WSGPFMMY 2014-10-18
获取元素准确位置的写法 知识点预备:getBoundingClientRect() clientTop,left:边框的距离 scrollTop,scrollLeft:到上边或者左边的滚动距离 pageYOffset:firefox 滚动条顶部到网页上边的距离 pageXOffset:firefox 滚动条顶部到网页左边的距离
var getCoords = function(el){ var box = el.getBoundingClientRect(), doc = el.ownerDocument, body = doc.body, html = doc.documentElement, clientTop = html.clientTop || body.clientTop || 0, clientLeft = html.clientLeft || body.clientLeft || 0, top = box.top + (self.pageYOffset || html.scrollTop || body.scrollTop ) - clientTop, left = box.left + (self.pageXOffset || html.scrollLeft || body.scrollLeft) - clientLeft return { 'top': top, 'left': left }; };