Question

我开发了成功将电子邮件附件下载到本地电脑的方法我也必须将它们从电子邮件直接下载到ftp服务器我试图实现我认为应该工作的功能。
当我成功获取FileAttachment对象时，我尝试使用其属性ContentLocation来获取附件URL 然后我将该URL传递给webClient.DownloadString（）方法但不幸的是，属性ContentLocation始终为空所以我在这行代码中有一个例外。
以下是我的方法的完整列表和评论：

    var service = new ExchangeService(ExchangeVersion.Exchange2013);
    service.Credentials = new NetworkCredential(serviceUserName, servicePassword);

    service.Url = new Uri(serviceUrl);
    ServicePointManager.ServerCertificateValidationCallback = delegate { return true; };
    var path = System.IO.Directory.CreateDirectory(Path.Combine(applicationPath, name));

    //Filters
    List<SearchFilter> searchANDFilterCollection = new List<SearchFilter>();
    searchANDFilterCollection.Add(new SearchFilter.IsEqualTo(EmailMessageSchema.IsRead, false));
    searchANDFilterCollection.Add(new SearchFilter.IsEqualTo(EmailMessageSchema.From, new EmailAddress(email)));
    SearchFilter sf =
        new SearchFilter.SearchFilterCollection(LogicalOperator.And, searchANDFilterCollection.ToArray());
    FindItemsResults<Item> findResults;
    ItemView view = new ItemView(10);
    do
    {
        findResults = service.FindItems(WellKnownFolderName.Inbox, sf, view);
        if (findResults != null && findResults.Items != null && findResults.Items.Count > 0)
            foreach (EmailMessage item in findResults)
            {
                var message = EmailMessage.Bind(service, item.Id, new PropertySet(BasePropertySet.IdOnly, ItemSchema.Attachments, ItemSchema.HasAttachments));
                foreach (Attachment attachment in message.Attachments)
                {
                    if (attachment is FileAttachment)
                    {
                        if (attachment.Name.Contains(".xlsx") || attachment.Name.Contains(".xlsb") || attachment.Name.Contains(".xls") || attachment.Name.Contains(".csv"))
                        {
                            var fileAttachment = attachment as FileAttachment;

                            //Download to ftp
                            if (isSaveToFTP)
                            {
                                var webClient = new WebClient();
                                string readHtml = webClient.DownloadString(fileAttachment.ContentLocation);
                                byte[] buffer = Encoding.Default.GetBytes(readHtml);

                                WebRequest makeDirectory = WebRequest.Create(Path.Combine(ftpAddress, name));
                                makeDirectory.Method = WebRequestMethods.Ftp.MakeDirectory;
                                makeDirectory.Credentials = new NetworkCredential(username, password);
                                WebRequest uploadFile = WebRequest.Create(ftpAddress + name + "/" + fileAttachment.Name);
                                uploadFile.Method = WebRequestMethods.Ftp.UploadFile;
                                uploadFile.Credentials = new NetworkCredential(username, password);
                                Stream reqStream = uploadFile.GetRequestStream();
                                reqStream.Write(buffer, 0, buffer.Length);
                                reqStream.Close();
                            }
                            //Download to pc
                            else fileAttachment.Load(String.Format(@"{0}\{1}", path, fileAttachment.Name));
                        }
                    }
                    //fileAttachment.Load(path.Name);
                }
            }


        // mark email as read
        item.IsRead = true;
        item.Update(ConflictResolutionMode.AlwaysOverwrite);
      }
    }
    while (findResults.MoreAvailable);

我应该改变什么来完成这项工作？或者还有其他解决方案吗？

Answer 1

我认为ContentLocation依赖于消息创建者。我认为您要做的是使用Load(Stream)将内容拉入流中，然后根据isSaveToFTP标志选择在哪里写入该流。

Answer 2

以下是基于richrdsonmarkj答案的解决方案：

 if (isSaveToFTP)
        {
            using (WebClient webClient = new WebClient())
            {
                Stream stream = new MemoryStream();
                fileAttachment.Load(stream);
                using (var reader = new StreamReader(stream))
                {
                    byte[] buffer = Encoding.Default.GetBytes(reader.ReadToEnd());
                    WebRequest uploadFile = WebRequest.Create(ftpAddress + name + "/" + fileAttachment.Name);
                    uploadFile.Method = WebRequestMethods.Ftp.UploadFile;
                    uploadFile.Credentials = new NetworkCredential(username, password);
                    Stream reqStream = uploadFile.GetRequestStream();
                    reqStream.Write(buffer, 0, buffer.Length);
                    reqStream.Close();
                }
            }

通过电子邮件将附件直接下载到ftp服务器

2 个答案: