AsyncTask的：哪里doInBackground的返回值（）去？ [英] AsyncTask: where does the return value of doInBackground() go?

问题描述

致电时的AsyncTask＆LT;整数，整数，布尔＆GT; ，其中是的返回值：

When calling AsyncTask<Integer,Integer,Boolean>, where is the return value of:

保护布尔doInBackground（整数... PARAMS）？

通常我们先从 AsyncTask的新AsyncTaskClassName（）执行（参数1，参数2 ......）; ，但它似乎并没有返回值。

Usually we start AsyncTask with new AsyncTaskClassName().execute(param1,param2......); but it doesn't appear to return a value.

在哪里可以的返回值doInBackground（）找到？

推荐答案

该值是那么<一个可用href=\"http://developer.android.com/intl/zh-TW/reference/android/os/AsyncTask.html#onPostExecute%28Result%29\">onPostExecute您可能要为了与结果的工作覆盖。

The value is then available in onPostExecute which you may want to override in order to work with the result.

下面是谷歌的文档例如code片断：

Here is example code snippet from Google's docs:

 private class DownloadFilesTask extends AsyncTask<URL, Integer, Long> {
      protected Long doInBackground(URL... urls) {
          int count = urls.length;
          long totalSize = 0;
          for (int i = 0; i < count; i++) {
              totalSize += Downloader.downloadFile(urls[i]);
              publishProgress((int) ((i / (float) count) * 100));
          }
          return totalSize;
      }

      protected void onProgressUpdate(Integer... progress) {
          setProgressPercent(progress[0]);
      }

      protected void onPostExecute(Long result) {
          showDialog("Downloaded " + result + " bytes");
      }
 }

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