从VB.net上传和下载文件到大型机

Question

如何使用VB.net从大型机数据集上传和下载文件

我拥有大型机数据集的所有FTP详细信息。

Answer 1

在我工作的地方，我们发现您可以在System.Net命名空间中使用FtpWebRequest类。它的使用非常简单。

Answer 2

您应该可以使用WebRequest - 请参阅this post。

Answer 3

以下是从大型机上传和下载的示例

      #Form1.vb
      #====



Public Class Form1
    Dim myftp As New ftpClient()


    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim strReturnFields As String = ""
        Dim strName As String
        Dim strPWD As String
        Dim strftpLogin As String

        'FieldsChek(strReturnFields)

        If strReturnFields.Length > 0 Then
            MessageBox.Show(strReturnFields + " cannot be empty")
            Return
        End If

        strName = userName.Text
        strPWD = Password.Text
        strftpLogin = Server.Text

        myftp.LogInFTP(strName, strPWD, strftpLogin)
        txtMessage.Text = myftp.GetReturnNameMessage
        txtMessage.Text = txtMessage.Text + myftp.GetReturnPwdMessage
    End Sub

    Private Sub btnFTPUpload_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnFTPUpload.Click
        Dim strUPFilePath As String
        Dim strFtpAddress As String
        Dim strMessage As String

        strUPFilePath = txtFilePath.Text
        strFtpAddress = txtDestFile.Text
        myftp.FTPUpLoad(strUPFilePath, strFtpAddress, strMessage)
        txtMessage.Text += vbCrLf + strMessage
    End Sub


    Private Sub btnDelete_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDelete.Click
        Dim strFile As String = txtDestFile.Text
        Dim strReturnMessage As String
        strReturnMessage = myftp.DeleteFile(strFile)
        txtMessage.Text += vbCrLf + strReturnMessage
    End Sub


    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Dim strReturnMessage As String
        strReturnMessage = myftp.QuitFTP(strReturnMessage)
        txtMessage.Text += vbCrLf + strReturnMessage
    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    End Sub
End Class


      #===============
      #ftpCreate.vb
      #=============


    Imports System.Net.Sockets
    Imports System.Text
    Imports System.Threading

Public Class ftpCreate
    Private ftpTcpClient As TcpClient
    Public ResponseStream As NetworkStream
    Public ReturnNameMessage As String
    Public ReturnPwdMessage As String

    Public Sub ftpLogin(ByVal strName As String, ByVal strPWD As String, ByVal strftpLogin As String)
        Try
            Dim strCommand As String
            Dim strReturnMessage As String
            Dim bteSendBytes() As Byte
            'Dim bteSendBytes As [Byte]()
            Dim bteRetruenBytes() As Byte
            Dim intReturnByteLength As Integer
            Dim ftpTcpClient As TcpClient = New TcpClient(strftpLogin, 21)
            ResponseStream = ftpTcpClient.GetStream

            strCommand = "USER " + strName + vbCrLf

            bteSendBytes = System.Text.Encoding.ASCII.GetBytes(strCommand)

            ResponseStream.Write(bteSendBytes, 0, bteSendBytes.Length)
            intReturnByteLength = ftpTcpClient.ReceiveBufferSize

            ReDim bteRetruenBytes(intReturnByteLength)

            ResponseStream.Read(bteRetruenBytes, 0, intReturnByteLength)
            strReturnMessage = Encoding.ASCII.GetString(bteRetruenBytes) + "/ "
            ReturnNameMessage = strCommand + strReturnMessage

            Thread.Sleep(1000)
            strCommand = "PASS " + strPWD + vbCrLf

            Array.Clear(bteSendBytes, 0, bteSendBytes.Length)
            bteSendBytes = Encoding.ASCII.GetBytes(strCommand)
            ResponseStream.Write(bteSendBytes, 0, bteSendBytes.Length)
            intReturnByteLength = ftpTcpClient.ReceiveBufferSize

            Thread.Sleep(1000)
            ReDim bteRetruenBytes(intReturnByteLength)

            ResponseStream.Read(bteRetruenBytes, 0, intReturnByteLength)
            strReturnMessage = Encoding.ASCII.GetString(bteRetruenBytes) + "/ "
            ReturnPwdMessage = strCommand + strReturnMessage + vbCrLf

            strCommand = "TYPE " + "E" + vbCrLf

            Array.Clear(bteSendBytes, 0, bteSendBytes.Length)
            bteSendBytes = Encoding.ASCII.GetBytes(strCommand)
            ResponseStream.Write(bteSendBytes, 0, bteSendBytes.Length)
            intReturnByteLength = ftpTcpClient.ReceiveBufferSize

            Thread.Sleep(1000)
            ReDim bteRetruenBytes(intReturnByteLength)

            ResponseStream.Read(bteRetruenBytes, 0, intReturnByteLength)
            strReturnMessage = Encoding.ASCII.GetString(bteRetruenBytes) + "/ "
            ReturnPwdMessage = strCommand + strReturnMessage + vbCrLf

        Catch ex As SocketException
            ReturnPwdMessage = ex.Message
        End Try
    End Sub

End Class

 #====
 #ftpClient.vb
 #====

Imports System.Net
Imports System.IO
Imports System.Net.Sockets
Imports System.Text


Public Class ftpClient

    Dim ReturnNameMessage
    Dim ReturnPwdMessage
    Dim myftpCreate As ftpCreate

    Public Sub LogInFTP(ByVal strName As String, ByVal strPWD As String, ByVal strftpLogin As String)
        myftpCreate = New ftpCreate()
        myftpCreate.ftpLogin(strName, strPWD, strftpLogin)
        ReturnNameMessage = myftpCreate.ReturnNameMessage
        ReturnPwdMessage = myftpCreate.ReturnPwdMessage
    End Sub

    Public ReadOnly Property GetReturnNameMessage() As String
        Get
            Return ReturnNameMessage
        End Get
    End Property
    Public ReadOnly Property GetReturnPwdMessage() As String
        Get
            Return ReturnPwdMessage
        End Get
    End Property
    Public Sub FTPUpLoad(ByVal strFilePath As String, ByVal strFtpPath As String, ByRef pstrReturnMessage As String)

        Dim UPFile As New FileStream(strFilePath, FileMode.Open)
        Dim bytUPFile() As Byte
        Dim outstream As String
        Dim lngFileLength As Long
        Dim ftpStream As NetworkStream = myftpCreate.ResponseStream
        Dim returnMessage As String
        Dim UpLoadStream As NetworkStream

        Dim BLOCK_SIZE As Integer = 512
        Dim buffer As Byte() = New Byte(BLOCK_SIZE - 1) {}
        Dim ASCII As Encoding = Encoding.ASCII

        Try
            lngFileLength = UPFile.Length
            ReDim bytUPFile(lngFileLength)
            UPFile.Read(bytUPFile, 0, lngFileLength)

            outstream = Encoding.ASCII.GetString(bytUPFile)
            bytUPFile = Encoding.ASCII.GetBytes(outstream)


            FTPCommands(ftpStream, "PASV", returnMessage)
            UpLoadStream = GetConnectTcpClient(returnMessage)

            FTPCommands(ftpStream, "TYPE A", returnMessage)
            FTPCommands(ftpStream, "STOR " + strFtpPath, returnMessage)
            pstrReturnMessage += returnMessage.TrimEnd
            'UpLoadStream.Write(outstream, 0, lngFileLength)

            UpLoadStream.Write(bytUPFile, 0, lngFileLength)
            UpLoadStream.Close()
            UPFile.Close()

        Catch ex As Exception
            pstrReturnMessage = ex.Message
        End Try
    End Sub
    Public Sub FTPDownLoad(ByVal strFilePath As String, ByVal strFtpPath As String, ByRef pstrReturnMessage As String)

        Dim UPFile As New FileStream(strFtpPath, FileMode.Create)
        Dim bytUPFile() As Byte
        Dim lngFileLength As Long
        Dim ftpStream As NetworkStream = myftpCreate.ResponseStream
        Dim returnMessage As String

