How does BackgroundWorker use async thread to munipulate UI

How does BackgroundWorker use async thread to munipulate UI

• meo1985

  BackgroundWorker.DoWork event if for the method that's supposed to run asyncronoulsly i.e. not on UI thread, and after it finished it'll invoke RunWorkerCompleted
  
  
  private void button1_Click(object sender, EventArgs e) 
  { 
  BackgroundWorker worker = new BackgroundWorker(); 
  worker.DoWork+=new DoWorkEventHandler(worker_DoWork); 
  worker.RunWorkerCompleted+=new RunWorkerCompletedEventHandler(worker_RunWorkerCompleted); 
  } 
  
  // this is not UI
  void worker_DoWork(object sender, DoWorkEventArgs e) 
  { 
      // this line should no call UI object
      //  this.Text = "help me"; 
     DoLongWork();
  }
  
  void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) 
  { 
     // this can run on UI
      this.Text = "help me"; 
  }
  
  
  
• How does BackgroundWorker use async thread to munipulate UI