【JavaScript】画面元素(图片)可拖动的技术实现收藏

这个关键是用好3个事件,一个是onmousedown一个是onmousemove一个是onmouseup
onmousedown记录当前鼠标所触发的对象,在onmousemove所触发的方法中进行移动,onmouseup放下拖动的对象。

代码:

<script language="javascript">
  var checkMoving;
  function divMove(){
    checkMoving = false;
    document.onmousedown=startMove;
    document.onmousemove=moveObj;
    document.onmouseup=new Function("checkMoving = false");
  }

  function startMove(){
    if(event.srcElement.className!="imgObj") return;
    checkMoving=true;
    Xdiff=event.clientX-event.srcElement.style.pixelLeft;
    Ydiff=event.clientY-event.srcElement.style.pixelTop;
  }

  function moveObj(){
    if(!checkMoving) return true;
    event.srcElement.style.pixelLeft=event.clientX-Xdiff;
    event.srcElement.style.pixelTop=event.clientY-Ydiff;
    return false;
  }
</script>

<body style="margin: auto;" onLoad="divMove();">
<div style="left:0;top:0;position:relative;overflow:hidden;width:100%;height:100%" id="div1">
<img src="default.gif" style="position:relative;left:0px;top:0px;width:100px;height:100px;cursor:hand;" class=imgObj>
</div>
</body>

你可能感兴趣的:(JavaScript,html)