What arguments are passed into AsyncTask?

Question

I don\'t understand what I am supposed to put in here and where these arguments end up? What exactly should I put, and where exactly will it go? Do I need to include all 3 o

Answer 1

Keep it simple!

An AsyncTask is background task which runs in the background thread. It takes an Input, performs Progress and gives Output.

ie AsyncTask.

In my opinion the main source of confusion comes when we try to memorize the parameters in the AsyncTask.
The key is Don't memorize.
If you can visualize what your task really needs to do then writing the AsyncTask with the correct signature would be a piece of cake.
Just figure out what your Input, Progress and Output are and you will be good to go.

For example:

Heart of the AsyncTask!

doInBackgound() method is the most important method in an AsyncTask because

• Only this method runs in the background thread and publish data to UI thread.
• Its signature changes with the AsyncTask parameters.

So lets see the relationship

doInBackground() and onPostExecute(),onProgressUpdate() are also related

Show me the code
So how will I write the code for DownloadTask?

DownloadTask extends AsyncTask{

      @Override
      public void onPreExecute()
      {}

      @Override
      public String doInbackGround(String... params)
      {
               // Download code
               int downloadPerc = // calculate that
               publish(downloadPerc);

               return "Download Success";
      }

      @Override
      public void onPostExecute(String result)
      {
          super.onPostExecute(result);
      }

      @Override
      public void onProgressUpdate(Integer... params)
      {
             // show in spinner, access UI elements
      }

}

How will you run this Task

new DownLoadTask().execute("Paradise.mp3");