Js(javascript)图片预载类。兼容IE,firefox(FF)

var FF=!IE && !Opera;
function LoadImage(arrSrc,callBack)
{
    this.Length=arrSrc.length;
    this.LoadedLen=0;    //已经被加载的图片个数
    var self=this;
    if(self.Length<1)
    {
        callBack(arrSrc);
        return;
    }

    //经测试,OPERA与别的浏览器加载方式不同,所以特别独立开来...
    if(Opera)
    {
        for(var i=0;i<self.Length;i++)
        {
            var tmpImg=new Image();
            tmpImg.src=arrSrc[i];
            tmpImg.onload=function()
            {
                self.LoadedLen++;
                if(self.LoadedLen==self.Length && callBack)    callBack(arrSrc);
            }
        }
        return;
    }

    this.Load=function()
    {
        self.LoadedLen++;
        document.getElementById("counter").innerHTML=self.LoadedLen;
        if(self.LoadedLen<self.Length)    self.DownImg();
        else if(callBack)    callBack(arrSrc);
    }

    this.DownImg=function()
    {
        var tmpImg=new Image();
        tmpImg.src=arrSrc[self.LoadedLen];
        if(IE)
        {
            if(tmpImg.readyState=="complete")    self.Load();
            else    tmpImg.onreadystatechange=function()
            {
                if(this.readyState=="complete")    self.Load();
            }
        }
        else    tmpImg.onload=self.Load;
    }
    this.DownImg();
}
//-->
</SCRIPT>
</HEAD>
<BODY>
<div id="counter"></div>
<SCRIPT LANGUAGE="JavaScript">

</SCRIPT>
</BODY>
</HTML>