使用C#在应用程序间发送消息

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.cs   F:>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”。