如何从FTP下载文件并再次上传

Question

我需要从FTP服务器下载文件并对其进行一些更改，然后使用VB.NET将其再次上传到同一FTP。

请帮忙。 谢谢。

Answer 1

一些链接：

VB.NET： http://www.codeproject.com/KB/IP/FtpClient.aspx

C＃： http ： //www.c-sharpcorner.com/uploadfile/neo_matrix/simpleftp01172007082222am/simpleftp.aspx

Answer 2

如果您只想直接重新上传文件，只需将下载流通过管道传输到上传流：

Dim downloadRequest As FtpWebRequest =
    WebRequest.Create("ftp://downloadftp.example.com/source/path/file.txt")
downloadRequest.Method = WebRequestMethods.Ftp.DownloadFile
downloadRequest.Credentials = New NetworkCredential("username1", "password1")

Dim uploadRequest As FtpWebRequest =
    WebRequest.Create("ftp://uploadftp.example.com/target/path/file.txt")
uploadRequest.Method = WebRequestMethods.Ftp.UploadFile
uploadRequest.Credentials = New NetworkCredential("username2", "password2")

Using downloadResponse As FtpWebResponse = downloadRequest.GetResponse(),
      sourceStream As Stream = downloadResponse.GetResponseStream(),
      targetStream As Stream = uploadRequest.GetRequestStream()
    sourceStream.CopyTo(targetStream)
End Using

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如果您需要以某种方式处理内容，或者需要监视进度，或者两者兼而有之，则必须逐块（或者如果要处理的是文本文件，则逐行处理）：

Dim downloadRequest As FtpWebRequest =
    WebRequest.Create("ftp://downloadftp.example.com/source/path/file.txt")
downloadRequest.Method = WebRequestMethods.Ftp.DownloadFile
downloadRequest.Credentials = New NetworkCredential("username1", "password1")

Dim uploadRequest As FtpWebRequest =
    WebRequest.Create("ftp://uploadftp.example.com/target/path/file.txt")
uploadRequest.Method = WebRequestMethods.Ftp.UploadFile
uploadRequest.Credentials = New NetworkCredential("username2", "password2")

Using downloadResponse As FtpWebResponse = downloadRequest.GetResponse(),
      sourceStream As Stream = downloadResponse.GetResponseStream(),
      targetStream As Stream = uploadRequest.GetRequestStream()
    Dim buffer As Byte() = New Byte(10240 - 1) {}
    Dim read As Integer
    Do
        read = sourceStream.Read(buffer, 0, buffer.Length)
        If read > 0 Then
            ' process "buffer" here
            targetStream.Write(buffer, 0, read)
        End If
    Loop While read > 0
End Using

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也可以看看：

• 使用VB.NET将文件上传到FTP站点
• 从VB.NET的FTP文件夹下载所有文件和子目录