Visual Basic 重载解析失败，因为无法调用可访问的“New”，错误

Question

我从这个问题得到了这个代码：

使用内存流生成 PDF 文件 system.net.mail.attachment

帮助我在内存中创建电子邮件附件。

Imports System.IO
Imports System.Net.Mail
Imports System.Text.ASCIIEncoding
Imports System.net.Mime

Public Sub SendMail(ByVal att As String, Optional ByVal filename As String _
    = "Attachment.csv")

    Dim sendMail As New SmtpClient
    Dim mail As New MailMessage

    Using MemoryStream = New MemoryStream

        If att.Length <> 0 Then

            Dim data As Byte() = ASCII.GetBytes(att)

            MemoryStream.Write(data, 0, data.Length)
            MemoryStream.Seek(0, SeekOrigin.Begin)
            MemoryStream.Position = 0

            Dim content As New Net.Mime.ContentType()

            content.MediaType = MediaTypeNames.Application.Octet
            content.Name = filename

            Dim Attach As Attachment
            Attach = New Attachment(MemoryStream, content)
            mail.Attachments.Add(Attach)
        End If

        sendMail.DeliveryMethod = SmtpDeliveryMethod.Network
        sendMail.Host = "SERVER"
        sendMail.UseDefaultCredentials = False

        sendMail.Credentials = New System.Net.NetworkCredential("UN", "PW")
        sendMail.Send(mail)
    End Using
End Sub

我收到此错误：

重载解析失败，因为在没有缩小转换的情况下无法调用可访问的“New”：

'Public Sub New(contentStream As System.IO.Stream, contentType As System.Net.Mime.ContentType)'：参数匹配参数'contentStream'从'Object'缩小到'System.IO.Stream'。

'Public Sub New(fileName As String, contentType As System.Net.Mime.ContentType)'：参数匹配参数'fileName'从'Object'缩小到'String'。

Dim Attach As Attachment
Attach = New Attachment(MemoryStream, content)

在这条线上。

我怎样才能解决这个问题？

Answer 1

或使用这个

Using MemoryStream As MemoryStream = new MemoryStream()