c# - 向后台 worker 发送参数？

Question

假设我想向后台工作人员发送一个 int 参数，如何实现？

private void worker_DoWork(object sender, DoWorkEventArgs e) {

}

我知道这是什么时候 worker.RunWorkerAsync();，我不明白如何在 worker_DoWork 中定义它应该采用一个 int 参数。

Answer 1

你可以这样开始:

int value = 123;
bgw1.RunWorkerAsync(argument: value);  // the int will be boxed

然后

private void worker_DoWork(object sender, DoWorkEventArgs e) 
{
   int value = (int) e.Argument;   // the 'argument' parameter resurfaces here

   ...

   // and to transport a result back to the main thread
   double result = 0.1 * value;
   e.Result = result;
}


// the Completed handler should follow this pattern 
// for Error and (optionally) Cancellation handling
private void worker_Completed(object sender, RunWorkerCompletedEventArgs e) 
{
  // check error, check cancel, then use result
  if (e.Error != null)
  {
     // handle the error
  }
  else if (e.Cancelled)
  {
     // handle cancellation
  }
  else
  {          
      double result = (double) e.Result;
      // use it on the UI thread
  }
  // general cleanup code, runs when there was an error or not.
}