EWS API:如何检索附件的修改日期

// 创建ExchangeService对象并进行身份验证
ExchangeService service = new ExchangeService(ExchangeVersion.Exchange2010_SP2);
service.Credentials = new NetworkCredential("username", "password");

// 设置Exchange服务器的URL
service.Url = new Uri("https://example.com/EWS/Exchange.asmx");

// 获取邮件的附件
EmailMessage email = EmailMessage.Bind(service, new ItemId("emailId"));
email.Load(new PropertySet(BasePropertySet.FirstClassProperties, EmailMessageSchema.Attachments));

foreach (Attachment attachment in email.Attachments)
{
    // 检查附件类型是否为文件附件
    if (attachment is FileAttachment)
    {
        FileAttachment fileAttachment = attachment as FileAttachment;
        
        // 获取附件的修改日期
        DateTime modifiedDate = fileAttachment.LastModifiedTime;
        
        // 在控制台输出修改日期
        Console.WriteLine("Attachment Modified Date: " + modifiedDate.ToString());
    }
}