winform 线程挂起无成效

winform 线程挂起无效果
代码如下：
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Threading;

namespace pro7
{
  public partial class Form1 : Form
  {
  public Form1()
  {
  InitializeComponent();
  }
  public Thread t;
  private void Form1_Load(object sender, EventArgs e)
  {
  CheckForIllegalCrossThreadCalls = false;
  t = new Thread(gettime);
  t.Start();
  }
  public void gettime()
  {
  while (true)
  {
  textBox1.Text = DateTime.Now.ToString();
  Thread.Sleep(1000);
  }
  }

  private void button1_Click(object sender, EventArgs e)
  {
  if (t.ThreadState == ThreadState.Running)
  {
  t.Suspend();
  }
  }

  private void button2_Click(object sender, EventArgs e)
  {
  if (t.ThreadState == ThreadState.Suspended || t.ThreadState == ThreadState.SuspendRequested)
  {
  t.Resume();
  }
  }
  }
}

[解决办法]

C# code

using System;using System.Threading;using System.Windows.Forms;namespace WindowsFormsApplication1{    public partial class Form1 : Form    {        public Form1()        {            InitializeComponent();        }        private ManualResetEvent _ManualResetEvent = new ManualResetEvent(true);        private Boolean _bAbort = false;        private void Form1_Load(object sender, EventArgs e)        {            CheckForIllegalCrossThreadCalls = false;            Thread t = new Thread(gettime);            t.Start();        }        public void gettime()        {            while (!_bAbort)            {                textBox1.Text = DateTime.Now.ToString();                Thread.Sleep(1000);                _ManualResetEvent.WaitOne();            }        }        private void button1_Click(object sender, EventArgs e)        {            _ManualResetEvent.Reset();        }        private void button2_Click(object sender, EventArgs e)        {            _ManualResetEvent.Set();        }        private void Form1_FormClosing(object sender, FormClosingEventArgs e)        {            _bAbort = true;        }    }}