Microsoft Graph 5.15发送大附件邮件代码报错求助

针对你遇到的两个API调用问题，本质是Microsoft Graph SDK v5与旧版本（如v4）的语法差异，以下是具体修复方案：

1. 修复 Send 方法调用失败问题 #

在Graph SDK v5中，发送邮件的接口已简化，无需链式调用 .Request().PostAsync()，直接调用 SendAsync() 即可：

原错误代码：

await _thisGraphClient.Users[userId].Messages[savedDraft.Id].Send().Request().PostAsync();

修复后：

await _thisGraphClient.Users[userId].Messages[savedDraft.Id].SendAsync();

2. 修复 CreateUploadSession 方法调用失败问题 #

v5中创建附件上传会话的接口结构发生变化，需通过 CreateUploadSession.PostAsync() 传递 CreateAttachmentUploadSessionPostRequestBody 对象，而非直接传入 AttachmentItem：

原错误代码：

var uploadSession = await _thisGraphClient.Users[userId]
    .Messages[savedDraft.Id]
    .Attachments
    .CreateUploadSession(new AttachmentItem
    {
        AttachmentType = AttachmentType.File,
        Name = largeAttachment.Name,
        Size = fileStream.Length,
        ContentType = "application/octet-stream"
    })
    .Request()
    .PostAsync();

修复后：

var uploadSession = await _thisGraphClient.Users[userId]
    .Messages[savedDraft.Id]
    .Attachments
    .CreateUploadSession
    .PostAsync(new CreateAttachmentUploadSessionPostRequestBody
    {
        AttachmentItem = new AttachmentItem
        {
            AttachmentType = AttachmentType.File,
            Name = largeAttachment.Name,
            Size = fileStream.Length,
            ContentType = "application/octet-stream"
        }
    });

完整修复后的代码片段 #

var savedDraft = await _graphClient.Users[userId].Messages.PostAsync(draftMessage);

// Handle large attachments
foreach (var largeAttachment in largeAttachments)
{
    var fileStream = File.OpenRead(largeAttachment.FullName);
    var uploadSession = await _thisGraphClient.Users[userId]
        .Messages[savedDraft.Id]
        .Attachments
        .CreateUploadSession
        .PostAsync(new CreateAttachmentUploadSessionPostRequestBody
        {
            AttachmentItem = new AttachmentItem
            {
                AttachmentType = AttachmentType.File,
                Name = largeAttachment.Name,
                Size = fileStream.Length,
                ContentType = "application/octet-stream"
            }
        });

    int maxSliceSize = 320 * 1024; // 320 KB - Change this to fit your needs
    var fileUploadTask = new LargeFileUploadTask<FileAttachment>(uploadSession, fileStream, maxSliceSize);

    var totalLength = fileStream.Length;
    IProgress<long> progress = new Progress<long>(prog =>
    {
        Console.WriteLine($"Uploaded {prog} bytes of {totalLength} bytes");
    });

    try
    {
        var uploadResult = await fileUploadTask.UploadAsync(progress);
        Console.WriteLine(uploadResult.UploadSucceeded ? "Upload complete" : "Upload failed");
    }
    catch (ServiceException ex)
    {
        Console.WriteLine($"Error uploading: {ex.ToString()}");
    }
    finally
    {
        // 释放文件流，避免资源泄漏
        fileStream.Dispose();
    }
}

// Send the draft
await _thisGraphClient.Users[userId].Messages[savedDraft.Id].SendAsync();

内容的提问来源于stack exchange，提问作者CDVS