LoadMask jQuery插件用于当DOM元素加载或变化期间，对其进行遮挡阻止用户操作并告知有些后台任务还在进行。实现“正在加载中…”的效 果。整个插件只有1kb左右。-LoadMask jQuery plugin used to load or change when the DOM element during occlusion prevents users from operating it and inform some background task is still under