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>