[转] [备忘]原生JS获取dom的左上坐标
<script>function getElementPos(elementId) { var ua = navigator.userAgent.toLowerCase(); var isOpera = (ua.indexOf('opera') != -1); var isIE = (ua.indexOf('msie') != -1 && !isOpera); // not opera spoof var el = document.getElementById(elementId); if(el.parentNode === null || el.style.display == 'none') { return false; } var parent = null; var pos = []; var box; if(el.getBoundingClientRect) //IE { box = el.getBoundingClientRect(); var scrollTop = Math.max(document.documentElement.scrollTop, document.body.scrollTop); var scrollLeft = Math.max(document.documentElement.scrollLeft, document.body.scrollLeft); return {x:box.left + scrollLeft, y:box.top + scrollTop}; } else if(document.getBoxObjectFor) // gecko { box = document.getBoxObjectFor(el); var borderLeft = (el.style.borderLeftWidth)?parseInt(el.style.borderLeftWidth):0; var borderTop = (el.style.borderTopWidth)?parseInt(el.style.borderTopWidth):0; pos = [box.x - borderLeft, box.y - borderTop]; } else // safari & opera { pos = [el.offsetLeft, el.offsetTop]; parent = el.offsetParent; if (parent != el) { while (parent) { pos[0] += parent.offsetLeft; pos[1] += parent.offsetTop; parent = parent.offsetParent; } } if (ua.indexOf('opera') != -1 || ( ua.indexOf('safari') != -1 && el.style.position == 'absolute' )) { pos[0] -= document.body.offsetLeft; pos[1] -= document.body.offsetTop; } } if (el.parentNode) { parent = el.parentNode; } else { parent = null; } while (parent && parent.tagName != 'BODY' && parent.tagName != 'HTML') { // account for any scrolled ancestors pos[0] -= parent.scrollLeft; pos[1] -= parent.scrollTop; if (parent.parentNode) { parent = parent.parentNode; } else { parent = null; } } return {x:pos[0], y:pos[1]};}</script>