android - 从 IntentService 显示 ProgressBar 或 Dialog 以获取下载进度

Question

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Answer 1

Is it possible to display ProgressBar or ProgressDialog from my DownloadService (which is extended IntentService), except the progress shown in the Notification bar?

Could you write a sample code or pseudo code how I can do that? Thank you

您可以使用 ResultReceiver 来达到您的目标。 ResultReceiver 实现了 Parcelable，因此您可以像这样将其传递到 IntentService 中:

Intent i = new Intent(this, DownloadService.class);
i.putExtra("receiver", new DownReceiver(new Handler()));
<context>.startService(i);

然后在您的 onHandlerIntent() 中，您需要做的就是获取您传递给 Intent 的接收器，并将当前进度发送给 ResultReceiver:

protected void onHandleIntent(Intent intent) {  

   // obtaining ResultReceiver from Intent that started this IntentService
   ResultReceiver receiver = intent.getParcelableExtra("receiver");

   ...

   // data that will be send into ResultReceiver
   Bundle data = new Bundle();
   data.putInt("progress", progress);

   // here you are sending progress into ResultReceiver located in your Activity
   receiver.send(Const.NEW_PROGRESS, data);
}

ResultReceiver 将处理数据并在 ProgressDialog 中进行更新。这是 ResultReceiver 的实现(将其作为 Activity 类的内部类):

private class DownReceiver extends ResultReceiver {

   public DownloadReceiver(Handler handler) {
      super(handler);
   }

   @Override
   public void onReceiveResult(int resultCode, Bundle resultData) {
      super.onReceiveResult(resultCode, resultData);
      if (resultCode == Const.NEW_PROGRESS) {
         int progress = resultData.getInt("progress");

         // pd variable represents your ProgressDialog
         pd.setProgress(progress);
         pd.setMessage(String.valueOf(progress) + "% downloaded sucessfully.");
      }
   }
}