using System;

 using System.Collections.Generic;

 using System.ComponentModel;

 using System.Data;

 using System.Drawing;

 using System.Text;

 using System.Windows.Forms;

 using System.Runtime.InteropServices; 

 namespace WindowsApplication1

 {

     public partial class AutoDeleteMessageBox : Form

     {

         [DllImport("user32.dll", EntryPoint = "FindWindow", CharSet = CharSet.Auto)]

         private extern static IntPtr FindWindow(string lpClassName, string lpWindowName); 

         [DllImport("user32.dll", CharSet = CharSet.Auto)]

         public static extern int PostMessage(IntPtr hWnd, int msg, IntPtr wParam, IntPtr lParam); 

         public const int WM_CLOSE = 0x10; 

         public AutoDeleteMessageBox()

         {

             InitializeComponent();

         } 

         private void button1_Click(object sender, EventArgs e)

         {

             StartKiller();

             MessageBox.Show("3秒钟后自动关闭MessageBox窗口", "MessageBox");

         } 

         private void StartKiller()

         {

             Timer timer = new Timer();

             timer.Interval = ; //3秒启动

             timer.Tick += new EventHandler(Timer_Tick);

             timer.Start();

         } 

         private void Timer_Tick(object sender, EventArgs e)

         {

             KillMessageBox();

             //停止Timer

             ((Timer)sender).Stop();

         } 

         private void KillMessageBox()

         {

             //按照MessageBox的标题，找到MessageBox的窗口

             IntPtr ptr = FindWindow(null, "MessageBox");

             if (ptr != IntPtr.Zero)

             {

                 //找到则关闭MessageBox窗口

                 PostMessage(ptr, WM_CLOSE, IntPtr.Zero, IntPtr.Zero);

             }

         }

     }

 }