关于上传的问题

版本：layuiAdmin 2.4.5

浏览器：IE11

上传多个文件时没有问题,但是如果删除其中一个再次上传,点击上传按钮是没用反映的?

代码如下:不知道哪里的问题

var demoListView = $('#open-bill-add-annexList');
        uploadListIns = upload.render({
            elem: '#testList'
            , url: layui.setter.APIURL.apiurl + 'base/uploadSource'
            , accept: 'file'
            , multiple: true
            , auto: false
            , headers: {'x_auth_token': token}
            , bindAction: '#testListAction'
            , choose: function (obj) {
                //demoListView.empty();
                //fileList.value = "";
                var files = this.files = obj.pushFile(); //将每次选择的文件追加到文件队列
                //读取本地文件
                obj.preview(function (index, file, result) {
                    var tr = $(['<tr id="upload-' + index + '">'
                        , '<td>' + file.name + '</td>'
                        , '<td>' + (file.size / 1014).toFixed(1) + 'kb</td>'
                        , '<td>等待上传</td>'
                        , '<td>'
                        , '<button class="layui-btn layui-btn-xs demo-reload layui-hide">重传</button>'
                        , '<button class="layui-btn layui-btn-xs layui-btn-danger demo-delete">删除</button>'
                        , '</td>'
                        , '</tr>'].join(''));

                    //单个重传
                    tr.find('.demo-reload').on('click', function () {
                        obj.upload(index, file);
                    });

                    //删除
                    tr.find('.demo-delete').on('click', function () {
                        delete files[index]; //删除对应的文件
                        tr.remove();
                        uploadListIns.config.elem.next()[0].value = ''; //清空 input file 值，以免删除后出现同名文件不可选
                    });
                    demoListView.append(tr);
                });
            }
            , done: function (res, index, upload) {
                if (res.code == 0) { //上传成功
                    var tr = demoListView.find('tr#upload-' + index)
                        , tds = tr.children();
                    tds.eq(2).html('<span >上传成功</span>');
                    tds.eq(3).find('.demo-delete').addClass('layui-hide');
                    //tds.eq(3).find('.demo-reload').removeClass('layui-hide'); //显示重传
                    //tds.eq(3).find('.demo-delete').removeClass('layui-hide'); //清空操作
                    fileList.value = fileList.value + "," + res.data;
                    return delete this.files[index]; //删除文件队列已经上传成功的文件
                }
                this.error(index, upload);
            }
            , error: function (index, upload) {
                var tr = demoListView.find('tr#upload-' + index)
                    , tds = tr.children();
                tds.eq(2).html('<span >上传失败</span>');
                tds.eq(3).find('.demo-reload').removeClass('layui-hide'); //显示重传
            }
        });