Android: disable DialogFragment OK/Cancel buttons

问题:

How can I disable OK/Cancel button of a DialogFragment when it is created using an AlertDialog ? I tried calling myAlertDialogFragment.getDialog() but it's always returning null even once the fragment is displayed

public static class MyAlertDialogFragment extends DialogFragment {

    public static MyAlertDialogFragment newInstance(int title) {
        MyAlertDialogFragment frag = new MyAlertDialogFragment();
        Bundle args = new Bundle();
        args.putInt("title", title);
        frag.setArguments(args);
        return frag;
    }

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        int title = getArguments().getInt("title");

        return new AlertDialog.Builder(getActivity())
                .setIcon(R.drawable.alert_dialog_icon)
                .setTitle(title)
                .setPositiveButton(R.string.alert_dialog_ok,
                    new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int whichButton) {
                            ((FragmentAlertDialog)getActivity()).doPositiveClick();
                        }
                    }
                )
                .setNegativeButton(R.string.alert_dialog_cancel,
                    new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int whichButton) {
                            ((FragmentAlertDialog)getActivity()).doNegativeClick();
                        }
                    }
                )
                .create();
    }
}

I know I can to it by inflating a layout that contains both a cancel and an ok button, but I rather use the AlertDialog solution if possible

回答1:

Attach your AlertDialog to variable:

AlertDialog.Builder builder = new AlertDialog.Builder(this);
(initialization of your dialog)
AlertDialog alert = builder.create();
alert.show();

And then get button from your AlertDialogand set it disable/enable:

Button buttonNo = alert.getButton(AlertDialog.BUTTON_NEGATIVE);
buttonNo.setEnabled(false);

It give you opportunity to change button properties on runtime.

Then return your alert variable.

AlertDialog must be showed before acquiring its views.

回答2:

You need to override onStart() in DialogFragment and keep a reference to the button. You can then use the reference to re-enable the button later:

Button positiveButton;

@Override
public void onStart() {
    super.onStart();
    AlertDialog d = (AlertDialog) getDialog();
    if (d != null) {
        positiveButton = d.getButton(Dialog.BUTTON_POSITIVE);
        positiveButton.setEnabled(false);
    }

}