<input type="file" name="image" class="upfile" size="3" value="" id="demo1">
 <img src="/static/images/upload_200_150.jpg" class="layui-upload-img 
preview-picture" id="demo3" width="80" height="80" 

onerror="javascript:this.src='/static/images/upload_200_150.jpg';">












<js程式碼>
    $(document).ready(function () {
        $("#demo1").change(function () {
            var objUrl = pic_ture(this.files[0]);
        });
    })
    function pic_ture(pic) {
        var r = new FileReader();
        r.readAsDataURL(pic);
        r.onload = function (e) {
            $("#demo3").attr("src", this.result).show();
        };
    }
 

主要是js   難看實用