可实现页面的遮罩效果，纯js编写，图片可从网上随意下载一个静态或动态的图片，实现很简单，有相应的调用说明，希望大家希望，谢谢(Page mask effect can be achieved, written in pure JS, pictures can be downloaded from the Internet at random, a static or dynamic picture, the implementation is very simple, there is a co