Android 7.0以上PopupWindow 位置异常

public static void showAsDropDown(final PopupWindow pw, final View anchor, final int xoff, final int yoff) {

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

        Rect visibleFrame = new Rect();

        anchor.getGlobalVisibleRect(visibleFrame);

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

        pw.setHeight(height);

        pw.showAsDropDown(anchor, xoff, yoff);

    } else {

        pw.showAsDropDown(anchor, xoff, yoff);

    }

}