        FTPCommands(ftpStream, "PASV", returnMessage)
        Dim DownloadStream As NetworkStream
        DownloadStream = GetConnectTcpClient(returnMessage)
        FTPCommands(ftpStream, "TYPE I", returnMessage)
        FTPCommands(ftpStream, "RETR " + strFilePath, returnMessage)
        pstrReturnMessage += returnMessage

        ReDim bytUPFile(1024)
        Do
            lngFileLength = DownloadStream.Read(bytUPFile, 0, 1024)
            UPFile.Write(bytUPFile, 0, lngFileLength)
        Loop While lngFileLength > 0

        UPFile.Close()
        DownloadStream.Close()
    End Sub
    Private Function FTPCommands(ByVal ftpStream As NetworkStream, ByVal strCommand As String, ByRef strMessage As String) As Integer
        Dim bteCommand() As Byte
        bteCommand = Encoding.ASCII.GetBytes(strCommand + vbCrLf)
        ftpStream.Write(bteCommand, 0, bteCommand.Length)
        Dim b(360000) As Byte
        ftpStream.Read(b, 0, 360000)
        strMessage = Encoding.ASCII.GetString(b)
    End Function
    Private Function GetConnectTcpClient(ByVal respMessage As String) As NetworkStream

        Dim i As Integer
        Dim strIP As String
        Dim strIPs() As String
        Dim strAddress As String
        Dim intPort As Integer
        Try
            strIP = respMessage.Substring(respMessage.IndexOf("(")).Replace("(", "")
            strIPs = strIP.Split(",")
            strIP = ""
            For i = 0 To 3
                strIP += strIPs(i) + "."
            Next
            strAddress = strIP.Substring(0, strIP.Length - 1)
            intPort = Integer.Parse(strIPs(4)) * 256 + _
                      Integer.Parse(strIPs(5).Substring(0, strIPs(5).IndexOf(")")))
            Dim dataClient As New TcpClient()
            Dim cIPEP As New IPEndPoint(IPAddress.Parse(strAddress), intPort)
            dataClient.Connect(cIPEP)
            Return dataClient.GetStream
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
    End Function
    Public Function CreateDir(ByVal strDirPath As String) As String

        Dim ftpStream As NetworkStream = myftpCreate.ResponseStream
        Dim returnMessage As String
        FTPCommands(ftpStream, "MKD " + strDirPath, returnMessage)
        returnMessage = "Creating Dir" + vbCrLf + returnMessage
        Return returnMessage
        ftpStream.Close()

    End Function
    Public Function DeleteDir(ByVal strDirPath As String) As String

        Dim ftpStream As NetworkStream = myftpCreate.ResponseStream
        Dim returnMessage As String
        FTPCommands(ftpStream, "RMD " + strDirPath, returnMessage)
        returnMessage = "Delete Dir" + vbCrLf + returnMessage
        Return returnMessage
        ftpStream.Close()

    End Function
    Public Function PrintDir() As String

        Dim ftpStream As NetworkStream = myftpCreate.ResponseStream
        Dim returnMessage As String
        FTPCommands(ftpStream, "PWD ", returnMessage)
        returnMessage = returnMessage
        Return returnMessage
        ftpStream.Close()

    End Function
    Public Function ChangeDir(ByVal strDirPath As String) As String

        Dim ftpStream As NetworkStream = myftpCreate.ResponseStream
        Dim returnMessage As String
        FTPCommands(ftpStream, "CWD " + strDirPath, returnMessage)
        returnMessage = returnMessage
        Return returnMessage
        ftpStream.Close()

    End Function
    Public Function DeleteFile(ByVal strFile As String) As String
        Dim ftpStream As NetworkStream = myftpCreate.ResponseStream
        Dim returnMessage As String
        FTPCommands(ftpStream, "DELE " + strFile, returnMessage)
        returnMessage = returnMessage
        Return returnMessage
        ftpStream.Close()
    End Function
    Public Function QuitFTP(ByVal strFile As String) As String
        Dim ftpStream As NetworkStream = myftpCreate.ResponseStream
        Dim returnMessage As String
        FTPCommands(ftpStream, "QUIT", returnMessage)
        returnMessage = returnMessage
        Return returnMessage
        ftpStream.Close()
    End Function

End Class