align AlertDialog buttons to center

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

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);

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);