Question

我正在使用的系统有一个要求，即将刚发送的电子邮件的MimeContent存储在本地数据库中。我对Exchange的工作方式的理解是，它将在服务器上创建MimeContent，除非查询该刚刚发送的消息，否则我将无法访问它。

所以，我采取的步骤是：

-发送电子邮件并获取Id

message.SendAndSaveCopy();
return message.Id.UniqueId;

-使用新ID获取刚刚发送的EmailMessage

ExchangeService exchangeService = ExchangeService;

var properties = new List<PropertyDefinitionBase>
{
    ItemSchema.MimeContent
};

EmailMessage message = EmailMessage.Bind(exchangeService, new ItemId(messageId), new PropertySet(BasePropertySet.IdOnly, properties));

当此代码不间断运行时，它将起作用。返回的Id仍然有效（消息在发件箱文件夹中），我得到了结果。但是，如果我放慢速度一秒钟，则该ID不再有效（我想它现在已移至已发送的文件夹中）。

我不能这样保留它，因为不能保证我会及时回到服务器来检索带有该Id的消息。

如果有一种解决方案可以使我不必再次向该服务查询消息，那将会很不错。但是，如果没有，是否可以使用Id和ChangeKey来获取刚刚发送的电子邮件？

Answer 1

最终回答了我自己的问题。为此，我在自己控制的每封电子邮件中添加了一个自定义属性。然后，我使用相同的值来搜索电子邮件。我在查询之间的文件夹之间移动电子邮件时遇到了一些问题，但现在已进行排序。

将其定义在某个地方，我将其放在我的EmailProvider类中：

private readonly PropertyDefinitionBase _TempEmailId = new ExtendedPropertyDefinition(DefaultExtendedPropertySet.PublicStrings, "TempEmailId", MapiPropertyType.String);

然后在发送电子邮件之前将其添加：

string messageId = null;
if (getTempId)
{
    messageId = Guid.NewGuid().ToString();
    message.SetExtendedProperty((ExtendedPropertyDefinition) _TempEmailId, messageId);
}

message.SendAndSaveCopy();
return messageId;

最后，使用messageId获得MimeContent（或您想要的其他任何属性）：

/// <summary>
/// Get the mime content for an email just sent
/// </summary>
/// <param name="messageId"></param>
/// <returns></returns>
public byte[] GetJustSentMimeContent(string messageId)
{
    ExchangeService exchangeService = ExchangeService;

    // Use the following search filter to get mail with TempEmailId set to what we just got
    var searchCriteria = new SearchFilter.IsEqualTo(_TempEmailId, messageId);

    var itemView = new ItemView(1) {PropertySet = new PropertySet(BasePropertySet.IdOnly)};

    byte[] GetMimeContent(WellKnownFolderName folder)
    {
        var items = exchangeService.FindItems(folder, searchCriteria, itemView);

        if (items.TotalCount > 0)
        {
            // if it's still in there, try and load the properties for it
            exchangeService.LoadPropertiesForItems(items,
                new PropertySet(BasePropertySet.IdOnly,
                    ItemSchema.MimeContent));

            var emailMessage = (EmailMessage) items.First();

            // if the content has been loaded, return it
            if (emailMessage.MimeContent != null)
                return emailMessage.MimeContent.Content;
        }

        return null;
    }

    // check the drafts folder to see if it's still in there
    var mimeContent = GetMimeContent(WellKnownFolderName.Drafts);

    if (mimeContent != null)
        return mimeContent;

    // if at this point, either: 
    // - email was moved to SentItems before the first search was done
    // - or email was found in Drafts but then moved to SentItems but before the MimeContent could be loaded. Need to restart the process and find the email in SentItems instead

    // should be in here (sentItems) now, try and load the properties for it
    return GetMimeContent(WellKnownFolderName.SentItems);
}

C＃Exchange Web服务-发送并立即检索已发送的消息

1 个答案: