Android AlertDialog with DialogFragment: don't close the dialog even if OK is clicked

Question

I have an AlertDialog with a custom layout (just an EditText) and I want to validate the data when the OK button is clicked. If the validation fails I don't want to close the dialog.

I'm using dialog's default buttons (positive and negative). If I use "setPositiveButton("", new DialogInterface.OnClickListener() ..." the dialog is always closed. I've seen several posts and they said that the onClick Listener should be override, but I can't get it working. This is the code I found:

Button theButton = dialog.getButton(DialogInterface.BUTTON_POSITIVE);
theButton.setOnClickListener(new CustomListener(dialog));

Since it says it should be done AFTER showing the dialog I placed this code inside my activity, not inside my DialogFragment, but if I use mDialogFragment.getDialog() it always returns null.

This is a part of my Dialog Fragment:

@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
    // Use the Builder class for convenient dialog construction
    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());

    builder.setTitle(R.string.new);

    LayoutInflater inflater = getActivity().getLayoutInflater();
    dialogView = inflater.inflate(R.layout.edit_license, null);

    builder.setView(dialogView)

    // Add action buttons
    .setPositiveButton(R.string.ok, new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int id) {

        }
    })
    .setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int id) {
            MyDialogFragment.this.getDialog().cancel();
        }
    }); 

    return builder.create();

}

And in my Activity I do the following:

DialogFragment dialog = new MyDialogFragment(true, null);
dialog.show(getSupportFragmentManager(), "EditLicenseDialogFragment");

AlertDialog alertDialog = (AlertDialog)dialog.getDialog();
alertDialog.getButton(DialogInterface.BUTTON_POSITIVE);
btnPositive.setOnClickListener(new CustomListener(alertDialog));

... 

class CustomListener implements View.OnClickListener {
    private final Dialog dialog;
    public CustomListener(Dialog dialog) {
        this.dialog = dialog;
    }
    @Override
    public void onClick(View v) {
        ...
    }
}

Like I said, (AlertDialog)dialog.getDialog(); always returns null. Why is that? How can I avoid closing the dialog if the validation is not ok?

Thanks!

Answer 1

This solution works for me. Dialog is already visible in onResume so this is a good place to get access to buttons and replace listeners.

public class XYZFragment extends DialogFragment {
   ...

    @Override
    public void onResume() {
        super.onResume();

        AlertDialog dialog = (AlertDialog)getDialog();

        Button positiveButton = dialog.getButton(DialogInterface.BUTTON_POSITIVE);
        positiveButton.setOnClickListener(new View.OnClickListener() {                  
            @Override
            public void onClick(View onClick) {
            ...
            }
        });
    }
}

Answer 2

here is some text from reference of DialogFragment:

A fragment that displays a dialog window, floating on top of its activity's window. This fragment contains a Dialog object, which it displays as appropriate based on the fragment's state. Control of the dialog (deciding when to show, hide, dismiss it) should be done through the API here, not with direct calls on the dialog.

Instead of calling getDialog().dismiss() you should do dismiss()