popupWindow 修复Android 24以上的定位锚点问题。

//重写showAsDropDown方法

@Override

public void showAsDropDown(View anchor) {

if(Build.VERSION.SDK_INT>=24) {

Rect visibleFrame =newRect();

anchor.getGlobalVisibleRect(visibleFrame);

intheight = anchor.getResources().getDisplayMetrics().heightPixels- visibleFrame.bottom;

setHeight(height);

}

super.showAsDropDown(anchor);

}