Question

I have writing a mediaplayer app. When clicked on the play list button, ExpandList Activity launches and depending on which child is clicked, it should start my main activity and return the childposition. But it doenst do anything. There is no error or anything. It seems like its not even going into the onChildClick method and I am not sure why. I have looked at many examples and they all seem to have it the same why I have it. I was hoping someone could point out what I am doing wrong. Here is my code below. Thank you

import java.util.ArrayList;
import android.app.ExpandableListActivity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.ExpandableListView;
import android.widget.ExpandableListView.OnChildClickListener;
import android.widget.Toast;

public class ExpandListActivity extends ExpandableListActivity implements
OnChildClickListener {

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    ExpandableListView expandbleLis = getExpandableListView();
    expandbleLis.setDividerHeight(2);
    expandbleLis.setGroupIndicator(null);
    expandbleLis.setClickable(true);
    expandbleLis.setOnChildClickListener(this);

    setGroupData();
    setChildGroupData();

    NewAdapter mNewAdapter = new NewAdapter(groupItem, childItem);
    mNewAdapter
    .setInflater(
            (LayoutInflater)       getSystemService(Context.LAYOUT_INFLATER_SERVICE),
            this);
    expandbleLis.setAdapter(mNewAdapter);

}

public void setGroupData() {
    groupItem.add("TechNology");
    groupItem.add("Mobile");
    groupItem.add("Manufacturer");
    groupItem.add("Extras");
}

ArrayList<String> groupItem = new ArrayList<String>();
ArrayList<Object> childItem = new ArrayList<Object>();

public void setChildGroupData() {
    /**
     * Add Data For TecthNology
     */
    ArrayList<String> child = new ArrayList<String>();
    child.add("Java");
    child.add("Drupal");
    child.add(".Net Framework");
    child.add("PHP");
    childItem.add(child);

    /**
     * Add Data For Mobile
     */
    child = new ArrayList<String>();
    child.add("Android");
    child.add("Window Mobile");
    child.add("iPHone");
    child.add("Blackberry");
    childItem.add(child);
    /**
     * Add Data For Manufacture
     */
    child = new ArrayList<String>();
    child.add("HTC");
    child.add("Apple");
    child.add("Samsung");
    child.add("Nokia");
    childItem.add(child);
    /**
     * Add Data For Extras
     */
    child = new ArrayList<String>();
    child.add("Contact Us");
    child.add("About Us");
    child.add("Location");
    child.add("Root Cause");
    childItem.add(child);
}


@Override
public boolean onChildClick(ExpandableListView parent, View v,
        int groupPosition, int childPosition, long id) {

    Toast.makeText(ExpandListActivity.this, "Clicked On Child",
            Toast.LENGTH_SHORT).show();

    // Starting new intent
    Intent in = new Intent(getApplicationContext(),
            AndroidBuildingMusicPlayerActivity.class);

    // Sending childPosition to PlayerActivity
    in.putExtra("childPosition", childPosition);

    Log.println(0, getClass().getName(), "onChildClick inside");

    setResult(100, in);

    startActivity(in);

    // Closing PlayListView
    finish();


    return true;
}
}

Answer 1

If you are calling this activity using startActivityForResult(), then correct way to return to calling activity is as follows:

Intent returnIntent = new Intent();
returnIntent.putExtra("childPosition", childPosition);
setResult(RESULT_OK,returnIntent);        
finish();

So you need to remove these lines:

Intent in = new Intent(getApplicationContext(),
            AndroidBuildingMusicPlayerActivity.class);
startActivity(in);

Hope it helps.