popup menu window

MainActivityCallMe.java

   private PopupWindow popTrainMenu() {
        LayoutInflater inflater = LayoutInflater.from(this);
        View view = inflater.inflate(R.layout.train_popwindow_menu, null);
        Display display = getWindowManager().getDefaultDisplay();
        Point size = new Point();
        display.getSize(size);
        int width = size.x;
        int height = size.y;
        Log.v("zxy", "width=" + width + ",height=" + height);
        PopupWindow popWindow = new PopupWindow(view, 2 * width / 5, ViewGroup.LayoutParams.WRAP_CONTENT, true);
        popWindow.setBackgroundDrawable(new BitmapDrawable());//设置PopupWindow的背景为一个空的Drawable对象，如果不设置这个，那么PopupWindow弹出后就无法退出了
        popWindow.setOutsideTouchable(true);
        WindowManager.LayoutParams params = getWindow().getAttributes();
        params.alpha = 0.8f;
        getWindow().setAttributes(params);
        popWindow.setOnDismissListener(() -> {
            WindowManager.LayoutParams params1 = getWindow().getAttributes();
            params1.alpha = 1.0f;
            getWindow().setAttributes(params1);
        });
        //popWindow.showAtLocation(titleBarLayout, Gravity.TOP | Gravity.RIGHT, 20, titleBarLayout.getHeight() + Utils.getStatusBarHeight(this) - 10);
        //popWindow.showAsDropDown(rightTextView);

        return popWindow;
    }