javascript 中ondragstart ondrag实现拖动界面元素效果 .

<html> 
<head> 
<title></title> 
<script language="javascript" type="text/javascript">
function showpos() 

   document.all.x.value = event.clientX; 
   document.all.y.value = event.clientY; 

function Point() 

   this.x, this.y; 
   this.eventpos = function() 
   { 
      this.x = event.clientX; 
      this.y = event.clientY; 
   } 
   this.setpos = function(pt) 
   { 
      this.x = pt.x; 
      this.y = pt.y; 
   } 
 

var ptPre = new Point(); 
var ptCur = new Point(); 
 
function move(ptTo, ptFrom) 

   ox = ptTo.x - ptFrom.x; 
   oy = ptTo.y - ptFrom.y; 
   event.srcElement.style.posLeft += ox; 
   event.srcElement.style.posTop += oy; 

</script>  
 
<style type="text/css"> 
.dr 

position : relative ; 
cursor : hand ; 
event:expression( 
ondragstart=function() 

ptCur.eventpos(); 
ptPre.eventpos(); 
}, 
ondrag=function(){ 
    ptCur.eventpos(); 
     move(ptCur,ptPre); 
    ptPre.setpos(ptCur); 



</style>
</head> 
<body  onmousemove="showpos()" > 
<form> 
<div class="dr">X:<input  name="x" id="x" type="text"></input></div> 
<div class="dr">Y:<input name="y" id="y" type="text"></input></div> 
</form> 
<img class="dr" src="free_register.gif" mce_src="free_register.gif" /> 
<br/> 
<div class="dr">Select me,and drag</div> 
</body> 
</html> 
原文地址:https://www.cnblogs.com/lidabo/p/2455315.html