用js实现类似jquery里的animate动画效果

效果如下，鼠标移上，先宽度变化，再高度变化，最后透明度变化，鼠标移出，再依次变回去。

 

 

 

 

 

 

 

要点一：

startrun(obj,attr,target,fn)

box.onmouseover = function(){
startrun(box,"width",200,function(){
startrun(box,"height",200,function(){
startrun(box,"opacity","100")
});
});
}
如上面，函数也可以做为参数使用，就可以达到先执行某个动作，再执行某个动作的效果了。

 

要点二：

if(cur == target){
clearInterval(obj.timer);
if(fn){
fn();
}
}

当运动到达目标点，关闭定时器，然后就可以执行新的函数了。

 

最后，上代码

<!DOCTYPE html>
<html>
<head>
<meta charset="gb2312" />
<title>无标题文档</title>
<style>
<!--
body{margin:0; padding:0; font:12px/1.5 arial;}
#box{width:100px; height:100px; position:absolute; background:#06c; left:0;filter:alpha(opacity=30); opacity:0.3;}
-->
</style>
<script>
<!--
function getstyle(obj,name){
  if(obj.currentStyle){
      return obj.currentStyle[name];
    }else{
      return getComputedStyle(obj,false)[name];
    }
}

window.onload = function(){
  var box = document.getElementById("box");
    box.onmouseover = function(){
      startrun(box,"width",200,function(){
          startrun(box,"height",200,function(){
              startrun(box,"opacity","100")
            });
        });
    }
    box.onmouseout = function(){
      startrun(box,"height",100,function(){
          startrun(box,"width",100,function(){
              startrun(box,"opacity","30");
            });
        });
    }
}

function startrun(obj,attr,target,fn){
    clearInterval(obj.timer);
    obj.timer = setInterval(function(){
      var cur = 0;
        if(attr == "opacity"){
          cur = Math.round(parseFloat(getstyle(obj,attr))*100);
        }else{
          cur = parseInt(getstyle(obj,attr));
        }
      var speed = (target-cur)/8;
        speed = speed>0?Math.ceil(speed):Math.floor(speed);
        
        if(cur == target){
          clearInterval(obj.timer);
            if(fn){
              fn();
            }
        }else{
          if(attr == "opacity"){
                obj.style.filter = "alpha(opacity="+(cur+speed)+")";
              obj.style.opacity = (cur+speed)/100;
            }else{
            obj.style[attr] = cur + speed + "px";
            }
        }
        
    },30)
}
//-->
</script>
</head>

<body>
<div id="box">
</div>
</body>
</html>



 

 

 

 

 

posted @ 2012-03-14 10:54  jingangel  阅读(8596)  评论(0)  编辑  收藏  举报