最近在网上看到一些朋友到处找类似于google的个性主页和msn space的拖拽实现,在下正好也找到了一个例子.但是问题比较多.我将其改写并完善,建立了一个通用的函数.具体的函数实现如下:
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>BlackSoul的拖拽Demo</title>
<!--
____________________________________
|--------Author By BlackSoul---------|
|------------2006.03.30--------------|
|[email protected]------|
|------------QQ:9136194--------------|
|------http://blacksoul.cnblogs.cn---|
======================================
-->
<style type="text/css">
body
{
margin:0px;
}
#aim /*设置目标层样式*/
{
position:absolute;/*控制层的位置所必须的style*/
width:200px;
height:30px;
border:1px solid #666666;
background-color:#FFCCCC;
}
#sourceLayer, #cloneLayer
{
position:absolute;/*控制层的位置所必须的style*/
width:300px;
height:50px;
border:1px solid #666666;
background-color:#CCCCCC;
cursor:move;
}
.docked
{
display:none;
filter:alpha(opacity=100);
}
.actived
{
display:block;
filter:alpha(opacity=70);
}
</style>
</head>
<body >
<div id="aim">放置范围</div>
<div id="sourceLayer" unselectable="off"><img src="
<div id="cloneLayer" class="docked" unselectable="off"></div> <script type="text/javascript" language="javascript"> <!-- /* ==================================== |--------Author By BlackSoul---------| |------------2006.03.30--------------| |[email protected]------| |------------QQ:9136194--------------| |------http://blacksoul.cnblogs.cn---| ==================================== */ //设置层对象 var aim; var sourceLayer; var cloneLayer; //定义各个层初始位置 var aimX; var aimY; var orgnX; var orgnY; //拖拽过程中的变量 var draging = false; //是否处于拖拽中 var offsetX = 0; //X方向左右偏移量 var offsetY = 0; //Y方向上下偏移量 var back; //返回动画对象 var thisX ; //当前clone层的X位置 var thisY ; //当前clone层的Y位置 var time ; var stepX ; //位移速度 var stepY ; //位移速度 //初始化拖拽信息 /* initAimX 目标x坐标 initAimY 目标y坐标 initOrgnX 拖拽源x坐标 initOrgnY 拖拽源y坐标 */ //获得层对象 function getLayer(inAim,inSource,inClone) { aim = document.getElementById(inAim); sourceLayer = document.getElementById(inSource); cloneLayer = document.getElementById(inClone); } function initDrag(initAimX,initAimY,initOrgnX,initOrgnY) { aimX = initAimX; aimY = initAimY; orgnX = initOrgnX; orgnY = initOrgnY; //设置各个开始层的位置 aim.style.pixelLeft = aimX; aim.style.pixelTop = aimY; sourceLayer.style.pixelLeft = orgnX; sourceLayer.style.pixelTop = orgnY; cloneLayer.style.pixelLeft = orgnX; cloneLayer.style.pixelTop = orgnY; } //准备拖拽 function BeforeDrag() { if (event.button != 1) { return; } cloneLayer.innerHTML = sourceLayer.innerHTML; //复制拖拽源内容 offsetX = document.body.scrollLeft + event.clientX - sourceLayer.style.pixelLeft; offsetY = document.body.scrollTop + event.clientY - sourceLayer.style.pixelTop; cloneLayer.className = "actived"; draging = true; } //拖拽中 function OnDrag() { if(!draging) { return; } //更新位置 event.returnValue = false; cloneLayer.style.pixelLeft = document.body.scrollLeft + event.clientX - offsetX; cloneLayer.style.pixelTop = document.body.scrollTop + event.clientY - offsetY; } //结束拖拽 function EndDrag() { if (event.button != 1) { return; } draging = false; if (event.clientX >= aim.style.pixelLeft && event.clientX <= (aim.style.pixelLeft + aim.offsetWidth) && event.clientY >= aim.style.pixelTop && event.clientY <= (aim.style.pixelTop + aim.offsetHeight)) { //拖拽层位于目标中，自动定位到目标位置 sourceLayer.style.pixelLeft = aim.style.pixelLeft; sourceLayer.style.pixelTop = aim.style.pixelTop; cloneLayer.className = "docked"; /* ** 这里完成之后可以用xml保存当前位置. ** 下次用户进入的时候 ** 就初始化源拖拽层为xml当中的数据了 */ } else { //拖拽位于目标层外，将拖拽源位置复原 thisX = cloneLayer.style.pixelLeft; thisY = cloneLayer.style.pixelTop; offSetX = Math.abs(thisX - orgnX); offSetY = Math.abs(thisY - orgnY); time = 500;//设置动画时间 stepX = Math.floor((offSetX/time)*20); stepY = Math.floor((offSetY/time)*20); if(stepX == 0) stepX = 2; if(stepY == 0) stepY = 2; //开始返回动画 moveStart(); } } function moveStart() { back = setInterval("MoveLayer();",15); } //设置返回的动画效果 function MoveLayer() { //位于目标左上 if(cloneLayer.style.pixelLeft <= orgnX && cloneLayer.style.pixelTop <= orgnY) { cloneLayer.style.pixelLeft += stepX; cloneLayer.style.pixelTop += stepY; //如果位移超过目标则设置速度为pix.并向反方向回移.此处实现了弹簧效果.下同 if(cloneLayer.style.pixelLeft > orgnX) { stepX = 1; } if(cloneLayer.style.pixelTop > orgnY) { stepY = 1; } //在X或Y轴上坐标相同则不发生位移 if(cloneLayer.style.pixelLeft == orgnX) { stepX = 0; } if(cloneLayer.style.pixelTop == orgnY) { stepY = 0; } if(cloneLayer.style.pixelLeft == orgnX && cloneLayer.style.pixelTop == orgnY) { EndMove(); } } //位于目标左下 else if(cloneLayer.style.pixelLeft <= orgnX && cloneLayer.style.pixelTop >= orgnY) { cloneLayer.style.pixelLeft += stepX; cloneLayer.style.pixelTop -= stepY; if(cloneLayer.style.pixelLeft > orgnX) { stepX = 1; } if(cloneLayer.style.pixelTop < orgnY) { stepY = 1; } if(cloneLayer.style.pixelLeft == orgnX) { stepX = 0; } if(cloneLayer.style.pixelTop == orgnY) { stepY = 0; } if(cloneLayer.style.pixelLeft == orgnX && cloneLayer.style.pixelTop == orgnY) { EndMove(); } } //位于目标右上 else if(cloneLayer.style.pixelLeft >= orgnX && cloneLayer.style.pixelTop <= orgnY) { cloneLayer.style.pixelLeft -= stepX; cloneLayer.style.pixelTop += stepY; if(cloneLayer.style.pixelLeft < orgnX) { stepX = 1; } if(cloneLayer.style.pixelTop > orgnY) { stepY = 1; } if(cloneLayer.style.pixelLeft == orgnX) { stepX = 0; } if(cloneLayer.style.pixelTop == orgnY) { stepY = 0; } if(cloneLayer.style.pixelLeft == orgnX && cloneLayer.style.pixelTop == orgnY) { EndMove(); } } //位于目标右上 else if(cloneLayer.style.pixelLeft >= orgnX && cloneLayer.style.pixelTop >= orgnY) { cloneLayer.style.pixelLeft -= stepX; cloneLayer.style.pixelTop -= stepY; if(cloneLayer.style.pixelLeft < orgnX) { stepX = 1; } if(cloneLayer.style.pixelTop < orgnY) { stepY = 1; } if(cloneLayer.style.pixelLeft == orgnX) { stepX = 0; } if(cloneLayer.style.pixelTop == orgnY) { stepY = 0; } if(cloneLayer.style.pixelLeft == orgnX && cloneLayer.style.pixelTop == orgnY) { EndMove(); } } //到达目标 else { EndMove(); } } //停止返回动画 function EndMove() { sourceLayer.style.pixelLeft = orgnX; sourceLayer.style.pixelTop = orgnY; cloneLayer.style.pixelLeft = orgnX; cloneLayer.style.pixelTop = orgnY; cloneLayer.className = "docked"; clearInterval(back); } //主拖拽函数 function startDraging(inAim,inSource,inClone,initAimX,initAimY,initOrgnX,initOrgnY) { getLayer(inAim,inSource,inClone) initDrag(initAimX,initAimY,initOrgnX,initOrgnY); sourceLayer.onmousedown = BeforeDrag; document.onmousemove = OnDrag; //这里如果用cloneLayer,在拖拽中会选中cloneLayer里面内容,进而出现一些bug... cloneLayer.onmouseup = EndDrag; } //调用 startDraging("aim","sourceLayer","cloneLayer",300,200,20,20); //--> </script> </body> </html> 需要注意的是: 仅IE里面测试通过.代码里面添加了注释.可以在拖拽源到达目标之后添加写xml的操作.进而记录用户自定义页面排版的数据.对于返回动画的算法还不是很满意.希望各位多多提些建议.以便完善.小弟当前致力于开发一套基于asp.net2.0的ajax控件.希望多多交流. ps:偶的博客园的第一篇文章.望多多支持.
一.html里面对于div的定义需要有三个. 三个层都必须定义style的position为absolute,以便控制位置
1.目标层(aim),主要作用是定义拖拽生效的位置.
2.拖拽源(sourceLayer).注意设置属性unselectable = "off"(这里比较奇怪,设置成on范围会在拖拽过程中选中层内容)
3.用于复制的层(cloneLayer).
二.函数的调用
startDraging参数解释:
initAim 目标层名称 initSource 拖拽源名称 initClone 用于复制的层的名称
initAimX 目标层x轴坐标 initAimY 目标层y轴坐标 initOrgnX 拖拽源x坐标 initOrgnY 拖拽源Y轴坐标