winform messagebox自动关闭

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 = 3000; //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);
            }
        }
    }
}