JS 图片自适应大小

js

//缩放多张图片
function ZoomAllPicture(pictureid,setformatwidth,setformatheight)
{
    //var allItem = document.getElementsByTagName("Img");
    var formatwidth = parseInt(setformatwidth);  //设定格式化宽度
    var formatheight = parseInt(setformatheight); //设定格式化高度
    var outwidth;          //输出宽度
    var outheight;         //输出高度
    var width;             //原图片宽度
    var height;            //原图片高度
    
    $("img[id="+pictureid+"]").each(function(i,n){
        width = parseInt($(this).width());
        height = parseInt($(this).height());
        
        var rateWidth = formatwidth / width;
        var rateHeight = formatheight / height;
        
        if(rateWidth > rateHeight){
            outheight = setformatheight;
            outwidth = width * rateHeight;
        }
        else{
            outheight = height * rateWidth;
            outwidth = formatwidth
        }
        $(this).attr("width",outwidth);
        $(this).attr("height",outheight);
    });
}