android - 获取弹窗的度量

Question

我已经设置了弹出窗口，但我想将它置于按钮(View v)下方，需要点击才能打开它:

public void showPopup(Context c, View v){
    int[] location = new int[2];
    v.getLocationOnScreen(location);

    ViewGroup base = (ViewGroup) getView().findViewById(R.id.pup_pattern);  
    LayoutInflater inflater = (LayoutInflater) c.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    View pupLayout = inflater.inflate(R.layout.linearlayout_popup, base);

    final PopupWindow pup = new PopupWindow(pupLayout, android.view.ViewGroup.LayoutParams.WRAP_CONTENT, android.view.ViewGroup.LayoutParams.WRAP_CONTENT);

    int x = location[0] - (int) ((pupLayout.getWidth() - v.getWidth()) / 2 ); // --> pupLayout.getWidth() gives back -2?
    int y = location[1] + v.getHeight() + 10;

    pup.setFocusable(true);
    pup.showAtLocation(v, Gravity.NO_GRAVITY, x, y);
}

有人想采取措施吗？

Answer 1

你不会得到 View 的高度或宽度，它还没有在屏幕上绘制。

pupLayout.getWidth()//这会给你 0

你需要像这样得到宽度

int width = MeasureSpec.makeMeasureSpec(0, MeasureSpec. UNSPECIFIED);

这样使用

View pupLayout = inflater.inflate(R.layout.linearlayout_popup, base);
pupLayout.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 
            MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));

int x = location[0] - (int) ((pupLayout.getMeasuredWidth() - v.getWidth()) / 2 );