private void button6_Click(object sender, EventArgs e) 
{ 
   Thread demoThread =new Thread(new ThreadStart(threadMethod)); 
   demoThread.IsBackground = true; 
   demoThread.Start();//启动线程 
} 
 
 void threadMethod() 
 {  
   Action<String> AsyncUIDelegate=delegate(string n){label1.Text=n;};/<span style="font-family: Arial, Helvetica, sans-serif;">/定义一个委托</span> 
   label1.Invoke(AsyncUIDelegate,new object[]{"修改后的label1文本"}); 
 } 

SynchronizationContext _syncContext = null; 
 
private void button6_Click(object sender, EventArgs e) 
{ 
  Thread demoThread =new Thread(new ThreadStart(threadMethod)); 
  demoThread.IsBackground = true; 
  demoThread.Start();//启动线程 
} 
 
//窗体构造函数   
public Form1() 
{ 
  InitializeComponent(); 
   //获取UI线程同步上下文 
  _syncContext = SynchronizationContext.Current; 
} 
 
private void threadMethod() 
{ 
   _syncContext.Post(SetLabelText, "修改后的文本");//子线程中通过UI线程上下文更新UI 
} 
  
private void SetLabelText(object text) 
{ 
  this.lable1.Text = text.ToString(); 
}