYDATASTRUCTpublicIntPtrdwData;publicintcbData;MarshalAs(UnmanagedType.LPStr)publicstringlpData;/接受方/usingSystem;usingSystem.Drawing;usingSystem.Collections;usingSystem.ComponentModel;usingSystem.Windows.Forms;usingSystem.Data;usingSyste

11、m.Runtime.InteropServices;namespaceWindowsFormGetMsgpublicclassForm1:System.Windows.Forms.FormprivateSystem.Windows.Forms.TextBoxtextBox1;privateSystem.ComponentModel.Containercomponents=null;constintWM_COPYDATA=0 x004A;publicForm1()InitializeComponent();protectedoverridevoidDispose(booldisposing)if

12、(disposing)if(components!=null)components.Dispose();base.Dispose(disposing);privatevoidInitializeComponent()this.textBox1=newSystem.Windows.Forms.TextBox();this.SuspendLayout();/textBox1/this.textBox1.Location=newSystem.Drawing.Point(176,32);this.textBox1.Name=textBox1;this.textBox1.Size=newSystem.D

13、rawing.Size(160,21);this.textBox1.TabIndex=0;this.textBox1.Text=textBox1;/Form1/this.AutoScaleBaseSize=newSystem.Drawing.Size(6,14);this.ClientSize=newSystem.Drawing.Size(432,266);this.Controls.AddRange(newSystem.Windows.Forms.Controlthis.textBox1);this.Name=Form1;this.Text=接收方窗体;this.ResumeLayout(false);staticvoidMain()Application.Run(newForm1();protectedoverridevoidDefWndProc(refSystem.Windows.Forms.Messagem)switch(m.Msg)caseWM_COPYDATA:COPYDATASTRUCTmystr=newCOPYDATASTRUCT();Typemytype=mystr.GetType();mystr=(COP