如何使用 EWS Managed API 按 ID 获取附件？

Question

是否可以直接使用 EWS Managed API 获取附件，而无需先获取其包含的 EmailMessage？

类似于：

FileAttachment attach = FileAttachment.Bind(ewsService, attachId);

我找不到任何方法。

Answer 1

您可以使用 ExchangeService Class https://msdn.microsoft.com/en-us/library/office/dn600509(v=exchg.80).aspx 的 GetAttachments 方法，这允许您将一个或多个 GetAttachment 请求一起批处理，例如：

     FindItemsResults<Item> fItems = service.FindItems(WellKnownFolderName.Inbox,new ItemView(10));
    PropertySet psSet = new PropertySet(BasePropertySet.FirstClassProperties);
    service.LoadPropertiesForItems(fItems.Items, psSet);
    List<Attachment> atAttachmentsList = new List<Attachment>();
    foreach(Item ibItem in fItems.Items){
        foreach(Attachment at in ibItem.Attachments){
            atAttachmentsList.Add(at);
        }
    }
    ServiceResponseCollection<GetAttachmentResponse> gaResponses = service.GetAttachments(atAttachmentsList.ToArray(), BodyType.HTML, null);
    foreach (GetAttachmentResponse gaResp in gaResponses)
    {
        if (gaResp.Result == ServiceResult.Success)
        {
            if (gaResp.Attachment is FileAttachment)
            {
                Console.WriteLine("File Attachment");
            }
            if (gaResp.Attachment is ItemAttachment)
            {
                Console.WriteLine("Item Attachment");
            }
        }
    }