其实行拖动的实现思路非常简单,选中一行,往上拖就与上面的行交换位置,往下拖就与下面的行交换位置。问题是如何得到交换行。我见过一个非常详细的教程,它会把表格里的每一行的高度与Y坐标计算出来,换言之,都是比较e.pageX是否在[rowTop,rowBottom]区间之内。
JS代码
<script type="text/javascript">
window.onload = function(){
//绑定事件
var addEvent = document.addEventListener ? function(el,type,callback){
el.addEventListener( type, callback, !1 );
} : function(el,type,callback){
el.attachEvent( "on" + type, callback );
}
//移除事件
var removeEvent = document.removeEventListener ? function(el,type,callback){
el.removeEventListener( type, callback );
} : function(el,type,callback){
el.detachEvent( "on" + type, callback);
}
//精确获取样式
var getStyle = document.defaultView ? function(el,style){
return document.defaultView.getComputedStyle(el, null).getPropertyValue(style)
} : function(el,style){
style = style.replace(/\-(\w)/g, function($, $1){
return $1.toUpperCase();
});
return el.currentStyle[style];
}
var dragManager = {
clientY:0,
draging:function(e){//mousemove时拖动行
var dragObj = dragManager.dragObj;
if(dragObj){
e = e || event;
if(window.getSelection){//w3c
window.getSelection().removeAllRanges();
}else if(document.selection){
document.selection.empty();//IE
}
var y = e.clientY;
var down = y > dragManager.clientY;//是否向下移动
var tr = document.elementFromPoint(e.clientX,e.clientY);
if(tr && tr.nodeName == "TD"){
tr = tr.parentNode
dragManager.clientY = y;
if( dragObj !== tr){
tr.parentNode.insertBefore(dragObj, (down ? tr.nextSibling : tr));
}
};
}
},
dragStart:function(e){
e = e || event;
var target = e.target || e.srcElement;
if(target.nodeName === "TD"){
target = target.parentNode;
dragManager.dragObj = target;
if(!target.getAttribute("data-background")){
var background = getStyle(target,"background-color");
target.setAttribute("data-background",background)
}
//显示为可移动的状态
target.style.backgroundColor = "#ccc";
target.style.cursor = "move";
dragManager.clientY = e.clientY;
addEvent(document,"mousemove",dragManager.draging);
addEvent(document,"mouseup",dragManager.dragEnd);
}
},
dragEnd:function(e){
var dragObj = dragManager.dragObj
if (dragObj) {
e = e || event;
var target = e.target || e.srcElement;
if(target.nodeName === "TD"){
target = target.parentNode;
dragObj.style.backgroundColor = dragObj.getAttribute("data-background");
dragObj.style.cursor = "default";
dragManager.dragObj = null;
removeEvent(document,"mousemove",dragManager.draging);
removeEvent(document,"mouseup",dragManager.dragEnd);
}
}
},
main:function(el){
addEvent(el,"mousedown",dragManager.dragStart);
}
}
var el = document.getElementById("table");
dragManager.main(el);
}
</script>
HTML代码
<table id="table" class="table">
<tbody>
<tr>
<td>1</td>
<td>One</td>
<td>dom.require</td>
</tr>
<tr id="2" >
<td class="2">2</td>
<td>Two</td>
<td>ControlJS </td>
</tr>
<tr id="3" >
<td class="3">3</td>
<td>Three</td>
<td>HeadJS</td>
</tr>
</tbody>
</table>