如何等待兩個BackgrandWorker的RunWorkerCompleted事件完成？

Question

這是代碼：

private void button1_Click(object sender, EventArgs e) 
    { 
     ParaClass pcs = new ParaClass(); 
     pcs.strPath = textBox1.Text; 
     pcs.sendedGrid = ugSrc; 
     this.backgroundWorker1.RunWorkerAsync(pcs); 

     ParaClass pcsB = new ParaClass(); 
     pcsB.strPath = textBox2.Text; 
     pcsB.sendedGrid = ultraGrid2; 

     this.backgroundWorker2.RunWorkerAsync(pcsB); 

     doSomething(); 
    } 

，並在這兩個backgrandworker1 & backgrandworker2「完滿成功事件，我這樣寫代碼：

private void backgroundWorker1_RunWorkerCompleted(object sender,RunWorkerCompletedEventArgs e) 
    { 
      doSomethingelsebk1(); 
    } 

    private void backgroundWorker2_RunWorkerCompleted(object sender,RunWorkerCompletedEventArgs e) 
    { 
      doSomethingelsebk2(); 
    } 

現在的問題是：在Button1的的點擊事件的函數DoSomething的（）必須等待雙方完成事件的完成。 如果我改變DoSomething的（）來

private void backgroundWorker2_RunWorkerCompleted(object sender,RunWorkerCompletedEventArgs e) 
    { 
      doSomethingelsebk2(); 
      doSomething(); 
    } 

然後，因爲有兩個線程，我不知道哪個線程將首先完成，所以如何解決

Answer 1

創建2個標誌代表完整的狀態2的BackgroundWorker。

打開RunWorkerCompleted事件中的各個標誌，然後調用doSomething()方法。

在doSomething方法中，檢查兩個標誌是否都打開，然後繼續執行，否則返回。

Answer 2

創建2個AutoResetEvents，在每個Background工作完成時設置它們，並在主方法中用WaitHandle等待它們全部。

WaitHandle[] handles = new WaitHandle[] { new AutoResetEvent(false), new AutoResetEvent(false)}; 

private void button1_Click(object sender, EventArgs e) 
{ 
    ParaClass pcs = new ParaClass(); 
    pcs.strPath = textBox1.Text; 
    pcs.sendedGrid = ugSrc; 
    this.backgroundWorker1.RunWorkerAsync(pcs); 

    ParaClass pcsB = new ParaClass(); 
    pcsB.strPath = textBox2.Text; 
    pcsB.sendedGrid = ultraGrid2; 

    this.backgroundWorker2.RunWorkerAsync(pcsB); 

    WaitHandle.WaitAll(this.handles); 
    doSomething(); 
} 


private void backgroundWorker1_RunWorkerCompleted(object sender,RunWorkerCompletedEventArgs e) 
{ 
     doSomethingelsebk1(); 
     ((AutoResetEvent)this.handles[0]).Set(); 
} 

private void backgroundWorker2_RunWorkerCompleted(object sender,RunWorkerCompletedEventArgs e) 
{ 
     doSomethingelsebk2(); 
     ((AutoResetEvent)this.handles[1]).Set(); 
}