0

我在 VB.net 项目上的附件内存流有一个常见的问题。我正在调用一个共享成员(SendMail),传入一个客户对象和一个要作为附件发送的文件的内存流。在“SendMail”中,它调用两个独立的函数来准备一封普通电子邮件和另一个用于数字签名的电子邮件。我遇到的问题是我收到了完美的数字签名电子邮件,但是,在普通电子邮件中,附件是空白的,并且附加了文件名(64 B)。如果我禁用数字签名的部分常规邮件工作正常。看起来内存流在数字签名中的某个地方发生了变化。

这是他我打电话的方式

mailHelper.SendMail(cust, attachment)

使用 mailHelper 类

Public Shared Sub SendEmail(ByVal cust As Customer, ByVal attachment As MemoryStream)

  Dim messages As New List(Of MailMessage)
  messages.Add(CreateUnSignedMail(cust,attachment)
  messages.Add(CreateSignedMail(cust,attachment)
  SendSMTPMail(messages)
End Sub

Private Shared Function CreateUnSignedMail(ByVal cust As Customer, ByVal attachment As MemoryStream) As MailMessage

Dim eMail As New MailMessage()
        With eMail
            .//Normal properties set (like to, from etc)

            .Attachments.Add(New Attachment(attachment, "someFilename.doc")
        End With
        Return eMail
End Function

Private Shared Function CreateSignedMail(ByVal cust As Customer, ByVal attachment As MemoryStream) As MailMessage

Dim eMail As New SecureMailMessage()
        With eMail
            .//Normal properties set (like to, from etc)

            .Attachments.Add(New  SecureAttachment(attachment, "someFilename.doc")
        End With
        Return eMail
End Function


Private Shared Sub SendSMTPMail(ByVal messages As List(Of System.Net.Mail.MailMessage))
        Dim smtp As New SmtpClient("myServer")
        Try
            With smtp
                .//Additional properties set

                For Each email In messages
                    .Send(email)
                Next

            End With

        Catch ex As Exception
            //Log error to file.
            Logger.Log.Error("SMTP Error", ex)
            Throw
        End Try
End Sub

但是,如果我尝试以下方法,它可以正常工作,这是正确的解决方案吗?

messages.Add(SendUnSignedMail(cust, New MemoryStream(attachment.ToArray())))
messages.Add(SendSignedMail(cust, New MemoryStream(attachment.ToArray())))
4

1 回答 1

0

假设您已经解决了这个问题,因为得到答案的延迟,但无论如何这是我的尝试......

创建附件有很多重载,它们都不符合您初始化附件的方式。

创建附件时,第二个参数需要为 NULL 或标识附件的有效 MIME 类型。

希望这可以帮助。

于 2011-06-07T00:09:01.433 回答