api 25 PopupWindow会占据整个屏幕

解决方法:
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) { // Android 7.x中,PopupWindow高度为match_parent时,会出现兼容性问题,需要处理兼容性
    int[] mLocation = new int[2];
    stephenCommonTopTitleView.getTopTitleView().getLocationInWindow(mLocation);
    int offsetY = mLocation[1] + stephenCommonTopTitleView.getTopTitleView().getHeight();
    if (Build.VERSION.SDK_INT >= 25) { // Android 7.1中，PopupWindow高度为 match_parent 时，会占据整个屏幕
        //故而需要在 Android 7.1上再做特殊处理
        WindowManager wm = (WindowManager) activity.getSystemService(Context.WINDOW_SERVICE);
        int screenHeight = wm.getDefaultDisplay().getHeight();
        centWinShare.setHeight(screenHeight - offsetY); // 重新设置 PopupWindow 的高度
    }
    centWinShare.showAtLocation(stephenCommonTopTitleView.getTopTitleView(), Gravity.NO_GRAVITY, 0, offsetY);
} else {
    centWinShare.showAsDropDown(stephenCommonTopTitleView.getTopTitleView());
}

思路大概是这样
/*if (Build.VERSION.SDK_INT != 24) {
    //只有24这个版本有问题，好像是源码的问题
    showAsDropDown(view);
} else {
    //7.0 showAsDropDown没卵子用 得这么写
    int[] location = new int[2];
    view.getLocationOnScreen(location);
    int x = location[0];
    int y = location[1];
    showAtLocation(view, Gravity.NO_GRAVITY, 0, y + view.getHeight());
    //showAsDropDown(view, 0, marginTop);
}*/