用REST API下载Outlook附件？[英] Downloading Outlook attachments with REST API?

问题描述

Im working on a project that is related to the Outlook Mail API. I want to download the attachments an email has. The documantation says that i can "get" the attachments, and they return different parameters in a json response, but im curious to know which one i have to convert to what, to get the actual attachment saved on to the filesystem.

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

Thank you.

推荐答案

As per the documentation, https://outlook.office.com/api/v2.0/me/messages/{message_id}/attachments returns a collection of attachments which contains an identifier for the individual attachment:

{
    "@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"
        }
    ] }

Now, you can iterate through this list and fetch individual attachment using this API - https://outlook.office.com/api/v2.0/me/messages/{message_id}/attachments/{attachment_id} where attachment_id is the identifier returned from above API.

The response will be:

{
    "@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=" }

Now, you can save this attachment locally using ContentBytes and contentType. Moreover, attachments could be ItemAttachments or FileAttachments. Searching more on Google will definitely lead you to some sample code which shows how to download them. But this should give you an idea.

You can check this:

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);
                }
            }
        }