js实现完美拖拽效果可拖动层与回放拖动规迹并显示拖动距离参数_布局与层

<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>完美拖拽</title> <style type="text/css"> html,body{overflow:hidden;} body,div,h2,p{margin:0;padding:0;} body{color:#fff;background:#000;font:12px/2 Arial;} p{padding:0 10px;margin-top:10px;} span{color:#ff0;padding-left:5px;} #box{position:absolute;width:300px;height:150px;background:#333;border:2px solid #ccc;top:50%;left:50%;margin:-75px 0 0 -150px;} #box h2{height:25px;cursor:move;background:#222;border-bottom:2px solid #ccc;text-align:right;padding:0 10px;} #box h2 a{color:#fff;font:12px/25px Arial;text-decoration:none;outline:none;} </style> <script type="text/javascript"> window.onload=function () { var oBox=document.getElementById("box"); var oH2 = oBox.getElementsByTagName("h2")[0]; var oA = oBox.getElementsByTagName("a")[0]; var aSpan = oBox.getElementsByTagName("span"); var disX = disY = 0; var bDrag = false; var aPos = [{x:oBox.offsetLeft, y:oBox.offsetTop}] //鼠标按下, 激活拖拽 oH2.onmousedown = function (event) { var event = event || window.event; bDrag = true; disX = event.clientX - oBox.offsetLeft; disY = event.clientY - oBox.offsetTop; aPos.push({x:oBox.offsetLeft, y:oBox.offsetTop}) this.setCapture && this.setCapture(); return false }; //拖拽开始 document.onmousemove = function (event) { if (!bDrag) return; var event = event || window.event; var iL = event.clientX - disX; var iT = event.clientY - disY; var maxL = document.documentElement.clientWidth - oBox.offsetWidth; var maxT = document.documentElement.clientHeight - oBox.offsetHeight; iL = iL < 0 ? 0 : iL; iL = iL > maxL ? maxL : iL; iT = iT < 0 ? 0 : iT; iT = iT > maxT ? maxT : iT; oBox.style.marginTop = oBox.style.marginLeft = 0; oBox.style.left = iL + "px"; oBox.style.top = iT + "px"; aPos.push({x:iL, y:iT}) status(); return false }; //鼠标释放, 结束拖拽 document.onmouseup = window.onblur = oH2.onlosecapture = function () { bDrag = false; oH2.releaseCapture && oH2.releaseCapture(); status() }; //回放拖动轨迹 oA.onclick = function () { if (aPos.length == 1) return; var timer = setInterval(function () { var oPos = aPos.pop(); oPos ? (oBox.style.left = oPos.x + "px", oBox.style.top = oPos.y + "px", status()) : clearInterval(timer) }, 30); this.focus = false;//去除链接虚线 return false }; //阻止冒泡 oA.onmousedown = function (event) { (event || window.event).cancelBubble = true }; //监听状态函数 function status () { aSpan[0].innerHTML = bDrag; aSpan[1].innerHTML = oBox.offsetTop; aSpan[2].innerHTML = oBox.offsetLeft } //初始调用 status() }; </script> <div id="box"> <h2><a href="javascript:;">点击回放拖动轨迹</a></h2> <p><strong>Drag:</strong><span></span></p> <p><strong>offsetTop:</strong><span></span></p> <p><strong>offsetLeft:</strong><span></span></p> </div>
[Ctrl+A 全选 注:如需引入外部Js需刷新才能执行]