Question

我不是VB的经验丰富的程序员。

我正在创建一个桌面应用程序，用户可以通过ftp将某些文件上传到服务器。

这些文件都在本地的同一文件夹中，并上传到服务器上的同一文件夹。

我正在使用这段代码：

For Each File As String In My.Computer.FileSystem.GetFiles( _
                                    path, _
                                    FileIO.SearchOption.SearchAllSubDirectories, _
                                    "*.jpg")
    Dim fileInf As IO.FileInfo = New IO.FileInfo(File)
    Dim uri As String = serveruri
    Dim reqFTP As Net.FtpWebRequest
    reqFTP = Net.FtpWebRequest.Create(New Uri(uri))   
    reqFTP.Credentials = New Net.NetworkCredential(user, pass)
    reqFTP.KeepAlive = False
    reqFTP.Method = Net.WebRequestMethods.Ftp.UploadFile    
    reqFTP.UseBinary = True
    reqFTP.ContentLength = fileInf.Length
    Dim buffLength As Integer = 2048
    Dim buff(buffLength) As Byte
    Dim contentLen As Integer  
    Dim fs As IO.FileStream = fileInf.OpenRead()
    Dim strm As IO.Stream = reqFTP.GetRequestStream()
    contentLen = fs.Read(buff, 0, buffLength)
    While Not (contentLen = 0) 
        strm.Write(buff, 0, contentLen)
        contentLen = fs.Read(buff, 0, buffLength)
    End While 
    strm.Close()
    fs.Close()        
Next

使用此代码，我逐个上传文件，但总花费时间过长。

如何减少总花费时间？

我曾想过用线程做这件事或者异步上传文件但我找不到任何如何做的例子。

谢谢！

Answer 1

我们使用此代码异步执行类似的工作：

  w = New System.Net.WebClient

        w.Credentials = New Net.NetworkCredential(username, Password)

        w.UploadFileAsync(New System.Uri("ftp://ftp.yourdomain/yourfilename"), bupath)

Answer 2

用户我的FTP课程

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

ftp在VB.NET中上传多个文件的最佳方法是什么？

2 个答案: