使用 REST API 下载 Outlook 附件

Question

我正在处理与Outlook Mail API相关的项目。我想下载电子邮件的附件。文档说我可以"获取"附件，它们在 json 响应中返回不同的参数，但我很好奇我必须将哪个转换为什么，以便将实际附件保存到文件系统中。

http://msdn.microsoft.com/office/office365/api/mail-rest-operations#Getattachments

谢谢。

Answer 1

根据文档，https://outlook.office.com/api/v2.0/me/messages/{message_id}/attachments返回一个附件集合，其中包含单个附件的标识符：

{
    "@odata.context": "https://outlook.office.com/api/v2.0/$metadata#Me/Messages('AAMkAGI2THVSAAA%3D')/Attachments(Name)",
    "value": [
        {
            "@odata.type": "#Microsoft.OutlookServices.FileAttachment",
            "@odata.id": "https://outlook.office.com/api/v2.0/Users('ddfcd489-628b-40d7-b48b-57002df800e5@1717622f-1d94-4d0c-9d74-709fad664b77')/Messages('AAMkAGI2THVSAAA=')/Attachments('AAMkAGI2j4kShdM=')",
            "Id": "AAMkAGI2j4kShdM=",
            "Name": "minutes.docx"
        }
    ] }

现在，您可以循环访问此列表并使用此 API 获取单个附件 - https://outlook.office.com/api/v2.0/me/messages/{message_id}/attachments/{attachment_id}其中attachment_id是从上述 API 返回的标识符。

响应将是：

{
    "@odata.context": "https://outlook.office.com/api/v2.0/$metadata#Me/Messages('AAMkAGI2THVSAAA%3D')/Attachments/$entity",
    "@odata.type": "#Microsoft.OutlookServices.FileAttachment",
    "@odata.id": "https://outlook.office.com/api/v2.0/Users('ddfcd489-628b-40d7-b48b-57002df800e5@1717622f-1d94-4d0c-9d74-709fad664b77')/Messages('AAMkAGI2THVSAAA=')/Attachments('AAMkAGI2j4kShdM=')",
    "Id": "AAMkAGI2j4kShdM=",
    "LastModifiedDateTime": "2014-10-20T00:41:52Z",
    "Name": "minutes.docx",
    "ContentType": "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
    "Size": 11585,
    "IsInline": false,
    "ContentId": null,
    "ContentLocation": null,
    "ContentBytes": "UEsDBBQABgAIAAAAIQDCAAA4KQAAAAA=" }

现在，您可以使用 ContentBytes 和 contentType 在本地保存此附件。此外，附件可以是ItemAttachments的，也可以是FileAttachments的。在Google上搜索更多内容肯定会引导您找到一些示例代码，该代码显示了如何下载它们。但这应该给你一个想法。

你可以检查这个：

public static void GetAttachmentsFromEmail(ExchangeService service, ItemId itemId)
        {
            // Bind to an existing message item and retrieve the attachments collection.
            // This method results in an GetItem call to EWS.
            EmailMessage message = EmailMessage.Bind(service, itemId, new PropertySet(ItemSchema.Attachments));
            // Iterate through the attachments collection and load each attachment.
            foreach (Attachment attachment in message.Attachments)
            {
                if (attachment is FileAttachment)
                {
                    FileAttachment fileAttachment = attachment as FileAttachment;
                    // Load the attachment into a file.
                    // This call results in a GetAttachment call to EWS.
                    fileAttachment.Load("C:\temp\" + fileAttachment.Name);
                    Console.WriteLine("File attachment name: " + fileAttachment.Name);
                }
                else // Attachment is an item attachment.
                {
                    ItemAttachment itemAttachment = attachment as ItemAttachment;
                    // Load attachment into memory and write out the subject.
                    // This does not save the file like it does with a file attachment.
                    // This call results in a GetAttachment call to EWS.
                    itemAttachment.Load();
                    Console.WriteLine("Item attachment name: " + itemAttachment.Name);
                }
            }
        }