Question

我正在使用vb.net下载文件并使用Tamir.SharpSsh，除了速度慢，下载3.5 kb文件大约需要50秒。我的问题是如何最好将等待功能放入2分钟，以确保下载文件。

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

Get File就是这个

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

Answer 1

将整个下载放入后台工作人员DoWork()函数中，并将布尔结果添加为eventargs变量的结果变量。然后处理后台工作程序的RunWorkerCompleted（）事件，并执行从那里下载后要执行的任何任务。这样就可以确保下载实际完成。

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

我从ssh下载了一个文件，但完成下载需要50秒

1 个答案: