在ASP.NET MVC站点上载文件（不上传）

Question

我在asp.net mvc网站上设置了一个上传文件功能。代码不会抛出任何错误，但我选择上传的文件不会存储在指定位置。以下是我的代码。

控制器

public ActionResult uploadCourseList(HttpPostedFileBase file)
    {

            var filename = Path.GetFileName(file.FileName);
            var path = Path.Combine(Server.MapPath("~/App_Data"), filename);
            file.SaveAs(path);

            KuPlanEntities db = new KuPlanEntities();

            var user = "000000001";

            var userIdvar = (from userId in db.AspNetUsers
                             where userId.Id == user
                             select userId.Id).ToString();

            var stuList = (from users in db.AspNetUsers
                           where users.advisor == user
                           select new listStudentViewModel { Id = users.Id, fname = users.fname, lname = users.lname });

        return View("~/Views/ManageStudentCourses/Index.cshtml", stuList);
    }

查看

 <div id="uploadCourseList">
        @using (Html.BeginForm("uploadCourseList", "ManageStudentCourses", FormMethod.Post, new { enctype = "multipart/form-data" }))
        {
            @Html.AntiForgeryToken()
            <table class="courseListTable">
                <tr>
                    <th colspan="4">
                        Upload Course List
                    </th>
                </tr>
                <tr>
                    <td>
                        Select a file:
                    </td>
                    <td>
                        <input type="file" name="file" id="file" />
                    </td>
                    <td>
                        <input type="submit">
                    </td>
                </tr>
            </table>
        }
    </div>