C#进程通信

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:

SendMessage(hwnd,WM_COPYDATA,wParam,lParam);

其中,WM_COPYDATA对应的十六进制数为0x004A

wParam设置为包含数据的窗口的句柄。lParam指向一个COPYDATASTRUCT的结构:

typedef struct tagCOPYDATASTRUCT{

DWORD dwData;//用户定义数据

DWORD cbData;//数据大小

PVOID lpData;//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:

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

using System.Runtime.InteropServices;

 

namespace WindowsFormsApplication1

{

    public partial class Form1 : Form

    {

        const int WM_COPYDATA = 0x004A;

 

        public Form1()

        {

            InitializeComponent();

        }

 

        private void Form1_Load(object sender, EventArgs e)

        {

 

        }

 

        [DllImport("User32.dll",EntryPoint="SendMessage")]

         private static extern int SendMessage(

         int hWnd, // handle to destination window

         int Msg, // message

         int wParam, // first message parameter

         ref COPYDATASTRUCT lParam // second message parameter

        );

 

       [DllImport("User32.dll",EntryPoint="FindWindow")]

       private static extern int FindWindow(string lpClassName,string

       lpWindowName);

 

 

        private void button1_Click(object sender, EventArgs e)

        {

            int WINDOW_HANDLER = FindWindow(null,@"欲发送程序窗口的标题");

            if(WINDOW_HANDLER != 0)

            {

              byte[] sarr = System.Text.Encoding.Default.GetBytes(this.textBox1.Text);

              int len = sarr.Length;

              COPYDATASTRUCT cds;

              cds.dwData = (IntPtr) 100;

              cds.lpData = this.textBox1.Text;

              cds.cbData = len + 1;

              SendMessage(WINDOW_HANDLER, WM_COPYDATA, 0, ref cds);}

            }

        }

 

       public struct COPYDATASTRUCT

       {

          public IntPtr dwData;

          public int cbData;

          [MarshalAs(UnmanagedType.LPStr)]

           public string lpData;

       }

}

 

//---------------------------------------------------

//接受方

//---------------------------------------------------

using System;

using System.Drawing;

using System.Collections;

using System.ComponentModel;

using System.Windows.Forms;

using System.Data;

using System.Runtime.InteropServices;

namespace WindowsFormGetMsg

{

public class Form1 : System.Windows.Forms.Form

{

private System.Windows.Forms.TextBox textBox1;

private System.ComponentModel.Container components = null;

const int WM_COPYDATA = 0x004A;

public Form1()

{

InitializeComponent();

}

protected override void Dispose( bool disposing )

{

if( disposing )

{

if (components != null)

{

components.Dispose();

}

}

base.Dispose( disposing );

}

private void InitializeComponent()

{

this.textBox1 = new System.Windows.Forms.TextBox();

this.SuspendLayout();

//

// textBox1

//

this.textBox1.Location = new System.Drawing.Point(176, 32);

this.textBox1.Name = "textBox1";

this.textBox1.Size = new System.Drawing.Size(160, 21);

this.textBox1.TabIndex = 0;

this.textBox1.Text = "textBox1";

//

// Form1

//

this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);

this.ClientSize = new System.Drawing.Size(432, 266);

this.Controls.AddRange(new System.Windows.Forms.Control[] {

this.textBox1});

this.Name = "Form1";

this.Text = "接收方窗体";

this.ResumeLayout(false);

}

static void Main()

{

Application.Run(new Form1());

}

protected override void DefWndProc(ref System.Windows.Forms.Message m)

{

switch(m.Msg)

{

case WM_COPYDATA:

COPYDATASTRUCT mystr = new COPYDATASTRUCT();

Type mytype = mystr.GetType();

mystr =(COPYDATASTRUCT)m.GetLParam(mytype);

this.textBox1.Text =mystr.lpData;

break;

default:

base.DefWndProc(ref m);

break;

}

}

}

public struct COPYDATASTRUCT

{

public IntPtr dwData;

public int cbData;

[MarshalAs(UnmanagedType.LPStr)] public string lpData;

}

}

 

posted on 2013-10-22 10:23  荣锋亮  阅读(284)  评论(0编辑  收藏  举报

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