JS引用：
<script type="text/javascript" src="~/bootstrap/js/fileinput.min.js"></script>
<link href="~/bootstrap/css/fileinput.min.css" rel="stylesheet" />
<script src="~/Scripts/lib/jquery.json.js"></script>



HTML: <input id="fileUpload" type="file"  >


JS: 
    //自动上传文件-JS
    function initFileInput(ctrlName, uploadUrl) {
        var control = $('#' + ctrlName);

        control.fileinput({
            language: 'zh', //设置语言
            uploadUrl: uploadUrl, //上传的地址  (该方法需返回JSON字符串)
            allowedFileExtensions: ['xlsx', 'xls', 'txt'],//接收的文件后缀
            showUpload: false, //是否显示上传按钮
            showCaption: true,//是否显示标题
            browseClass: "btn btn-primary", //按钮样式
            //previewFileIcon: "<i class='glyphicon glyphicon-king'></i>",
            uploadExtraData: { ID: "123" }
        }).on('filebatchselected', function (event, data, id, index) {
            $(this).fileinput("upload");
        }).on("fileuploaded", function (event, data) {
            if (data.response) {
               
           //通过 data.response.Json对象属性 获得返回数据
           errors = data.response.ErrorList;
            }
        })
    }


//上传JS初始化
    $(function () {
        initFileInput("fileUpload", "Controllers/Action");
    });




//获取上传文件弹窗关闭动作
$("#fileUpload").change(function () { alert("上传文件弹窗已关闭") })



参考资料：http://www.oschina.net/code/snippet_269752_55899

C#后台保存处理：

            //上传文件
            string root = "~/Upload/Files/StorageOutFile/";
            string path = Server.MapPath(root);
            string datePath = string.Empty;
            datePath += DateTime.Now.Year.ToString();
            datePath += DateTime.Now.Month.ToString("D2");
            datePath += DateTime.Now.Day.ToString("D2") + "/";
            root += datePath;
            if (path != null)
            {
                path += datePath;
                if (!Directory.Exists(Path.GetDirectoryName(path)))
                {
                    Directory.CreateDirectory(Path.GetDirectoryName(path));
                }
            }
            string fileName = root + CurUser.StaffName + DateTime.Now.ToString("yyyyMMddhhmmssffff") + Path.GetExtension(Request.Files[0].FileName);
            string fileUrl = Server.MapPath(fileName);
            //保存文件
            Request.Files[0].SaveAs(fileUrl);


            //读取EXCEL
            DataSet ds = new DataSet();
            Workbook workbook = new Workbook(fileUrl);
            Worksheet sheet = workbook.Worksheets[0];
            Cells cells = sheet.Cells;
            DataTable tab = new DataTable();
            for (int i = 0; i <= cells.MaxColumn; i++)
            {
                tab.Columns.Add(cells[0, i].StringValue.Trim(), typeof(System.String));
            }
            for (int i = 1; i <= cells.MaxDataRow; i++)
            {
                DataRow dr = tab.NewRow();
                for (int j = 0; j <= cells.MaxDataColumn; j++)
                {
                    string data = cells[i, j].StringValue.Trim();
                    dr[j] = data;
                }
                tab.Rows.Add(dr);
            }
            ds.Tables.Add(tab);
            DataTable dt = ds.Tables[0];