align AlertDialog buttons to center

This worked for me :

    final AlertDialog.Builder builder = new AlertDialog.Builder(getActivity(), R.style.AppCompatAlertDialogStyle);
    builder.setCancelable(true);
    builder.setTitle(title);
    builder.setMessage(message);

    builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {

        }
    });


    final AlertDialog dialog = builder.create();
    dialog.show(); //show() should be called before dialog.getButton().


    final Button positiveButton = dialog.getButton(AlertDialog.BUTTON_POSITIVE);
    LinearLayout.LayoutParams positiveButtonLL = (LinearLayout.LayoutParams) positiveButton.getLayoutParams();
    positiveButtonLL.gravity = Gravity.CENTER;
    positiveButton.setLayoutParams(positiveButtonLL);

Use crtn's method, but instead of changing the LayoutParam's gravity, change its width to ViewGroup.LayoutParams.MATCH_PARENT;

If you want to have Positive And Negative Buttons at the same time (Large & Center), you can use something like this:

AlertDialog alertDialog = new AlertDialog.Builder(this).create();
alertDialog.setTitle("Title");
alertDialog.setMessage("Message");

alertDialog.setButton(AlertDialog.BUTTON_POSITIVE, "Yes",
        new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                dialog.dismiss();
            }
        });

alertDialog.setButton(AlertDialog.BUTTON_NEGATIVE, "No",
        new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                 dialog.dismiss();
            }
         });
alertDialog.show();

Button btnPositive = alertDialog.getButton(AlertDialog.BUTTON_POSITIVE);
Button btnNegative = alertDialog.getButton(AlertDialog.BUTTON_NEGATIVE);

LinearLayout.LayoutParams layoutParams = (LinearLayout.LayoutParams) btnPositive.getLayoutParams();
layoutParams.weight = 10;
btnPositive.setLayoutParams(layoutParams);
btnNegative.setLayoutParams(layoutParams);