Question

首先，对于这个微不足道的问题我很抱歉，我是新手，还在学习。我正在使用vb.net构建一个连接到FTP服务器列表文件的应用程序，并根据文件扩展名过滤这些文件。然后下载并删除该文件。

我收到错误：＆＃34;底层连接已关闭：服务器违反了协议＃34;

这是我调用方法的地方。

Call GetDirectoryListing(strExtension, strPastaDownload, strUser, strPsswd)
        strFileNumber = Cont_Files
        Dim blnDownloaded As Boolean = False
        If Cont_Files > 0 Then
            For cont = 0 To Cont_Files - 1
                nameFile = arrArq(cont)
                strFilename = UCase(nameFile)
                strLocal = AppPath & strLocalArquivos & "\" & nameFile
                blnDownloaded = mFTP.FtpDownloadFile(strPastaDownload, strNomedoArquivo, strLocal, strUsuario, strSenha)
                StrDir = Dir(strdirectory)
                strRemote = nameFile
                If StrDir <> "" Then
                    FileCopy(AppPath & strfiledirectory & "\" & Trim(strRemote), strLocalBackup & "\" & Trim(strRemote))
                    mFTP.FtpDeleteFile(strServer, strPastaFtp, strFilename, strUsuario, strSenha)
                End If
            Next

这里列出文件的功能我在这里没有任何错误只是为了说明

  Public Function GetDirectoryListing(ByVal sFilter As String, ByVal strServer As String, ByVal strLogin As String, ByVal strPassword As String) As ArrayList

    Dim ftpRequest As FtpWebRequest = Nothing
    Try
        ftpRequest = FtpWebRequest.Create(New Uri(strServer))
        With ftpRequest
            .Credentials = New NetworkCredential(strLogin, strPassword)
            .UsePassive = True
            .Method = WebRequestMethods.Ftp.ListDirectory
            .KeepAlive = True
        End With
        'ftpRequest.Method = WebRequestMethods.Ftp.ListDirectory  'List, not Download
        'Read the contents of the directory and store it into a string array
        Dim srReader As New StreamReader(ftpRequest.GetResponse().GetResponseStream())
        sDirectoryList = srReader.ReadToEnd().Split(vbNewLine)
        For i As Integer = 0 To UBound(sDirectoryList) - 1
            If sFilter = Mid(sDirectoryList(i), Len(sDirectoryList(i)) - 2, 3) Then
                listaArquivo.Add(sDirectoryList(i))
            End If

        Next

        'Clear the last split vbNewLine
        If sDirectoryList IsNot Nothing Then
            sDirectoryList(sDirectoryList.Length - 1) = ""
        End If

        srReader.Close()
        srReader = Nothing
        GetDirectoryListing = listaArquivo
        ftpRequest = Nothing


    Catch ex As WebException
        MessageBox.Show("Failed to get directory listing. GetDirectoryListing()")
        'MessageBox.Show(ex.ToString())
    End Try

End Function

以下是下载功能

Public Function FtpDownloadFile(ByVal strUrl As String, ByVal strFileName As String, ByVal strTargetDirectory As String, ByVal strLogin As String, ByVal strPassword As String) As Boolean

        Dim ftpRequest As FtpWebRequest = Nothing
        Dim ftpResponse As FtpWebResponse = Nothing
        Dim strFtpFile As String = ""
        Dim strTargetFile As String = ""
        Dim strmReader As StreamReader = Nothing
        Dim strmResponse As Stream = Nothing
        Dim strmTarget As Stream = Nothing
        Dim strmWriter As StreamWriter = Nothing

        strFtpFile = strUrl & "/" & Trim(strFileName)
        strTargetFile = strTargetDirectory

        Try
            ftpRequest = CType(WebRequest.Create(strFtpFile), FtpWebRequest)

            With ftpRequest
                .Credentials = New NetworkCredential(strLogin, strPassword)
                .UsePassive = True
                .Method = WebRequestMethods.Ftp.DownloadFile
                .KeepAlive = True
            End With

            ftpResponse = CType(ftpRequest.GetResponse(), FtpWebResponse) 'line where I am getting the error

            strmTarget = New FileStream(strTargetFile, FileMode.Create)
            strmWriter = New StreamWriter(strmTarget)
            strmResponse = ftpResponse.GetResponseStream()
            strmReader = New StreamReader(strmResponse, System.Text.Encoding.UTF8)
            strmWriter.Write(strmReader.ReadToEnd())

        Catch ex As Exception
            Throw ex

        Finally
        If strmReader IsNot Nothing Then
            strmReader.Close()
            strmReader.Dispose()
        End If

        If strmWriter IsNot Nothing Then
            strmWriter.Close()
            strmWriter.Dispose()
        End If

        If ftpResponse IsNot Nothing Then
            ftpResponse.Close()
            ftpResponse = Nothing
        End If


        If ftpRequest IsNot Nothing Then ftpRequest = Nothing
    End Try


    Return True

End Function

提前感谢您的帮助

Answer 1

我认为问题出在FtpDownloadFile方法的第WebRequest行中，将FtpWebRequest转换为ftpRequest = FtpWebRequest.Create(New Uri(strServer)) ftpRequest = CType(WebRequest.Create(strFtpFile), FtpWebRequest)。它们不一样。

{{1}}

尝试确保每次都以相同的方式连接到服务器。使用有效的方式。

底层连接已关闭：服务器提交了协议违规

1 个答案: