jQuery自定义图片尺寸上传预览特效代码

<link rel="stylesheet" href="https://apps.bdimg.com/libs/bootstrap/3.3.4/css/bootstrap.css">
<link rel="stylesheet" href="css/index.css">

<script src="js/jquery.min.js"></script>
<script src="js/bootstrap.min.js"></script>
<script src="js/index.js"></script>

<div class="box">
    <p>上传log</p>
    <p>
  <div class="upload imgLog">
      <span><i class="glyphicon glyphicon-open"></i>上传log0</span>       </div>
    </p>
    <p>上传头像</p>
    <p>
  <div class="upload imgLog2">
            <span><i class="glyphicon glyphicon-open"></i>上传头像</span>     </div>
    </p>  
    <p>上传海报</p>
    <p>
  <div class="upload imgLog3">
            <span><i class="glyphicon glyphicon-open"></i>上传海报</span>     </div>
    </p>          
</div>
<script>
    $(function(){
        var img1 = new ImgUpload('.imgLog',210,55,55);
        var img2 = new ImgUpload('.imgLog2',100,100,100);
        var img3 = new ImgUpload('.imgLog3',400,200,200);
        $(document).on('change',".imgLog input",function(e){
            //模拟后台返回url
            var url = window.URL.createObjectURL(e.target.files[0]);
            $(this).parent().css('background','url('+url+')0% 0% / cover')
            console.log(window.URL.createObjectURL(e.target.files[0]))
            img1.setSpan(this)
        })
        $(document).on('change',".imgLog2 input",function(e){
            //模拟后台返回url
            var url = window.URL.createObjectURL(e.target.files[0]);
            $(this).parent().css('background','url('+url+')0% 0% / cover')
            img2.setSpan(this)
        })  
        $(document).on('change',".imgLog3 input",function(e){
            //模拟后台返回url
            var url = window.URL.createObjectURL(e.target.files[0]);
            $(this).parent().css('background','url('+url+')0% 0% / cover')
            img3.setSpan(this)
        })                      
    })
</script>