无法将文件从API上传到Sharepoint

Question

此picture介绍了我所做的事情。问题是，当我尝试在Sharepoint中打开文件时，它会引发一个popup。然后，当我单击“确定”时，它会给我this。单击恢复时，我可以看到内容。我该如何处理这些弹出窗口？

这是我的应用程序部分（TemplateModel包含我尝试发送到API的HttpPostedFileBase FileUpload属性）：

    [HttpPost]
    public ActionResult CreateTemplate(TemplateModel template)
    {
        HttpResponseMessage result = new HttpResponseMessage();

        if (TemplateModel.GetAll().Count != 0)
            template.ID = TemplateModel.GetAll().Max(t => t.ID) + 1;
        else
            template.ID = 1;

        #region posting to sharepoint
        string URI = "http://localhost:50073/api/template/PostTemplate";

        var item = template.FileUpload.InputStream.Length;

        if (Request.Files.Count > 0)
        {
            using (HttpClient client = new HttpClient())
            {
                using (var content = new MultipartFormDataContent())
                {
                    byte[] fileBytes = new byte[template.FileUpload.InputStream.Length + 1];
                    template.FileUpload.InputStream.Read(fileBytes, 0, fileBytes.Length);
                    var fileContent = new ByteArrayContent(fileBytes);
                    fileContent.Headers.ContentDisposition
                        = new ContentDispositionHeaderValue("attachment") { FileName = template.ID.ToString() };
                    fileContent.Headers.ContentType =
                        new MediaTypeHeaderValue("application/octet-stream");
                    content.Add(fileContent);

                    content.Headers.ContentDisposition = new ContentDispositionHeaderValue("Content-Dsposition")
                    {
                        FileName = template.ID.ToString(),
                    };
                    result = client.PostAsync(URI, content).Result;
                }
            }
        }
        #endregion

        if (result.StatusCode != HttpStatusCode.OK)
            return RedirectToAction("Templates");

        template.Create();
        return RedirectToAction("Templates");
    }

这是API部分。 API从Request.Content接收上传的文件：

[HttpPost]
    public HttpResponseMessage PostTemplate()
    {
        var requestContent = Request.Content;

        string id = Request.Content.Headers.ContentDisposition.FileName;
        MemoryStream stream = new MemoryStream();
        requestContent.CopyToAsync(stream);

        byte[] data = stream.ToArray();

        if (!_sharepoint.SubFolderExistsInFolder("/Documents/Templates"))
            Request.CreateErrorResponse(HttpStatusCode.InternalServerError, "Root of templates folder doesn't exist");

        try
        {
            _sharepoint.PostFile(new SP.UploadProperties
            {
                Stream = stream,
                FileName = string.Format("{0}.docx", id),
                ServerURL = "/Documents/Templates/" + string.Format("{0}.docx", id) /*+ postedFile.FileName*/
            }, data);
            return Request.CreateResponse(HttpStatusCode.OK);
        }
        catch (Exception e)
        {
            return Request.CreateErrorResponse(HttpStatusCode.InternalServerError, e.ToString());
        }
    }

如您所见，我将requestContent转换为MemoryStream以获得字节数组（byte []数据）。这是_sharepoint.PostMethod方法定义，用于将byte []作为CSOM文件上传到Sharepoint特定文件夹：

public void PostFile(UploadProperties properties, byte[] byteArray=null)
        {
            ClientContext ctx = GetContextObject();

            List docLib = ctx.Web.Lists.GetByTitle("Documents");
            ctx.Load(docLib);
            ctx.ExecuteQuery();

            FileCreationInformation createFile = new FileCreationInformation
            {
                Url = RelativeURL + properties.ServerURL,
                Content = byteArray,
                Overwrite = true
            };

            try
            {
                Microsoft.SharePoint.Client.File addedFile = docLib.RootFolder.Files.Add(createFile);
                ctx.Load(addedFile);
                ctx.ExecuteQuery();
                docLib.Update();
            }
            catch (Exception e)
            {
                var test = e.ToString();
            }
}