WinForm实现程序一段时间不运行自动关闭的方法

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Net;
using System.IO;
using System.Security.Cryptography.X509Certificates;
using System.Net.Security;
namespace DemoDataGridView
{
 public partial class Form3 : Form, IMessageFilter
 {
  private int m_WaitMinute = 0;
  System.Windows.Forms.Timer MyTimer;
  public Form3()
  {
   InitializeComponent();
   MyTimer = new Timer();
   MyTimer.Interval = 1000;
   MyTimer.Tick += new EventHandler(MyTimer_Tick);
   Application.Idle += new EventHandler(Application_Idle);
  }
  void MyTimer_Tick(object sender, EventArgs e)
  {
   if (m_WaitMinute < 60)
   {
    MyTimer.Enabled = true;
    MyTimer.Interval = 10000; //10秒
    m_WaitMinute += 1;
    // this.Opacity = 1.0 - Convert.ToDouble(m_WaitMinute / 60.0);
   }
   else
   {
    MyTimer.Enabled = false;
   }
  }
  void Application_Idle(object sender, EventArgs e)
  {
   if (m_WaitMinute == 0)
   {
    System.IO.File.WriteAllText("D:\\1.txt", DateTime.Now.ToString());
    MyTimer.Start();
   }
   else
   {
    if (m_WaitMinute >= 6)
    {
     System.IO.File.WriteAllText("D:\\2.txt", DateTime.Now.ToString());
     this.Close();
    }
   }
  }
  public bool PreFilterMessage(ref Message m)
  {
   if (m_WaitMinute != 0)
   {
    m_WaitMinute = 0;
    MyTimer.Enabled = false;
    return true;
   }
   return false;
  }
 }
}