多线程中如何操作textBox?
public   partial   class   Main   :   Form 
 { 
             public   Main() 
             { 
                         InitializeComponent(); 
             }   
             private   void   button1_Click(object   sender,   EventArgs   e) 
             { 
                         Thread   tdTmp   =   new   Thread(new   ThreadStart(new   Hebf(ref   textBox1).test)); 
                         tdTmp.Start(); 
                         tdTmp.Join(); 
             } 
 } 
 class   Hebf 
 { 
             TextBox   textBox_Main; 
             public   Hebf(ref   TextBox   textBox_MainTmp) 
             { 
                         this.textBox_Main   =   textBox_MainTmp; 
             } 
             public   void   test() 
             { 
                         textBox_Main.Text   +=    "asad ";//这样出错 
             } 
 } 
 不同的class里怎么操作?
------解决方案--------------------change 
 Thread tdTmp = new Thread(new ThreadStart(new Hebf(ref textBox1).test)); 
 to 
 Hebf hebf = new Hebf(ref textBox1); 
 Thread tdTmp = new Thread(new ThreadStart(hebf.test));
------解决方案--------------------//这样测试看看   
 private void button1_Click(object sender, EventArgs e) 
 { 
     Thread tdTmp = new Thread(new ThreadStart(new Hebf(textBox1).test)); 
     tdTmp.Start(); 
     //tdTmp.Join(); 
 }   
 class Hebf  
 { 
     TextBox textBox_Main; 
     public Hebf(TextBox textBox_MainTmp) 
     { 
         textBox_Main = textBox_MainTmp; 
     }   
     public void test() 
     { 
         textBox_Main.Invoke(new EventHandler(DoInvoke)); 
     } 
     private void DoInvoke(object sender, EventArgs e) 
     { 
         textBox_Main.Text +=  "asad "; 
     } 
 }