如何在ASP.Net MVC 5中正确上传文件并限制上传的文件类型

Question

我想在ASP.NET MVC 5中实现“上传文件”功能。但我面临两个问题。

问题1 如何强力键入文件上传到模型属性？

问题2 如何仅允许某些文件类型上传？

以下是我的尝试：

模型

    public class Resume
    {
        [Key]
        public int ResumeId { get; set; }

        [StringLength(255)]
        public string FileName { get; set; }

        [StringLength(100)]
        public string ContentType { get; set; }

        public byte[] Content { get; set; }

        [Display(Name = "Date Uploaded")]
        [DisplayFormat(DataFormatString = "{0:d}")]
        public DateTime datetime { get; set; }
   }

查看文件：

@using (Html.BeginForm("Create", "Resume", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
    @Html.AntiForgeryToken()

    <div class="form-horizontal">
        <h4>Resume</h4>
        <hr />
        @Html.ValidationSummary(false, "", new { @class = "text-danger" })
    <div class="form-group">
        @Html.Label("Upload Resume", new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            <input type="file" id="upload" name="uploadedResume" />
        </div>
    </div>
        <div class="form-group">
            <div class="col-md-offset-2 col-md-10">
                <input type="submit" value="Create" class="btn btn-default" />
            </div>
        </div>
    </div>
}

@section Scripts {
    @Scripts.Render("~/bundles/jqueryval")
}

控制器操作

 [HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult Create(Resume resume, HttpPostedFileBase uploadedResume)
    {
             if (ModelState.IsValid)
            {
                if (uploadedResume != null && uploadedResume.ContentLength > 0)
                {
                    var tempresume = new Resume
                    {
                        FileName = System.IO.Path.GetFileName(uploadedResume.FileName),
                        ContentType = uploadedResume.ContentType,
                        datetime = System.DateTime.Now
                    };
                    using (var reader = new System.IO.BinaryReader(uploadedResume.InputStream))
                    {
                        tempresume.Content = reader.ReadBytes(uploadedResume.ContentLength);
                    }
                    _context.Resumes.Add(tempresume);
                }
                _context.SaveChanges();
                return RedirectToAction("ResumeCenter");
    }

上面的代码正在按预期工作，但我无法强力键入文件上传。我也可以使用某种Data Annotation来限制文件上传到pdf only。或FoolProof申请限制。