Question

Hello I want to use async task and this is my sceleton code:

public class MyActivity extends Activity {
    private ProgressDialog pd = null;
    private Object data = null;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        // Show the ProgressDialog on this thread
        this.pd = ProgressDialog.show(this, "Working..", "Downloading Data...", true, false);

        // Start a new thread that will download all the data
        new DownloadTask().execute("Any parameters my download task needs here");
    }

    private class DownloadTask extends AsyncTask<String, Void, Object> {
         protected Object doInBackground(String... args) {
             Log.i("MyApp", "Background thread starting");

             // This is where you would do all the work of downloading your data

             return "replace this with your data object";
         }

         protected void onPostExecute(Object result) {
             // Pass the result data back to the main activity
             MyActivity.this.data = result;

             if (MyActivity.this.pd != null) {
                 MyActivity.this.pd.dismiss();
             }
         }
    }  

My question is what should be the third argument in the AsyncTask if I my do InBackground function return both a string array and a bitmap? Any help?

Answer 1

I don’t think there’s support for returning two things from an AsyncTask. You could use a simple inner class to hold your return data:

public class MyActivity ... {
   class DownloadTaskResult {
       String stringResult;
       Bitmap bitmapResult;
   }

   class DownloadTask ... extends AsyncTask<String, Void, DownloadTaskResult> {
       protected DownloadTaskResult doInBackground(String... args){
           //your work; return a DownloadTaskResult with the String and Bitmap you want
       }
   }
}