2015-04-15 14:06:09
今天我来给大家介绍一种js特效，这种特效是当你用鼠标点击组件移动到其他地方后，这个组件就定在了那个地方，这种效果通常用来做视图化排版的。下面我来把代码贴出来给大家看看
代码语言：javascript复制 <div id="container">
<div class="column">
<div class="item">
<h3>Header</h3>
<p>column1 item1</p>
</div>
<div class="item">
<h3>Header</h3>
<p>column1 item2<br />Some text here, so that the height is different!</p>
</div>
<div class="item">
<h3>Header</h3>
<p>column1 item3</p>
</div>
<div class="item">
<h3>Header</h3>
<p>column1 item4</p>
</div>
</div>
<div class="column" style="width:300px;">
<div class="item">
<h3>Header</h3>
<p>column2 item1</p>
</div>
<div class="item">
<h3>Header</h3>
<p>column2 item2</p>
</div>
<div class="item">
<h3>Header</h3>
<p>column2 item3<br />Some text here, so that the height is different!</p>
</div>
<div class="item">
<h3>Header</h3>
<p>column2 item4<br />Some text here, so that the height is different!</p>
</div>
</div>
<div class="column">
<div class="item">
<h3>Header</h3>
<p>column3 item1</p>
</div>
<div class="item">
<h3>Header</h3>
<p>column3 item2</p>
</div>
<div class="item">
<h3>Header</h3>
<p>column3 item3</p>
</div>
<div class="item">
<h3>Header</h3>
<p>column3 item4</p>
</div>
</div>
</div>这段代码是html代码，主要是大体的div布局，我们在这里的组件用的是div，通过下面的js代码来实现组件的移动
代码语言：javascript复制<script type="text/javascript" src="Drag.js"></script>
<script type="text/javascript">
//------------------------Utility------------------------
function findPosX(obj) {//辅助函数 得到元素左边与浏览器左边的边距
var curleft = 0;
if (obj && obj.offsetParent) {
while (obj.offsetParent) {
curleft = obj.offsetLeft;
obj = obj.offsetParent;
}
} else if (obj && obj.x) curleft = obj.x;
return curleft;// document.body.scrollLeft - document.body.clientLeft;
}
function findPosY(obj) {//辅助函数 得到元素上边与浏览器上边的边距
var curtop = 0;
if (obj && obj.offsetParent) {
while (obj.offsetParent) {
curtop = obj.offsetTop;
obj = obj.offsetParent;
}
} else if (obj && obj.y) curtop = obj.y;
return curtop;// document.body.scrollTop - document.body.clientTop;
}
var dragGhost = document.createElement("div");
dragGhost.style.border = "dashed 1px #CCCCCC";
dragGhost.style.background = "white";
dragGhost.style.display = "none";
dragGhost.style.margin = "10px";
var container;
var columns = [];
//------------------------Start Here------------------------
window.onload = function(){
container = document.getElementById("container");
for(var i=0;i<container.childNodes.length;i ){
if(container.childNodes[i].className == "column"){//筛选出所有的列 ff下的childNodes不可靠 :
columns.push(container.childNodes[i]);
}
}
for(var i=0;i<columns.length;i ){
var column = columns[i];
for(var j=0;j<column.childNodes.length;j ){
var item = column.childNodes[j];
if(item.className == "item"){
item.column = column;//给每个拖拽对象要指明它属于哪一列 而且这个属性会随着拖动而更新的
new dragItem(item);
}
}
}
}
var isIE = document.all;
//------------------------Drag Item------------------------
function dragItem(item){
//item实际上是dragBody(拖动的时候移动的整体)
//在这里需要根据item找到handle(能够拖动的把手)
var handle;
for(var i=0;i<item.childNodes.length;i ){
if(item.childNodes[i].nodeName.toLowerCase() == "h3"){
handle = item.childNodes[i];
break;
}
}
if(!handle)return;
Drag.init(handle,item);
item.onDragStart = function(left,top,mouseX,mouseY){
//开始拖动的时候设置透明度
this.style.opacity = "0.5";
this.style.filter = "alpha(opacity=50)";
dragGhost.style.height = (isIE?this.offsetHeight:this.offsetHeight - 2) "px";
//this指的是item
this.style.width = this.offsetWidth "px";//因为初始的width为auto
this.style.left = (findPosX(this) - 5) "px";
this.style.top = (findPosY(this) - 5) "px";
this.style.position = "absolute";
//将ghost插入到当前位置
dragGhost.style.display = "block";
this.column.insertBefore(dragGhost,this);
//记录每一列的左边距 在拖动过程中判断拖动对象所在的列会用到
this.columnsX = [];
for(var i=0;i<columns.length;i ){
this.columnsX.push(findPosX(columns[i]));
}
}
item.onDrag = function(left,top,mouseX,mouseY){
//先要判断在哪一列移动
var columnIndex = 0;
for(var i=0;i<this.columnsX.length;i ){
if((left this.offsetWidth/2) > this.columnsX[i]){
columnIndex = i;
}
}
//如果columnIndex在循环中没有被赋值 则表示当前拖动对象在第一列的左边
//此时也把它放到第一列
var column = columns[columnIndex];
if(this.column != column){
//之前拖动对象不在这个列
//将ghost放置到这一列的最下方
column.appendChild(dragGhost);
this.column = column;
}
//然后在判断放在这一列的什么位置
var currentNode = null;
for(var i=0;i<this.column.childNodes.length;i ){
if(this.column.childNodes[i].className == "item"
&& this.column.childNodes[i] != this//不能跟拖动元素自己比较 否则不能在本列向下移动
&& top < findPosY(this.column.childNodes[i])){//从上到下找到第一个比拖动元素的上边距大的元素
currentNode = this.column.childNodes[i];
break;
}
}
if(currentNode)
this.column.insertBefore(dragGhost,currentNode);
else//拖到最下边 没有任何一个元素的上边距比拖动元素的top大 则添加到列的最后
this.column.appendChild(dragGhost);
}
item.onDragEnd = function(left,top,mouseX,mouseY){
this.style.opacity = "1";
this.style.filter = "alpha(opacity=100)";
this.column.insertBefore(this,dragGhost);
this.style.position = "static";
this.style.display = "block";
this.style.width = "auto";
dragGhost.style.display = "none";
}
}
</script>
<style type="text/css">
#container{width:800px;}
.column{width:200px;border:solid 1px #CCCCCC;background:#FCFCFC;padding:0px;float:left;margin:10px;}
.item{text-align:center;padding:0px;margin:10px;border:solid 1px #CCCCCC;background:white;width:auto;}
.item h3{margin:0px;height:20px;border-bottom:solid 1px #CCCCCC;background:#CCCCCC;color:white;cursor:move;}
</style>这样就可以实现组件的移动了，在上面这段代码中需要引入Drag.js文件，本站提供下载链接，点击下面的下载即可。
