线程交互
C# form 窗体

我使用了一个线程来执行上传, 我要把 上传的进度 显示在 form 窗体的label中

我直接在线程里面写 label.text = persent 赋值 报"线程间操作无效"

也用了事件 ,还是报错

这个应该怎么实现 谢谢

[解决办法]
说错了哈,是公共变量,而且Control.CheckForIllegalCrossThreadCalls = false;在某些控件跨线程调用的时候会出错,所以你最好使用其他的更安全的方法,.net2.0有个东西叫backgroundwork,可以帮你实现简单的异步操作和消息传递
[解决办法]

C# code

 
 using System; 
 using System.Threading; 
  
 namespace Cmpxx 
 { 
   public delegate void ExampleCallback(int lineCount); 
  
   public class ThreadArgState 
   { 
     private string boilerplate = ""; 
     private int value = 0; 
  
     private event ExampleCallback callback = null; 
  
     public ThreadArgState(string text, int number,ExampleCallback callbackDelegate) 
     { 
       boilerplate = text; 
       value = number; 
       callback = callbackDelegate; 
     } 
  
     public void ThreadProc() 
     { 
       Console.WriteLine(boilerplate, value); 
       Thread.Sleep(5000); 
       if (callback != null) 
       { 
         //触发事件 
         callback(20); 
       } 
     } 
   } 
  
   public class Example 
   { 
     public static void SCMain() 
     { 
       //主函数执行 
       ThreadArgState tws = new ThreadArgState("This report displays the number {0}.", 422, new ExampleCallback(ResultCallback)); 
  
       Thread t = new Thread(new ThreadStart(tws.ThreadProc)); 
       t.Start(); 
       Console.WriteLine("Main thread does some work, then waits."); 
       t.Join(); //等待线程处理完毕后才执行后面的程序,把他注释掉在看运行结果就明白了 
       Console.WriteLine("Independent task has completed; main thread ends."); 
     } 
  
     public static void ResultCallback(int lineCount) 
     { 
       Console.WriteLine("Independent task printed {0} lines.", lineCount); 
     } 
   } 
  
  
 }