vb.net - 使用VB.net通过拖放将多个文件上传到FTP服务器时出现问题

Question

我试图通过拖放将多个文件添加到FTP服务器，并且能够使用try catch块来做到这一点，如果我们正确设置ftp设置，则需要1秒钟的时间来上传它们，但是当我们输入错误的详细信息时，它就会挂起，如果我给出特殊消息，也不会给我任何错误消息。

现在我收到添加的每个文件的错误消息以及成功消息，我不希望发生这种情况。

谁能说出成功和失败的信息，上传应该花几秒钟，如果没有，我应该立即给我信息。

我完全弄错了我要去哪里。

任何帮助将不胜感激!

这是我的代码:

Private Sub uploadFile(ByVal FTPAddress As String, ByVal filePath As String, ByVal username As String, ByVal password As String) 'Create FTP request

    Try
        Dim request As FtpWebRequest = DirectCast(FtpWebRequest.Create(FTPAddress & "/" & Path.GetFileName(filePath)), FtpWebRequest)

        request.Method = WebRequestMethods.Ftp.UploadFile
        request.Credentials = New NetworkCredential(username, password)
        request.UsePassive = True
        request.UseBinary = True
        request.KeepAlive = False

        Dim buffer As Byte() = Nothing
        'Load the file
        Using stream As FileStream = File.OpenRead(filePath)
            buffer = New Byte(CInt(stream.Length - 1)) {}
            stream.Read(buffer, 0, buffer.Length)
        End Using

        'Upload file
        Using reqStream As Stream = request.GetRequestStream()
            reqStream.Write(buffer, 0, buffer.Length)
        End Using

        MsgBox("Uploaded Successfully", MsgBoxStyle.Information)
    Catch
       MsgBox("Failed to upload.Please check the ftp settings", MsgBoxStyle.Critical)
    End Try
End Sub

这是拖放的代码

 Private Sub FlowLayoutPanel1_DragDrop(ByVal sender As Object, ByVal e As System.Windows.Forms.DragEventArgs) Handles FlowLayoutPanel1.DragDrop
    Try

        Dim Files As String() = CType(e.Data.GetData(DataFormats.FileDrop), String())

        For Each FileName As String In Files
                           Dim Extension As String = Path.GetExtension(FileName).ToLower
            If Array.IndexOf(SupportedExtensions, Extension) <> -1 Then
                uploadFile(txtFTPAddress.Text, FileName, txtUsername.Text, txtPassword.Text)

            End If

        Next
    Catch

    End Try

End Sub

Answer 1

由于每次加载文件时都会调用uploadFile，因此您可能需要将错误处理代码从该方法移至dragDrop方法。这样，您将仅收到一条消息，说明整个操作成功或失败。您还可以将FtpWebRequest上的Timeout属性设置为取消上传，如果它花费的时间超过几秒钟。

然后uploadFile变为:

Private Sub uploadFile(ByVal FTPAddress As String, ByVal filePath As String, ByVal username As String, ByVal password As String) 'Create FTP request
    Dim request as FtpWebRequest = ...
    request.Timeout = 5000 ' Set timeout to 5 seconds
    '... several lines omitted
    'Upload file
    Using reqStream As Stream = request.GetRequestStream()
        reqStream.Write(buffer, 0, buffer.Length)
    End Using
End Sub

然后，您可以将错误处理代码移到处理拖放的方法中:

Private Sub FlowLayoutPanel1_DragDrop(ByVal sender As Object, ByVal e As  
    System.Windows.Forms.DragEventArgs) Handles FlowLayoutPanel1.DragDrop
    Try
       ' ... several lines omitted
       Next
       MsgBox("Uploaded Successfully", MsgBoxStyle.Information)
    Catch
       MsgBox("Failed to upload.Please check the ftp settings", MsgBoxStyle.Critical)
    End Try
End Sub