vb.net Visual Basic 重载解析失败，因为无法调用可访问的“New”，错误
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Visual Basic Overload resolution failed because no accessible 'New' can be called, error
提问by UrsulRosu
I have this code from this question:
我有这个问题的代码：
Generate a PDF file as system.net.mail.attachment using Memory Stream
使用内存流生成一个 PDF 文件作为 system.net.mail.attachment
to help me create an email attachment in memory.
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
I receive this error :
我收到此错误：
Overload resolution failed because no accessible 'New' can be called without a narrowing conversion:
'Public Sub New(contentStream As System.IO.Stream, contentType As System.Net.Mime.ContentType)': Argument matching parameter 'contentStream' narrows from 'Object' to 'System.IO.Stream'.
'Public Sub New(fileName As String, contentType As System.Net.Mime.ContentType)': Argument matching parameter 'fileName' narrows from 'Object' to 'String'.
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“新”：
'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)
at this line.
在这一行。
How can I fix this?
我怎样才能解决这个问题？
采纳答案by Hyman Gajanan
or use this
或使用这个
Using MemoryStream As MemoryStream = new MemoryStream()
回答by Teppic
In your Using statement you are initialising the variable named MemoryStream as an Object rather than as a MemoryStream.
在您的 Using 语句中，您将名为 MemoryStream 的变量初始化为 Object 而不是 MemoryStream。
Try changing your Using statement from
尝试将您的 Using 语句从
Using MemoryStream = New MemoryStream
to
到
Using MemoryStream As New MemoryStream
