讓popupwindow顯示在某個控件的上方

private void showPopupWindow() {
    View mPopView = LayoutInflater.from(MyShopItemActivity.this).inflate(R.layout.shop_find_pop, null);

    PopupWindow mPopWindow = new PopupWindow(mPopView,ViewGroup.LayoutParams.WRAP_CONTENT,ViewGroup.LayoutParams.WRAP_CONTENT);

    mPopView.measure(View.MeasureSpec.UNSPECIFIED,View.MeasureSpec.UNSPECIFIED);

    int measuredWidth = mPopView.getMeasuredWidth();

    int measuredHeight = mPopView.getMeasuredHeight();

    int[] location = new int[2];

    mBtnFind.getLocationOnScreen(location);

    //有虛擬按鍵時添加
    mPopWindow.setSoftInputMode(PopupWindow.INPUT_METHOD_NEEDED);

    mPopWindow.setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE);

    mPopWindow.setBackgroundDrawable(new BitmapDrawable());

    mPopWindow.setFocusable(true);

    // 設置點擊其餘地方 就消失 (只設置這個，沒有效果) 必須設置背景
    mPopWindow.setOutsideTouchable(true);

    mPopWindow.setTouchable(true);

    //在控件上方顯示
    mPopWindow.showAtLocation(mBtnFind, Gravity.NO_GRAVITY, (location[0]+mBtnFind.getWidth()/2) - measuredWidth / 2, location[1] - measuredHeight);

    if (mPopWindow.isShowing()) {
        WindowManager.LayoutParams params = getWindow().getAttributes();
        params.alpha = 0.5f;
        getWindow().setAttributes(params);
    }

    mPopWindow.setOnDismissListener(new PopupWindow.OnDismissListener() {
        @Override
        public void onDismiss() {
            WindowManager.LayoutParams params = getWindow().getAttributes();
            params.alpha = 1f;
            getWindow().setAttributes(params);
        }
    });
}