直接上传新 Ftp 列表框行

Question

我可以（上传/添加）列表框行到当前 Ftp 列表框行服务器没有下载以前的 ftp 服务器列表框值。

而不是将添加的列表框行上传到 Ftp 列表框行服务器！

我可以简单地发送列表框新行，然后将其添加到当前列表框 ftp 服务器行（不删除旧行，只添加新行）当前 Ftp 行列表框无需下载和上传整个 ftp 列表框？

示例：这是我的代码

Download Code (Button 1) [not important]

   Dim request As FtpWebRequest =
   WebRequest.Create("ftp://test.com/test.txt")
   request.Method = WebRequestMethods.Ftp.DownloadFile
   request.Credentials = New NetworkCredential("tester1", 
           "password")

        Using response As FtpWebResponse = request.GetResponse(),
                  stream As Stream = response.GetResponseStream(),
                  reader As StreamReader = New StreamReader(stream)
            While Not reader.EndOfStream
                listbox1.Items.Add(reader.ReadLine())
            End While
        End Using

          ' Adding the listbox item's Before upload it again'

        listbox1.Items.Add(".")

Upload Code (Button 2)

[important to make it direct upload new lines to currently ftp listbox lines server]

                Dim request As FtpWebRequest =
                WebRequest.Create("ftp://test.com/test.txt")
                request.Method = WebRequestMethods.Ftp.UploadFile
                request.Credentials = New NetworkCredential("tester1", 
               "password")
                request.UseBinary = False

                Using stream As Stream = request.GetRequestStream(),
                          writer As StreamWriter = New StreamWriter(stream)
                    For index As Integer = 0 To listbox1.Items.Count - 1

                        writer.WriteLine(listbox1.Items(index))
                    Next
                End Using

            Catch ex As Exception

此致

Answer 1

注意：我看到您使用的是 Visual Studio 2012。可能不支持某些代码（未指定 .Net 版本）。如果是这种情况，请对此发表评论。

WebRequest支持FTP APPE command for its FtpWebRequest化身。

参见WebRequestMethods.Ftp → WebRequestMethods.Ftp.AppendFile。

此方法发送 Ftp APPE 命令。如果上传的文件存在，则会追加新的内容。
在编写文本文件时，您可能希望在每一行后附加一个 Environment.Newline 序列，if/when 需要。

因为您有一个 ListBox 控件，您可以提取它的 Items 文本并以这种方式为每个项目字符串值添加一个换行符：

Dim TextLines As String() = listBox1.Items.Cast(Of String)().Select(Function(ln) Environment.NewLine + ln).ToArray()

你可以这样调用后面的方法：

Dim result As Long = Await FtpAppenAsync("ftp://ftp.server.com/[EntryDir]/[ExistingFile]", TextLines)

这是一个修改后的方法，允许将一些文本行附加到 FTP 服务器上的现有文本文件：
（注意 StreamWriter 的 Encoding：它设置为 Default → 当前本地代码页。
如果未指定编码，则默认为 UTF8。根据需要修改).

Public Async Function FtpAppenAsync(ResourceName As String, TextData As String()) As Task(Of Integer)

    Dim request As FtpWebRequest = CType(WebRequest.Create(ResourceName), FtpWebRequest)
    request.Credentials = New NetworkCredential("[FtpAccount]", "[FtpPassword]")
    request.Method = WebRequestMethods.Ftp.AppendFile
    request.UseBinary = True
    request.UsePassive = True

    Dim TextLinesWritten As Integer = 0
    Try
        Using ftpStream As Stream = Await request.GetRequestStreamAsync()
            Using ftpWriter As New StreamWriter(ftpStream, Encoding.Default)
                For Each TextLine As String In TextData
                    Await ftpWriter.WriteAsync(TextLine)
                    TextLinesWritten += 1
                    Console.WriteLine("Uploaded {0} lines", TextLinesWritten)
                Next
            End Using
        End Using
        Using response As FtpWebResponse = CType(Await request.GetResponseAsync(), FtpWebResponse)
            'Log-Return the StatusCode of the failed upload
            If Not (response.StatusCode = FtpStatusCode.ClosingData) Then Return -1
        End Using
    Catch ex As Exception
        'Log/report ex
        TextLinesWritten = -1
        Throw
    End Try
    Return TextLinesWritten
End Function

如果需要 Ssl 连接，请添加 Imports 和这些行：将它们粘贴到该方法的顶部：
（SecurityProtocolType取决于您的连接要求）

Imports System.Net.Security
Imports System.Security.Cryptography.X509Certificates

'Method code
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12

ServicePointManager.ServerCertificateValidationCallback =
    New RemoteCertificateValidationCallback(Function(s, Cert, Chain, sslErrors)
                                                Return True
                                            End Function)
request.EnableSsl = True

直接上传新 Ftp 列表框行

Direct Uploading New Ftp listbox Lines

.net

vb.net

visual-studio-2012

ftp

listbox