title: asynctask cancel onpostexecute
body: <p>i have a try and catch in "doInBackground", i dont wan the code be run the onPostExecute if the apps execute catch method in "doInBackground". code as below: </p>
  
  <pre><code>public class DownloadFileAsync extends AsyncTask&lt;String, Integer, Void&gt; {
          @Override
          protected void onPreExecute(){
               super.onPreExecute();
       }
  
      @Override
      protected Void doInBackground(String... aurl) {
          try{
             //some code, jump to onPostexecute after complete
          }
          catch{
              //some code, don't do onPostExecute after complete
          }
          return null;
  
          }
  
      @Override
      protected void onProgressUpdate(Integer... progress) {          
      //some code
      }
  
      @Override
      protected void onPostExecute(Void unused) {
      //some code
      }
  }
  </code></pre>