Question

我使用EWS托管API下载电子邮件，我设法自行下载电子邮件。我可以通过EmailMessage.From.Name和EmailMessage.Subject验证它是否是正确的电子邮件。

然而，当在Outlook中查看它时，它有一个附件，但.Net对象的EmailMessage.HasAttachments设置为false，而EmailMessage.Attachments.Count等于零。

为什么我能够在Outlook中看到附件，而不是通过.Net对象？

我的代码如下：

using System;
using System.Collections.Generic;
using System.Configuration;
using System.IO;
using System.IO.Compression;
using System.Linq;
using Microsoft.Exchange.WebServices.Data;

namespace CiscoPrimeInfrastructureDataAccess
{
    public static class EmailFetcher
    {
        private const string _EMAIL = @"foo@bar.com";
        private const string _USERNAME = "foo";
        private const string _PASSWORD = "bar123";
        private const string _DOMAIN = "bar";
        private const string _SUBJECT = "foobar subject";

        public static string GetCurrentPrimeCsv()
        {
            string inboxFolder = ConfigurationManager.AppSettings["Inbox"];

            if (!File.Exists(inboxFolder))
                File.Create(inboxFolder);

            var service = CreateExchangeService();

            var newestInventoryReport = GetNewestInventoryEmail(service);

            Console.WriteLine("From: {0}{1}Subject: {2}{3}Number of Attachments: {4}", newestInventoryReport.From.Name, Environment.NewLine, newestInventoryReport.Subject, Environment.NewLine, newestInventoryReport.Attachments.Count);

            FileAttachment attachment = newestInventoryReport.Attachments[0] as FileAttachment;

            string guid = Guid.NewGuid().ToString();

            string downloadFilePath = Path.Combine(inboxFolder, guid + "_" + attachment.FileName);
            string extractedFilePath = Path.Combine(inboxFolder, guid + "_extracted.csv");

            attachment.Load(Path.Combine(downloadFilePath));

            ZipFile.ExtractToDirectory(downloadFilePath, extractedFilePath);

            string csv = String.Empty;

            using (var reader = new StreamReader(extractedFilePath))
            {
                csv = reader.ReadToEnd();
            }

            return csv;
        }



        private static ExchangeService CreateExchangeService()
        {
            ExchangeService service = new ExchangeService(ExchangeVersion.Exchange2007_SP1);
            service.Credentials = new WebCredentials(_USERNAME, _PASSWORD, _DOMAIN);

            service.AutodiscoverUrl(_EMAIL);

            return service;
        }


        private static EmailMessage GetNewestInventoryEmail(ExchangeService service)
        {
            var firstSeveralEmails = GetFirstSeveralEmails(service);

            EmailMessage newestEmail = null;

            foreach (var email in firstSeveralEmails)
            {
                if (email.Subject.Contains(_SUBJECT))
                {
                    if (newestEmail == null || email.DateTimeReceived > newestEmail.DateTimeReceived)
                    {
                        newestEmail = email;
                    }
                }
            }

            return newestEmail;
        }

        private static IEnumerable<EmailMessage> GetFirstSeveralEmails(ExchangeService service)
        {
            Mailbox mailbox = new Mailbox(_EMAIL);
            FolderId inboxFolderId = new FolderId(WellKnownFolderName.Inbox, mailbox);

            FindItemsResults<Item> findItemsResults = service.FindItems(inboxFolderId, new ItemView(128));

            return findItemsResults.OfType<EmailMessage>().Select(findEmailResult => findEmailResult as EmailMessage).ToList();
        }
    }
}

Answer 1

我还没有使用过EWS，所以这可能是错误的。

我已经查看了电子邮件的正文。附件实际上在身体中传输，通常作为base64编码的字符串，在编码数据之前和之后使用mime标记来区分不同的文件。 EWS可能没有在您获得的对象中处理这些内容。有可能的是，当您获得一个项目并投射到EnailMessage时，EmailMessage还没有完全处理到例如提取附件。请注意，文档说：

Use the Bind(ExchangeService, ItemId) method to bind to an existing e-mail message on the Exchange server.

这可能会有所帮助。

C＃下载电子邮件 - 未找到附件

1 个答案: