用HTML5的File API做上传图片预览功能

<title>河北草坪</title>
<input type="file" id="fileElem" multiple accept="image/*"  onchange="handleFiles(this)">
<div id="fileList" style="width:200px;height:200px;"></div>
<script>
    window.URL = window.URL || window.webkitURL;
    var fileElem = document.getElementById("fileElem"),
        fileList = document.getElementById("fileList");
    function handleFiles(obj) {
        var files = obj.files,
            img = new Image();
        if(window.URL){
            //File API
              alert(files[0].name + "," + files[0].size + " bytes");
              img.src = window.URL.createObjectURL(files[0]); //创建一个object URL，并不是你的本地路径
              img.width = 200;
              img.onload = function(e) {
                 window.URL.revokeObjectURL(this.src); //图片加载后，释放object URL
              }
              fileList.appendChild(img);
        }else if(window.FileReader){
            //opera不支持createObjectURL/revokeObjectURL方法。我们用FileReader对象来处理
            var reader = new FileReader();
            reader.readAsDataURL(files[0]);
            reader.onload = function(e){
                alert(files[0].name + "," +e.total + " bytes");
                img.src = this.result;
                img.width = 200;
                fileList.appendChild(img);
            }
        }else{
            //ie
            obj.select();
            obj.blur();
            var nfile = document.selection.createRange().text;
            document.selection.empty();
            img.src = nfile;
            img.width = 200;
            img.onload=function(){
              alert(nfile+","+img.fileSize + " bytes");
            }
            fileList.appendChild(img);
            //fileList.style.filter="progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=‘image‘,src=‘"+nfile+"‘)";
        }
    }
</script>