带有ShowAtLocation的OnCreate中的PopupWindow -如何获取父视图？

public class MainActivity extends AppCompatActivity {
    private PopupWindow popupWindow;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // 创建PopupWindow对象并设置内容视图
        popupWindow = new PopupWindow(this);
        View popupView = getLayoutInflater().inflate(R.layout.popup_layout, null);
        popupWindow.setContentView(popupView);

        // 获取父视图的引用
        View parentView = findViewById(R.id.parent_view);

        // 在OnCreate中使用ShowAtLocation方法设置PopupWindow的位置，并传入父视图的引用
        popupWindow.showAtLocation(parentView, Gravity.CENTER, 0, 0);
    }
}