如何将Outlook.MailItem附件转换为输入流？

Question

我想在Outlook帐户中收到电子邮件时将附件保存到AWS桶中。 我试过HttpPostedFileBase ，它有InputStream属性。

我尝试过如下

//successfully saving 'HttpPostedFileBase' files

using (IAmazonS3 s3client = new AmazonS3Client(_awsAccessKey, _awsSecretKey, RegionEndpoint.USEast1)) {
    PutObjectRequest putObjectRequest = new PutObjectRequest {
        BucketName = _bucketName,
        CannedACL = S3CannedACL.PublicRead,
        Key = string.Format("uploads/" + AssignedTaskId.ToString() + "/" + Path.GetFileName(postedFile.FileName)),
        InputStream = postedFile.InputStream
    };
    s3client.PutObject(putObjectRequest);
}

//but cannot get from Outlook.MailItem attachments

Outlook.MailItem newEmail = null;
foreach (object collectionItem in inBoxItems) {
    newEmail = collectionItem as Outlook.MailItem;
}
using (IAmazonS3 s3client = new AmazonS3Client(_awsAccessKey, _awsSecretKey, RegionEndpoint.USEast1)) {
    PutObjectRequest putObjectRequest = new PutObjectRequest {
        BucketName = _bucketName,
        CannedACL = S3CannedACL.PublicRead,
        Key = string.Format("uploads/{0}", newEmail.Attachments[i].FileName),
        InputStream = newEmail.Attachments[i].InputStream
    };
    s3client.PutObject(putObjectRequest);
}
}

得到错误：

'Attachment'不包含'InputStream'的定义，并且没有可访问的扩展方法'InputStream'接受类型'Attachment'的第一个参数（你是否缺少using指令或汇编引用？）

Answer 1

Outlook对象模型不提供任何属性。 相反，您可以访问低级属性：

 const string PR_ATTACH_DATA_BIN = "http://schemas.microsoft.com/mapi/proptag/0x37010102";

 Outlook.Attachment attachment = mail.Attachments[0];  

 // Retrieve the attachment as a byte array
 var attachmentData = attachment.PropertyAccessor.GetProperty(PR_ATTACH_DATA_BIN);

另一种选择是将附件（请参阅Attachment.SaveAsFile ）保存到文件，然后将该文件作为字节流打开。