Question

通过System.Net.Mail.Attachment向Outlook.MailItem.Attachments添加新的Attachments.Add()会产生System.ArgumentException: 'Sorry, something went wrong. You may want to try again.'

尝试将以Base64编码的JPEG图像添加为Outlook中邮件项目的附件。我将编码的图像存储为变量，将其转换为内存流，然后转换为附件。

public void CreateMessageWithAttachment() {
    Outlook.MailItem mailIttem = thisAddIn.Application.CreateItem(Outlook.OlItemType.olMailItem);
    string base64Attachment = "/...base64 gibberish";
    MemoryStream ms = new MemoryStream(Convert.FromBase64String(base64Attachment));
    ContentType ct = new ContentType(MediaTypeNames.Image.Jpeg);
    Attachment attachment = new Attachment(ms, ct);

    attachment.ContentDisposition.FileName = "look_at_dis.jpg";
    mailIttem.Subject = "Test e-mail message with attachment";
    mailIttem.To = "friend@company.com";
    mailIttem.Body = "This message has been generated programmatically";
    mailIttem.Attachments.Add(attachment); // This raises "Sorry..." expression
    mailIttem.Display(true);
}

提高System.ArgumentException: 'Sorry, something went wrong. You may want to try again.'，这什么也没告诉我：-/

Answer 1

MailItem.Attachments.Add仅允许传递字符串（文件的标准路径）或另一个Outlook项目（例如MailItem）作为参数。

在扩展MAPI级别（仅C ++或Delphi）上，仅使用IStream（您应该使用PR_ATTACH_DATA_BIN以IStream的形式打开IAttach::OpenProperty。如果可以选择使用Redemption（我是作者），则允许传递url，文件名，另一个Outlook项目，IStream或IStorage COM界面，另一个附件（{ {1}}或Outlook.Attachment或Redemption.RDOAttachment MAPI接口）或RDOMail。Attachments。IAttach

Answer 2

在将内存流附加到消息之前，我相信您必须将其位置重置为零：

MemoryStream ms = new MemoryStream(Convert.FromBase64String(base64Attachment));
ms.Position = 0; // important
ContentType ct = new ContentType(MediaTypeNames.Image.Jpeg);
Attachment attachment = new Attachment(ms, ct);
// etc

Answer 3

Official docs给我的印象是Attachments.Add仅应真正用于文件路径，因此将MemoryStream保存到临时文件并附加它可以解决问题。

string tempFilePath = Path.GetTempPath() + "look_at_dis.jpg";
FileStream fs = new FileStream(tempFilePath, FileMode.Create);

ms.CopyTo(fs);
fs.Close();

mailIttem.Attachments.Add(tempFilePath, Outlook.OlAttachmentType.olByValue, 1, "look_at_dis.jpg");

如何从内存中制作Outlook邮件附件？

3 个答案: