Vb.net 我有一个来自ssh的下载文件，但完成下载需要50秒

我正在使用vb.net下载一个文件，并使用Tamir.SharpSsh，它工作得很好，只是速度很慢，下载一个3.5 kb的文件大约需要50秒。我的问题是，如何最好地将等待函数设置为2分钟，以确保文件被下载

Public Function DownloadPricat() As Boolean
    Dim retVal As Boolean
    Dim PRICAT_CSV As String
    Dim sfilename As String = ""
    Dim ifilename As String

    utils = New ThreeSoftware.Configuration.Utilities.utilConfigurationLoader("CONFIGURATION FILES\GEMINI RELATED\SkechersImport.ini")

    Hostname = utils.GetIniSetting("SSH SECTION", "SSH_HOST", "")
    username = utils.GetIniSetting("SSH SECTION", "SSH_USERNAME", "")
    passsword = utils.GetIniSetting("SSH SECTION", "SSH_PASSWORD", "")
    port = utils.GetIniSetting("SSH SECTION", "SSH_PORT", "")
    HomeDirectoy = utils.GetIniSetting("SSH SECTION", "SSH_REMOTE_DIRECTORY", "")


    transfer = New wcSFtp(Hostname, Integer.Parse(port), username, passsword)

    PRICAT_CSV = utils.GetIniSetting("PATHS SECTION", "PRICAT_CSV", "")
    sfilename = utils.GetIniSetting("PATHS SECTION", "PRICAT_FILENAME", "")

    ifilename = PRICAT_CSV & "\" & sfilename
    If transfer.getFile(HomeDirectoy & "Pricat.edi", ifilename) = True Then
        MsgBox("Download Complete", vbInformation, "Import")
        retVal = True
    Else

        retVal = False
    End If

End Function

获取文件就是这样

Public Function getFile(ByVal remotePath As String, ByVal localFile As String) As Boolean
    Try
        transfer = New Sftp(Me._hostname, Me._username, Me._password)
        transfer.Connect(Me._port)
        transfer.Get(remotePath, localFile)
        transfer.Close()
        Return True
    Catch ex As Exception
        Debug.Print("Error downloading file: " & ex.ToString)
        Return False
    End Try
End Function

---

将整个下载内容放入backgroundworker的

DoWork（）

函数中，并将布尔结果添加为eventargs变量的结果变量。 然后处理backgroundworker的RunWorkerCompleted（）事件，并在从那里下载后执行您希望执行的任何任务。这样你就可以确保下载已经完成

Public Class Form1
Private WithEvents LazyBGW As New System.ComponentModel.BackgroundWorker

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    'Initiate the backgroundworker. It runs in another thread.
    LazyBGW.RunWorkerAsync()
End Sub

Private Sub LazyBGW_DoWork(sender As Object, e As System.ComponentModel.DoWorkEventArgs) Handles LazyBGW.DoWork
    'This code runs in the BGW-Thread
    'Perform the whole download task here or just call your 
    e.Result = DownloadPricat()
    'Work is done, put results in the eventargs-variable for further processing
End Sub

Private Sub LazyBGW_RunWorkerCompleted(sender As Object, e As System.ComponentModel.RunWorkerCompletedEventArgs) Handles LazyBGW.RunWorkerCompleted
    'This code runs in the UI-Thread
    Dim results As Boolean = CBool(e.Result)
    MessageBox.Show("The worker is done and our result is: " & results.ToString)
End Sub
End Class

编辑： 在控制台应用程序中，您可以使用任务：

Module Module1
Private Function DownloadPricat() As Boolean
    Threading.Thread.Sleep(10000)
    Return True
End Function
Sub Main()
    Dim DLTask As New System.Threading.Tasks.Task(Of Boolean)(Function() DownloadPricat())
    DLTask.Start()
    Dim ThisTime As Date = Date.Now
    Console.Write("Downloading")
    While DLTask.IsCompleted = False AndAlso DLTask.IsCanceled = False AndAlso DLTask.IsFaulted = False
        If (Date.Now - ThisTime).TotalSeconds > 1 Then
            Console.Write(".")
            ThisTime = Date.Now
        End If
    End While
    Console.Write("Done.")
End Sub

---

结束模块

我强烈建议不要延迟，以确保完成某项工作。这会产生一种可能有效也可能无效的竞速状态，并且在最好的情况下会给用户造成不必要的额外等待时间。在最坏的情况下，在您的固定延迟后，任务仍然没有完成，并且出现了一些问题。如果3.5Kb下载需要一分钟，那么使用的库肯定有问题。使用更充分的SFTP客户端组件。这对gui应用程序正常工作，我还需要能够通过自动化来完成这项工作？在控制台应用程序中？在下载文件的过程中，你需要其他东西吗？我添加了一个控制台应用程序的示例。它不是控制台应用程序，只是winforms应用程序的auotmation类。我想我在这方面帮不了你。