Question

最近Microsoft announced可以发送附件大于4MB的电子邮件。根据文档，我们必须先创建草稿，然后进行上传会话，上传附件并最终发送邮件。

我可以使用以下代码创建草稿：

var confidentialClientApplication = ConfidentialClientApplicationBuilder
    .Create(clientId)
    .WithClientSecret(clientSecret)
    .WithTenantId(tenant)
    .Build();

var authenticationProvider = new ClientCredentialProvider(confidentialClientApplication);
var graphClient = new GraphServiceClient(authenticationProvider);

var email = new Message
{
    Body = new ItemBody
    {
      Content = i + " Works fine! " + DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"),
      ContentType = BodyType.Html,
    },
    Subject = "Test" + (j == 0 ? "" : " " + j),
    ToRecipients = recipientList,
    Attachments = att
};

Message draft = await graphClient
    .Users["test@test.onmicrosoft.com"]
    .Messages
    .Request()
    .AddAsync(mail);

但是当我尝试从文档中摘录时：

var attachmentItem = new AttachmentItem
{
    AttachmentType = AttachmentType.File,
    Name = "flower",
    Size = 3483322
};

await graphClient.Me.Messages["AAMkADI5MAAIT3drCAAA="].Attachments
    .CreateUploadSession(attachmentItem)
    .Request()
    .PostAsync();

我得到那些错误：

找不到类型或名称空间名称'AttachmentItem'（您是否缺少using指令或程序集引用？）
名称“ AttachmentType”在当前上下文中不存在
'IMessageAttachmentsCollectionRequestBuilder'不包含'CreateUploadSession'的定义，并且找不到可访问的扩展方法'CreateUploadSession'接受类型为'IMessageAttachmentsCollectionRequestBuilder'的第一个参数（您是否缺少using指令或程序集引用？）

我已经添加了对图库的稳定版本和beta版本（Microsoft.Graph，Microsoft.Graph.Beta）的引用（我以前使用过beta端点），但找不到AttachmentItem。

我已经为AttachmentItem搜索了两个存储库（https://github.com/microsoftgraph/msgraph-sdk-dotnet，https://github.com/microsoftgraph/msgraph-beta-sdk-dotnet），但是没有找到任何内容。

发送带有大附件的邮件是一项新功能（文档发布于2019年10月25日），但根据文档显示，应支持此功能。

文档有误吗？如何创建上传会话和上传附件？我必须手动创建请求吗？还是可以使用Microsoft.Graph库？

我只看到CreateUploadSession的云端硬盘-https://github.com/microsoftgraph/msgraph-sdk-dotnet/search?q=CreateUploadSession&unscoped_q=CreateUploadSession

Answer 1

我不得不四处寻找可行的解决方案。请注意，此示例使用 Microsoft.Graph.Auth nuget，在撰写本文时仍处于预览状态，因此可能会进一步更改。

var tenant = "xxxxxxxxxxxxxxxxxx";
var client = "yyyyyyyyyyyyyyyyyy";
var secret = "xxxxxxxxxxxxxxxxxx";
var senderEmail = "user_email@yourdomainato365.com";

IConfidentialClientApplication confidentialClientApplication = ConfidentialClientApplicationBuilder
    .Create(client)
    .WithTenantId(tenant)
    .WithClientSecret(secret)
    .Build();

ClientCredentialProvider authProvider = new ClientCredentialProvider(confidentialClientApplication);
GraphServiceClient graphClient = new GraphServiceClient(authProvider );

var fileName = "some_huge_file.pdf";
var path = System.IO.Path.Combine(@"D:\Path_To_Your_Files", fileName );
var message = new Message
{
    Subject = "Check out this Attachment?",
    Body = new ItemBody
    {
        ContentType = BodyType.Html,
        Content = "Its <b>awesome</b>!"
    },
    ToRecipients = new List<Recipient>()
    {
        new Recipient
        {
            EmailAddress = new EmailAddress
            {
                Address = "john_doe@gmail.com"
            }
        }
    },
};

var attachmentContentSize = new System.IO.FileInfo(path).Length;

//check to make sure content is below 3mb limit
var isOver3mb = attachmentContentSize > (1024*1024*3);

//if below our limit, send directly.
if( isOver3mb == false )
{
    message.Attachments = new MessageAttachmentsCollectionPage()
    {
        new FileAttachment{ Name = fileName, ContentBytes = System.IO.File.ReadAllBytes(path) }     
    };
    
    await graphClient.Users[senderEmail].SendMail(message, true).Request().PostAsync();
}
else
{
    //first create an email draft
    var msgResult = await graphClient.Users[senderEmail].Messages
                            .Request()
                            .AddAsync(message);

    var attachmentItem = new AttachmentItem
    {
        AttachmentType = AttachmentType.File,
        Name = fileName,
        Size = attachmentContentSize,       
    };

    //initiate the upload session for large files (note that this example doesn't handle multiple attachment).
    var uploadSession = await graphClient.Users[senderEmail].Messages[msgResult.Id].Attachments
                                                            .CreateUploadSession(attachmentItem)
                                                            .Request()
                                                            .PostAsync();
     
    var maxChunkSize = 1024 * 320;      
    var allBytes = System.IO.File.ReadAllBytes(path);
        
    using( var stream =  new MemoryStream ( allBytes ) )
    {
        stream.Position = 0;
        LargeFileUploadTask<FileAttachment> largeFileUploadTask = new LargeFileUploadTask<FileAttachment>(uploadSession, stream, maxChunkSize);

        await largeFileUploadTask.UploadAsync();
    }
    //once uploaded, sends out the email from the Draft folder
    await graphClient.Users[senderEmail].Messages[msgResult.Id].Send().Request().PostAsync();
}

Answer 2

此功能在Preview（aka Beta）中。由于这些API和资源仅存在于Graph Beta中，因此您不能使用AWS Systems Manager库的GA版本。您需要使用该库的Microsoft.Graph版本。

使用MS Graph库发送带有大型附件的电子邮件

2 个答案: