我想在数据库的ASP.NET MVC中上传和下载文件。

Question

我想在ASP.NET MVC中上传和下载文件。

这是我在控制器中的操作方法。当我调试文件为null时。我要去哪里错了？

public ActionResult UploadDocument(CompanyViewModel  model,HttpPostedFileBase FileUpload)
{
    var userId = User.Identity.GetUserId<int>();

    if (model.File != null && model.File.ContentLength > 0)
    {
        string fileExtension = System.IO.Path.GetExtension(model.File.FileName);

        if (fileExtension == ".doc" || fileExtension == ".docx" || fileExtension == ".xlsx" || fileExtension == ".xls" || fileExtension == ".pdf" || fileExtension == ".jpeg" || fileExtension == ".jpg")
        {
            var file = model.File;
            var fileName = System.IO.Path.GetFileNameWithoutExtension(model.File.FileName);
            var contentLength = file.ContentLength;
            var contentType = file.ContentType;

            var document = new CompanyDocument();

            document.CreatedDate = System.DateTime.Now;
            byte[] byteData = new byte[file.InputStream.Length];

            file.InputStream.Read(byteData, 0, byteData.Length);

            document.FileData = byteData;
            document.FileName = fileName;
            document.CategoryId = model.CategoryId;
            document.ContentType = contentType;
            document.CreatedDate = DateTime.Now;

            _CompanyDocumentsRepository.AddOrUpdate(document);
        }
        else
        {
            TempData["ErrorMessage"] = "Only word, excel, pdf, jpg files are allowed to upload.";
            return Json(new { msgstatus = false, msg = "Only word, excel, pdf, jpg files are allowed to upload." }, JsonRequestBehavior.AllowGet);
        }
    }

    return Json(new { msgstatus = true, msg = "Document uploaded successfully." }, JsonRequestBehavior.AllowGet);
}

我的观点：

@model BusSchedulingSystem.Web.ViewModels.CompanyViewModel

@using(Html.BeginForm("UploadDocument","Company", null, FormMethod.Post, new { enctype="multipart/form-data"}))
{
    if (Model != null && Model.Id > 0)
    {
                    @Html.HiddenFor(m => m.Id)
                }
                @Html.AntiForgeryToken()


                    <div class="row wrapper border-bottom white-bg page-heading">
            <div class="ibox float-e-margins">
                <div class="row">
                    <div class="col-sm-6">
                        <h4 class="section-title">Upload File</h4>
                        <div class="ibox-content">
                            <div class="form-group">
                                @Html.LabelFor(m => m.FileName)

                                <input type='file' name="FileUpload" id="File">
                                <input type="submit" value="Upload" />
                                @Html.ValidationMessageFor(model => model.FileName, "", new { @class = "text-danger" })
                            </div>

                            <div class="form-group">

                            </div>
                        </div>
                    </div>
                </div>
            </div>
        </div>

}