Android AsyncTask in external class

Question

I've been working on an app and I've managed to get the AsyncTask to work fine when it's an inner class, am refactoring the code so that the AsyncTask is a separate class on its own but am wondering how do I kill the ProgressDialog and start a new Activity once the task is completed successfully? I've tried starting a new Activity in the onPostExecute(..) method but I know that won't work

Answer 1

pass the Activity as a constructor parameter to your AsyncTask and keep it in a field. this is effectively what being an inner class was getting you (only the compiler would write the code for you).

Answer 2

All one needs to start a new Activity is the context object that you pass in the constructor of the AsyncTask:

    private Context ctx;
        private ProgressDialog pDialog;
        private String r="";



        public LoginTask(Context context){
            super();
            this.ctx=context;

        }

@Override
    protected void onPostExecute(String result) {


            Log.i("LOGGER", "Done...");
            pDialog.dismiss();
            Intent i=new Intent(ctx,SillyActivity.class);
            ctx.startActivity(i);


    }

If you pass the activity within the constructor in the AsyncTask and try to call startActivity(Intent intent) you will always get a null pointer exception..

Answer 3

Passing my UI thread activity as an argument in the constructor for the AsyncTask did not seem to work:

//In UI Thread I had
public class Test101 extends Activity {
    private Button btnLogin;
    private LoginTask mLoginTask;
    private Context context=this;
        private Test101 mTest101;

mLoginTask=new LoginTask(context,mTest101);
mLoginTask.execute(null);

//In the AsyncTask I had

Activity mParentActivity;

public LoginTask(Context context,Activity act){
this.ctx=context;
this.mParentActivity=act;
}

onPostExecute(..){
  mParentActivity.callSomeMethod();
}

I kept getting a NullPointerException, may be I'm missing something but that didn't work for me.