Android Dialog在底部显示且宽度match_parent

@Override
protected void onCreate(Bundle savedInstanceState) {
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    super.onCreate(savedInstanceState);
    setContentView(getLayoutResId());
    getWindow().setLayout(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
    getWindow().setGravity(Gravity.BOTTOM | Gravity.CENTER_HORIZONTAL);
    getWindow().setBackgroundDrawable(null);
    getWindow().setWindowAnimations(R.style.PopupAnimation);
}