在Android 7.0上PopupWindow.showAsDropDown位置偏移

解决方案：
用

if (Build.VERSION.SDK_INT < 24) {
                       popupWindow.showAsDropDown(view);
                   } else {
                       int[] location = new int[2];
                       view.getLocationOnScreen(location);
                       int x = location[0];
                       int y = location[1];
                       popupWindow.showAtLocation(view, Gravity.NO_GRAVITY, 0, y + view.getHeight());
                   }

替换：

popupWindow.showAsDropDown(view);

在部分机型上上述方法无效，可以尝试另一种方案：

if (Build.VERSION.SDK_INT > 24) {
                Rect rect = new Rect();
                mView.getGlobalVisibleRect(rect);
                int h = mView.getResources().getDisplayMetrics().heightPixels - rect.bottom;
                popWindow.setHeight(h);
            }
            categoryWindow.showAsDropDown(categoryView, 0, PhoneUtils.dp2px(getContext(), 0.5));