Android AsyncTask problem

Question

Hi!

I have a string that I want to update using AsyncTask class here is my code:

public class MainActivity extends Activity{

private String str = "oldString";

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        getString();
        }
       private void getString(){
              new CustomTask().execute();
       }

     private class CustomTask extends AsyncTask<Void, Void, String>{

          @Override
          protected String doInBackground(Void... params) {
           // TODO Auto-generated method stub
           Log.i("Lesson3", "doInBackground method");
           str = "newString";
           return "someString";
          }

          protected void onPostExecute(String s){
           Log.i("Lesson3", "onPostExecute method");

          }

}

onPostExecute method is not called, thats the problem??

Thanks

Answer 1

public class MainActivity extends Activity {

    private String str = "oldString";

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

        getString();
    }

    private void getString() {
        new CustomTask().execute();
    }

    private void postExecuteCallback() {
        Log.i("Lesson3", "String after callback: " + str );
    }

    private class CustomTask extends AsyncTask<Void, Void, String> {

        @Override
        protected String doInBackground(Void... params) {
            // TODO Auto-generated method stub
            Log.i("Lesson3", "doInBackground method");
            str = "newString";
            return "someString";
        }

        protected void onPostExecute(String s) {
            Log.i("Lesson3", "onPostExecute method");
            postExecuteCallback();
        }
    }
}

Answer 2

Why have you decided it doesn't run? Following code works just fine (fixed syntax errors in yours):

package com.stackoverflow;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;

public class Test extends Activity {

private String str = "oldString";

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

    getString();
}

private void getString() {
    new CustomTask().execute();
}

private class CustomTask extends AsyncTask<Void, Void, String> {

    @Override
    protected String doInBackground(Void... params) {
        // TODO Auto-generated method stub
        Log.i("Lesson3", "doInBackground method");
        str = "newString";
        return "someString";
    }

    protected void onPostExecute(String s) {
        Log.i("Lesson3", "onPostExecute method");

    }

}

}