解决android7.0 popwindow设置showAsDropdown不显示在控件下方的问题

测量目标控件的位置，然后设置显示在固定位置即可

private void showPpw(PopupWindow popupWindow) {
        if (Build.VERSION.SDK_INT < 24) {
            popupWindow.showAsDropDown(view);
        } else {
            int[] location = new int[2];
            view.getLocationOnScreen(location);
            popupWindow.showAtLocation(mLine, Gravity.NO_GRAVITY, location[0], location[1] + 2);
        }
    }