本文实例讲述了javascript实现拖动元素交换位置的代码。分享给大家供大家参考。具体如下：

实现目标：可拖动元素拖动到另外一个元素位置的时候，互相交换位置。

启发来源：最初形式是网上看到的一个拼图小游戏。

运行效果截图如下：

具体代码如下：

代码：

body,ul,li{margin:0;padding:0;} ul{list-style: none;} body{font:13px/1.5 Tahoma;} #box{position:relative;width:435px;height:580px;margin:10px auto;padding: 10px 5px 10px 10px;border: 1px solid #ccc;} #box li{float:left;width:80px;height:188px;overflow:hidden;background: #ccc;border: 1px solid #999;} #box li.hig{width:78px;height:186px;overflow:hidden;border:2px dashed blue;}

<ul id="box"></ul>

js代码：

var zIndex = 1;

window.onload = function() { var oBox = document.getElementById("box"); var aLi = oBox.getElementsByTagName("li"); var aPos = []; var aData = []; for (i = 0; i < 15; i++)aData.push(i+1); //插入结构 var oFragment = document.createDocumentFragment(); for (i = 0; i < aData.length; i++) { var oLi = document.createElement("li"); oFragment.appendChild(oLi) } oBox.appendChild(oFragment); //布局转换 for (i = 0; i < aLi.length; i++) { aLi[i].index = i; aLi[i].style.top = aLi[i].offsetTop + "px"; aLi[i].style.left = aLi[i].offsetLeft + "px"; aLi[i].style.margin = "0 5px 5px 0"; aPos.push({ "left": aLi[i].offsetLeft, "top": aLi[i].offsetTop }) } for (i = 0; i < aLi.length; i++) { aLi[i].style.position = "absolute"; drag(aLi[i]) } //拖拽函数 function drag(obj, handle) { var handle = handle || obj; handle.style.cursor = "move"; handle.onmousedown = function(event) { var event = event || window.event; var disX = event.clientX - this.offsetLeft; var disY = event.clientY - this.offsetTop; var oNear = null; obj.style.zIndex = zIndex++; document.onmousemove = function(event) { var event = event || window.event; var iL = event.clientX - disX; var iT = event.clientY - disY; var maxL = obj.parentNode.clientWidth - obj.offsetWidth; var maxT = obj.parentNode.clientHeight - obj.offsetHeight; iL < 0 && (iL = 0); iT < 0 && (iT = 0); iL > maxL && (iL = maxL); iT > maxT && (iT = maxT); obj.style.left = iL + "px"; obj.style.top = iT + "px"; for (i = 0; i < aLi.length; i++) aLi[i].className = ""; oNear = findNearest(obj); oNear && (oNear.className = "hig"); return false }; document.onmouseup = function() { document.onmousemove = null; document.onmouseup = null; if (oNear) { var tIndex = obj.index; obj.index = oNear.index; oNear.index = tIndex; startMove(obj, aPos[obj.index]); startMove(oNear, aPos[oNear.index], function() { }); oNear.className = ""; } else { startMove(obj, aPos[obj.index]) } handle.releaseCapture && handle.releaseCapture() }; this.setCapture && this.setCapture(); return false } } //找出相遇点中最近的元素 function findNearest(obj) { var filterLi = []; var aDistance = []; for (i = 0; i < aLi.length; i++) aLi[i] != obj && (isButt(obj, aLi[i]) && (aDistance.push(getDistance(obj, aLi[i])), filterLi.push(aLi[i]))); var minNum = Number.MAX_VALUE; var minLi = null; for (i = 0; i < aDistance.length; i++) aDistance[i] < minNum && (minNum = aDistance[i], minLi = filterLi[i]); return minLi } }; //求两点之间的距离 function getDistance(obj1, obj2) { var a = (obj1.offsetLeft + obj1.offsetWidth / 2) - (obj2.offsetLeft + obj2.offsetWidth / 2); var b = (obj1.offsetTop + obj1.offsetHeight / 2) - (obj2.offsetTop + obj2.offsetHeight / 2); return Math.sqrt(a * a + b * b) } //碰撞检测 function isButt(obj1, obj2) { var l1 = obj1.offsetLeft; var t1 = obj1.offsetTop; var r1 = obj1.offsetLeft + obj1.offsetWidth; var b1 = obj1.offsetTop + obj1.offsetHeight; var l2 = obj2.offsetLeft; var t2 = obj2.offsetTop; var r2 = obj2.offsetLeft + obj2.offsetWidth; var b2 = obj2.offsetTop + obj2.offsetHeight; return !(r1 < l2 || b1 < t2 || r2 < l1 || b2 < t1) } //获取最终样式 function getStyle(obj, attr) { return parseFloat(obj.currentStyle ? obj.currentStyle[attr] : getComputedStyle(obj, null)[attr]) } //运动框架 function startMove(obj, pos, onEnd) { clearInterval(obj.timer); obj.timer = setInterval(function() { doMove(obj, pos, onEnd) }, 30) } function doMove(obj, pos, onEnd) { var iCurL = getStyle(obj, "left"); var iCurT = getStyle(obj, "top"); var iSpeedL = (pos.left - iCurL) / 5; var iSpeedT = (pos.top - iCurT) / 5; iSpeedL = iSpeedL > 0 ? Math.ceil(iSpeedL) : Math.floor(iSpeedL); iSpeedT = iSpeedT > 0 ? Math.ceil(iSpeedT) : Math.floor(iSpeedT); if (pos.left == iCurL && pos.top == iCurT) { clearInterval(obj.timer); onEnd && onEnd() } else { obj.style.left = iCurL + iSpeedL + "px"; obj.style.top = iCurT + iSpeedT + "px"; } }

以上就是javascript实现拖动元素交换位置的全部代码，希望对大家的学习有所帮助。