how can i receive value from AlertDialog(class) box in MainActivity(class) without passing control to AlertDialog class(Android Development)

Question

Description: I have created AlertDialogBox Class, when i need the dialog box to pop-up i use alertDialog.show(), dialog box pop-up takes input as YES/NO(button as positive and negative) and stay on the same activity, but how can i get the value ie yes or no , and pass value enter by the user in the mainActivity from the dialog box. Tried:- I tried using bundle, using put/get and key value, but its return null value. tried using global variable but still null value.

Thanks for the help

Answer 1

You could do this by using an interface and the getActivity() and getParentFragment() methods of the DialogFragment class.

Note: I'm assuming (since you didn't post any code) that your already using a DialogFragment to show the AlertDialog.

First create the dialog and a special interface which can be used to pass the value to the owning Activity or Fragment :

public class MyAlertDialog extends DialogFragment implements DialogInterface.OnClickListener {

    public interface MyAlertDialogResultInterface {
        abstract void onButtonClicked(int button);
    }

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
        builder.setMessage("Test message");
        builder.setPositiveButton("Ok", this);
        builder.setNegativeButton("No", this);
        return builder.create();
    }

    @Override
    public void onClick(DialogInterface dialogInterface, int button) {
        //Check if this DialogFragment is owned by a parent fragment
        if(getParentFragment() instanceof MyAlertDialogResultInterface){
            ((MyAlertDialogResultInterface) getParentFragment()).onButtonClicked(button);

        //Else check if this DialogFragment is owned by a parent activity
        } else if(getActivity() instanceof MyAlertDialogResultInterface){
            ((MyAlertDialogResultInterface) getActivity()).onButtonClicked(button);
        }
    }
}

Than add the special interface to your Activity and use the FragmentManager to show the dialog:

public class Test extends Activity implements MyAlertDialog.MyAlertDialogResultInterface {


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //Set up layout
    }

    private void showAlertDialog(){
        new MyAlertDialog().show(getFragmentManager(), "dialog-tag");
    }

    @Override
    public void onButtonClicked(int button) {
        //Do what ever you want to do
    }
}

Answer 2

Main Activity:

private void registerClickCallBack(){

    ListView list = (ListView)findViewById(R.id.starListView);
    list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        StarClassValue clickedPosition = myStar.get(position);

        Str = clickedPosition.getStarName();
        String intr = clickedPosition.getIconNum() +"";
            //Toast.makeText(MainActivity.this,Str + intr,Toast.LENGTH_LONG).show();
            sendMessage(Str,intr);


        }
    });

    list.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
        @Override
        public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
            StarClassValue click = myStar.get(position);
            String str = click.getStarName();


         dialog.show(getFragmentManager(),"Favourite");

            return false;
        }
    });
}

AlertDialog Class

public class AlertDialogFragment extends DialogFragment {

@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
    Context context = getActivity();
    final AlertDialog.Builder builder = new AlertDialog.Builder(context);

    builder.setTitle("Add to Favorite").setMessage("Do you want to add this artist to your favourite list").setPositiveButton("OK", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {

        }
    }).setNegativeButton("Cancel", null);
    AlertDialog dialog = builder.create();


    return dialog;
}

}

So, how should i pass "yes" value received from AlertDialogFragment class into main activity without passing intent or control.