如何在FragmentDialog显示时使应用程序全屏显示

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setStyle(DialogFragment.STYLE_NO_TITLE, android.R.style.Theme_Black_NoTitleBar_Fullscreen);
}

@Override
public void onStart() {
    super.onStart();
    Dialog dialog = getDialog();
    if (dialog != null) {
        dialog.getWindow().setLayout(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
    }
}