FTP上传损坏文件

Question

我正在处理的程序在上传 Excel 文件时会损坏它们。 该文件在本地计算机上正常，但在远程计算机上，该文件在 Excel 中打开时显示已损坏。 Excel 可以修复文件，但我不想避免这个问题。
到目前为止，我似乎对图像文件没有任何问题。

Public Function UploadFile(ByVal User As String, ByVal oFile As FileInfo) As Boolean
    Dim ftpRequest As FtpWebRequest
    Dim ftpResponse As FtpWebResponse
    Try
        FtpCheckAndCreateDir(User)

        ftpRequest = CType(FtpWebRequest.Create(Base + User + "/" + oFile.Name), FtpWebRequest)
        ftpRequest.Method = WebRequestMethods.Ftp.UploadFile
        ftpRequest.Proxy = Nothing
        ftpRequest.UseBinary = True
        ftpRequest.Credentials = Cred ' New NetworkCredential(...)
        ftpRequest.KeepAlive = KeepAlive ' false
        ftpRequest.EnableSsl = UseSSL ' false
        If UseSSL Then ServicePointManager.ServerCertificateValidationCallback = New RemoteCertificateValidationCallback(AddressOf ValidateServerCertificate)
        Dim fileContents(oFile.Length) As Byte
        Using fr As FileStream = oFile.OpenRead
            fr.Read(fileContents, 0, Convert.ToInt32(oFile.Length))
        End Using
        Using writer As Stream = ftpRequest.GetRequestStream
            writer.Write(fileContents, 0, fileContents.Length)
        End Using
        ftpResponse = CType(ftpRequest.GetResponse, FtpWebResponse)
        ftpResponse.Close()
        ftpRequest = Nothing
        Return True
    Catch ex As WebException
        Return False
    End Try
End Function

编辑：
于是我拿了一个文件，通过coffeecup free ftp上传，下载了，打开就好了。
我用我的程序上传文件，然后用coffeecup下载它，当我试图在excel中打开它时它出现了损坏。
我使用 HxD 比较文件，它返回一条消息说：“选择的文件是相同的。但是文件大小不同！”当我对两个文件运行校验和时，它们会返回不同的值。

我不确定如何解决此问题或我可以研究什么来找到答案。
如果需要，我可以提供文件。

Answer 1

所以，经过大量搜索和寻找，我找到了这个答案：C# - File is corrupt after uploaded to server

我可以使用它来获取要上传的文件而不会损坏。

注释掉旧部分的最终 ftp 函数以便更容易看到更改：

Public Function UploadFile(ByVal User As String, ByVal oFile As FileInfo) As Boolean
    Dim ftpRequest As FtpWebRequest
    Dim ftpResponse As FtpWebResponse
    Try
        FtpCheckAndCreateDir(User)

        ftpRequest = CType(FtpWebRequest.Create(Base + User + "/" + oFile.Name), FtpWebRequest)
        ftpRequest.Method = WebRequestMethods.Ftp.UploadFile
        ftpRequest.Proxy = Nothing
        ftpRequest.UseBinary = True
        ftpRequest.Credentials = Cred
        ftpRequest.KeepAlive = KeepAlive
        ftpRequest.EnableSsl = UseSSL
        If UseSSL Then ServicePointManager.ServerCertificateValidationCallback = New RemoteCertificateValidationCallback(AddressOf ValidateServerCertificate)
        Dim fileContents(oFile.Length) As Byte

        Using fr As FileStream = oFile.OpenRead
            Using writer As Stream = ftpRequest.GetRequestStream
                fr.CopyTo(writer) ' This is the important part.
                'writer.Write(fileContents, 0, fileContents.Length)
            End Using
            'fr.Read(fileContents, 0, Convert.ToInt32(oFile.Length))
        End Using
        'Using writer As Stream = ftpRequest.GetRequestStream
        '    writer.Write(fileContents, 0, fileContents.Length)
        'End Using
        ftpResponse = CType(ftpRequest.GetResponse, FtpWebResponse)
        ftpResponse.Close()
        ftpRequest = Nothing
        Return True
    Catch ex As WebException
        Return False
    End Try
End Function

Answer 2

问题在于您的文件编写器，重要的是要注意图像在缺少信息时非常宽容。

我希望这个 FTP 课程能帮助你走上正确的道路：

Public Class FTP
    '-------------------------[BroCode]--------------------------
    '----------------------------FTP-----------------------------
    Private _credentials As System.Net.NetworkCredential
    Sub New(ByVal _FTPUser As String, ByVal _FTPPass As String)
        setCredentials(_FTPUser, _FTPPass)
    End Sub
    Public Sub UploadFile(ByVal _FileName As String, ByVal _UploadPath As String)
        Dim _FileInfo As New System.IO.FileInfo(_FileName)
        Dim _FtpWebRequest As System.Net.FtpWebRequest = CType(System.Net.FtpWebRequest.Create(New Uri(_UploadPath)), System.Net.FtpWebRequest)
        _FtpWebRequest.Credentials = _credentials
        _FtpWebRequest.KeepAlive = False
        _FtpWebRequest.Timeout = 20000
        _FtpWebRequest.Method = System.Net.WebRequestMethods.Ftp.UploadFile
        _FtpWebRequest.UseBinary = True
        _FtpWebRequest.ContentLength = _FileInfo.Length
        Dim buffLength As Integer = 2048
        Dim buff(buffLength - 1) As Byte
        Dim _FileStream As System.IO.FileStream = _FileInfo.OpenRead()
        Try
            Dim _Stream As System.IO.Stream = _FtpWebRequest.GetRequestStream()
            Dim contentLen As Integer = _FileStream.Read(buff, 0, buffLength)
            Do While contentLen <> 0
                _Stream.Write(buff, 0, contentLen)
                contentLen = _FileStream.Read(buff, 0, buffLength)
            Loop
            _Stream.Close()
            _Stream.Dispose()
            _FileStream.Close()
            _FileStream.Dispose()
        Catch ex As Exception
            MessageBox.Show(ex.Message, "Upload Error: ", MessageBoxButtons.OK, MessageBoxIcon.Error)
        End Try
    End Sub
    Public Sub DownloadFile(ByVal _FileName As String, ByVal _ftpDownloadPath As String)
        Try
            Dim _request As System.Net.FtpWebRequest = System.Net.WebRequest.Create(_ftpDownloadPath)
            _request.KeepAlive = False
            _request.Method = System.Net.WebRequestMethods.Ftp.DownloadFile
            _request.Credentials = _credentials
            Dim _response As System.Net.FtpWebResponse = _request.GetResponse()
            Dim responseStream As System.IO.Stream = _response.GetResponseStream()
            Dim fs As New System.IO.FileStream(_FileName, System.IO.FileMode.Create)
            responseStream.CopyTo(fs)
            responseStream.Close()
            _response.Close()
        Catch ex As Exception
            MessageBox.Show(ex.Message, "Download Error: ", MessageBoxButtons.OK, MessageBoxIcon.Error)
        End Try
    End Sub
    Public Function GetDirectory(ByVal _ftpPath As String) As List(Of String)
        Dim ret As New List(Of String)
        Try
            Dim _request As System.Net.FtpWebRequest = System.Net.WebRequest.Create(_ftpPath)
            _request.KeepAlive = False
            _request.Method = System.Net.WebRequestMethods.Ftp.ListDirectoryDetails
            _request.Credentials = _credentials
            Dim _response As System.Net.FtpWebResponse = _request.GetResponse()
            Dim responseStream As System.IO.Stream = _response.GetResponseStream()
            Dim _reader As System.IO.StreamReader = New System.IO.StreamReader(responseStream)
            Dim FileData As String = _reader.ReadToEnd
            Dim Lines() As String = FileData.Split(New String() {Environment.NewLine}, StringSplitOptions.RemoveEmptyEntries)
            For Each l As String In Lines
                ret.Add(l)
            Next
            _reader.Close()
            _response.Close()
        Catch ex As Exception
            MessageBox.Show(ex.Message, "Directory Fetch Error: ", MessageBoxButtons.OK, MessageBoxIcon.Error)
        End Try
        Return ret
    End Function

    Private Sub setCredentials(ByVal _FTPUser As String, ByVal _FTPPass As String)
        _credentials = New System.Net.NetworkCredential(_FTPUser, _FTPPass)
    End Sub
End Class