本文实例讲述了C#实现在应用程序间发送消息的方法。分享给大家供大家参考，具体如下：

首先建立两个C#应用程序项目。

第一个项目包含一个Windows Form(Form1),在Form1上有一个Button和一个TextBox。

第二个项目包含一个Windows Form(Form1),在Form1上有两个Button，分别用来测试第一个应用程序中Button的Click事件和修改第一个应用程序中TextBox的值。

第一个应用程序中Form的代码如下:

using System;using System.Drawing;using System.Collections;using System.ComponentModel;using System.Windows.Forms;public class Form1 : System.Windows.Forms.Form { private System.Windows.Forms.Button button1; private System.Windows.Forms.TextBox textBox1; private System.ComponentModel.Container components = null; [STAThread] static void Main() { Application.Run(new Form1()); } public Form1() { InitializeComponent(); } protected override void Dispose( bool disposing ) { if( disposing ) { if(components != null) { components.Dispose(); } } base.Dispose( disposing ); } #region Windows 窗体设计器生成的代码 private void InitializeComponent() { this.button1 = new System.Windows.Forms.Button(); this.textBox1 = new System.Windows.Forms.TextBox(); this.SuspendLayout(); // // button1 // this.button1.Location = new System.Drawing.Point(32, 24); this.button1.Name = "button1"; this.button1.TabIndex = 0; this.button1.Text = "button1"; this.button1.Click += new System.EventHandler(this.button1_Click); // // textBox1 // this.textBox1.Location = new System.Drawing.Point(32, 64); this.textBox1.Name = "textBox1"; this.textBox1.TabIndex = 1; this.textBox1.Text = "textBox1"; // // Form1 // this.AutoScaleBaseSize = new System.Drawing.Size(6, 14); this.ClientSize = new System.Drawing.Size(292, 266); this.Controls.Add(this.textBox1); this.Controls.Add(this.button1); this.Name = "Form1"; this.Text = "Form1"; this.ResumeLayout(false); } #endregion private void button1_Click(object sender, System.EventArgs e) { MessageBox.Show("This is button1 click!"); }}

第二个应用程序中Form的代码如下:

using System;using System.Text;using System.Drawing;using System.Collections;using System.ComponentModel;using System.Windows.Forms;using System.Runtime.InteropServices;public class TestForm1 : System.Windows.Forms.Form { private System.Windows.Forms.Button button1; private System.Windows.Forms.Button button2; private System.ComponentModel.Container components = null; [STAThread] static void Main() { Application.Run(new TestForm1()); } public TestForm1() { InitializeComponent(); } protected override void Dispose( bool disposing ) { if( disposing ) { if(components != null) { components.Dispose(); } } base.Dispose( disposing ); } #region Windows 窗体设计器生成的代码 private void InitializeComponent() { this.button1 = new System.Windows.Forms.Button(); this.button2 = new System.Windows.Forms.Button(); this.SuspendLayout(); // // button1 // this.button1.Location = new System.Drawing.Point(32, 24); this.button1.Name = "button1"; this.button1.TabIndex = 0; this.button1.Text = "button1"; this.button1.Click += new System.EventHandler(this.button1_Click); // // button2 // this.button2.Location = new System.Drawing.Point(32, 64); this.button2.Name = "button2"; this.button2.TabIndex = 0; this.button2.Text = "button2"; this.button2.Click += new System.EventHandler(this.button2_Click); // // TestForm1 // this.AutoScaleBaseSize = new System.Drawing.Size(6, 14); this.ClientSize = new System.Drawing.Size(292, 266); this.Controls.Add(this.button1); this.Controls.Add(this.button2); this.Name = "TestForm1"; this.Text = "TestForm1"; this.ResumeLayout(false); } #endregion private void button1_Click(object sender, System.EventArgs e) { IntPtr hwnd_win ; IntPtr hwnd_button ; hwnd_win = FindWindow("WindowsForms10.Window.8.app3","Form1"); hwnd_button = FindWindowEx(hwnd_win ,new IntPtr(0) ,"WindowsForms10.BUTTON.app3","button1"); const int BM_CLICK = 0x00F5; Message msg = Message.Create(hwnd_button ,BM_CLICK ,new IntPtr(0),new IntPtr(0)); PostMessage(msg.HWnd ,msg.Msg ,msg.WParam ,msg.LParam); } private void button2_Click(object sender, System.EventArgs e) { const int WM_CHAR = 0x0102; IntPtr hwnd_win ; IntPtr hwnd_textbox ; hwnd_win = FindWindow("WindowsForms10.Window.8.app3","Form1"); hwnd_textbox = FindWindowEx(hwnd_win ,new IntPtr(0) ,"WindowsForms10.EDIT.app3","textBox1"); string strtext = "测试aaa"; UnicodeEncoding encode = new UnicodeEncoding(); char[] chars = encode.GetChars(encode.GetBytes(strtext)); Message msg ; foreach (char c in chars ) { msg = Message.Create(hwnd_textbox ,WM_CHAR ,new IntPtr(c),new IntPtr(0)); PostMessage(msg.HWnd ,msg.Msg ,msg.WParam ,msg.LParam); } } [DllImport("user32.dll")] public static extern IntPtr FindWindow(string lpClassName, string lpWindowName); [DllImport("user32.dll")] public static extern IntPtr FindWindowEx(IntPtr hwndParent,IntPtr hwndChildAfter,string lpszClass,string lpszWindow); [DllImport("user32.dll",CharSet=CharSet.Unicode)] public static extern IntPtr PostMessage(IntPtr hwnd,int wMsg,IntPtr wParam,IntPtr lParam);}

以上代码可以在VS.NET中编译运行，也可以使用csc.exe编译,如使用一下命令行：

F:>csc.exe Form1.csF:>csc.exe TestForm1.cs

编译后生成两个.exe文件。

首先运行第一个程序，显示Form1窗体，然后运行第二个程序，显示TestForm1窗体。

在TestForm1窗体上点击button1按钮（向Form1窗体上的button1发送消息）此时显示对话框提示“This is button1 click!”。

在TestForm1窗体上点击button2按钮（向Form1窗体上的textBox1发送消息）此时在Form1上的textBox1上显示“测试aaa”。

更多关于C#相关内容感兴趣的读者可查看本站专题：《WinForm控件用法总结》、《C#窗体操作技巧汇总》、《C#数据结构与算法教程》、《C#常见控件用法教程》、《C#面向对象程序设计入门教程》及《C#程序设计之线程使用技巧总结》

希望本文所述对大家C#程序设计有所帮助。