VB.Net Webclient 上传挂起

Question

我有多个文件要使用此代码上传（到 FTP 服务器）：

    Private Sub UploadFile(ByVal local As String)
    If wc.IsBusy = True Then Throw New Exception("An upload is already ongoing!")

    wc.Credentials = New NetworkCredential(usr.ToString, pass.ToString) 'Set the credentials.
    'total_dl_size = GetDownloadSize(url) 'Get the size of the current file.

    Try
        Dim FileName As String = Path.GetFileName(local) 'Get the current file's name.
        AppendWarning("Uploading " & FileName & "...   ") 'Download notice.
        wc.UploadFileAsync(New Uri(info_srv & local), Path.Combine(mc_dir, local)) 'Download the file to the desktop (use your own path here).
    Catch ex As Exception
        AppendWarning("-ERR: Could not download file: " & local & ControlChars.NewLine)
    End Try
End Sub
Private Sub AppendWarning(ByVal Text As String)
    If tb_warnings.InvokeRequired Then
        tb_warnings.Invoke(Sub() tb_warnings.AppendText(Text))
    Else
        tb_warnings.AppendText(Text)
    End If

End Sub

Private Sub wc_UploadProgressChanged(sender As Object, e As System.Net.UploadProgressChangedEventArgs) Handles wc.UploadProgressChanged
    total_ul = e.BytesSent
    Dim Progress As Integer = CType(Math.Round((baseline + total_ul) * 100) / total_ul_size, Integer)
    If ProgressBar1.InvokeRequired Then
        ProgressBar1.Invoke(Sub()

                                If Progress > 100 Then Progress = 100
                                If Progress < 0 Then Progress = 0
                                ProgressBar1.Value = Progress
                            End Sub)
    Else
        If Progress > 100 Then Progress = 100
        If Progress < 0 Then Progress = 0
        ProgressBar1.Value = Progress
    End If
    If lbl_progress.InvokeRequired Then
        lbl_progress.Invoke(Sub() lbl_progress.Text = ((total_ul + baseline) / 1024).ToString("N0") & " KB / " & (total_ul_size / 1024).ToString("N0") & " KB")
    Else
        lbl_progress.Text = ((total_ul + baseline) / 1024).ToString("N0") & " KB / " & (total_ul_size / 1024).ToString("N0") & " KB | " & Progress.ToString & "%"
    End If

End Sub
Private Sub wc_uploadFileCompleted(sender As Object, e As System.ComponentModel.AsyncCompletedEventArgs) Handles wc.UploadDataCompleted
    If e.Cancelled Then
        MessageBox.Show(e.Cancelled)

    ElseIf Not e.Error Is Nothing Then
        MessageBox.Show(e.Error.Message)

    Else
        If files.Count > 0 Then
            AppendWarning("Upload Complete!" & ControlChars.NewLine)
            baseline = baseline + total_ul
            Dim file As String = files.Dequeue()
            MsgBox(file)
            UploadFile(file) 'Download the next file.
        Else
            AppendWarning("All Uploads Finished!" & ControlChars.NewLine)
        End If

    End If

但是，使用我的两个测试文件，它总是停在我给它的第一个文件的末尾，而不会继续到第二个文件。

但是，我有一个 FTP 客户端连接到同一台服务器，当我刷新时，我可以看到（至少对于第一个文件）数据正在正确上传。

关于这里出了什么问题有什么建议吗？

编辑，记录：http://pastebin.com/kqG28NGH

感谢您的帮助！

Answer 1

这对我有用...我试图模仿我认为你的形式。我用 8 个文件的队列进行了测试，每个文件的大小从 150K 到 400K 不等。我不太明白你想用进度条做什么。我的填充每个文件并为下一个文件重置，最后一次调用 DoUpload 时没有更多文件。希望这会有所帮助。

Imports System.IO
Imports System.Net

Public Class Form1
    Const info_srv As String = "ftp://example.com/SomeFolder/"
    Const usr As String = ""
    Const pass As String = ""

    Const mc_dir As String = "D:\Source\Folder"

    Private WithEvents wc As New Net.WebClient

    ' Contains file names only, no paths
    Private Files As New Queue(Of String)

    Private Sub Button1_Click(sender As Object, e As EventArgs) _
        Handles Button1.Click

        wc.Credentials = New NetworkCredential(usr, pass)

        ' Put the work in a task so UI is responsive
        Task.Run(Sub() DoUpload())
    End Sub

    Private Sub DoUpload()
        ShowProgress("", 0)

        If Files.Count > 0 Then
            Dim local As String = Files.Dequeue
            Dim FileName As String = Path.Combine(mc_dir, local)

            AppendWarning("Uploading " & FileName & "...   ")

            Try
                wc.UploadFileAsync(New Uri(info_srv & local), FileName)
            Catch ex As Exception
                AppendWarning("-ERR: Could not upload file: " & local & Environment.NewLine)
            End Try
        Else
            AppendWarning("All Uploads Finished!" & Environment.NewLine)
        End If
    End Sub

    Private Sub wc_UploadProgressChanged(sender As Object, e As UploadProgressChangedEventArgs) _
        Handles wc.UploadProgressChanged

        ' Do not use e.ProgressPercentage - it's inaccurate by half by design per Microsoft
        With String.Format("{0} KB / {1} KB", Int(e.BytesSent / 1024).ToString("N0"), Int(e.TotalBytesToSend / 1024).ToString("N0"))
            ShowProgress(.ToString, Int(e.BytesSent / e.TotalBytesToSend * 100))
        End With

    End Sub

    Private Sub wc_UploadFileCompleted(sender As Object, e As UploadFileCompletedEventArgs) _
        Handles wc.UploadFileCompleted

        Select Case True
            Case e.Cancelled
                MessageBox.Show("Cancelled")
            Case e.Error IsNot Nothing
                MessageBox.Show(e.Error.Message)
            Case Else
                AppendWarning("Upload Complete!" & Environment.NewLine)

                ' I needed this just so I could see it work, otherwise too fast
                Threading.Thread.Sleep(500)

                DoUpload()
        End Select
    End Sub

    Private Sub AppendWarning(ByVal Text As String)
        If Me.InvokeRequired Then
            Me.Invoke(Sub() AppendWarning(Text))
        Else
            tb_warnings.AppendText(Text)
        End If
    End Sub

    Private Sub ShowProgress(LabelText As String, Progress As Integer)
        If Me.InvokeRequired Then
            Me.Invoke(Sub() ShowProgress(LabelText, Progress))
        Else
            Me.lbl_progress.Text = LabelText
            Me.lbl_progress.Refresh()

            Me.ProgressBar1.Value = Progress
            Me.ProgressBar1.Refresh()
        End If
    End Sub
End Class

Answer 2

为了后代：

检查 VB 配置中的网络跟踪设置。我发现我使用了一个非常冗长的 catch-all 配置来进行跟踪，但似乎开销正在扼杀上传。从那以后，我找到了一个更精简的 focus-on-ftp 组 xml 来修改它，现在文件可以正确上传了。谢谢大家！

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