Progresso SFTP con SSH.NET

Question

VB2010 con SSH.NET https://sshnet.codeplex.com/ Ho scaricato e implementato la libreria per eseguire un download SFTP e funziona benissimo. Ho esaminato la documentazione e gli esempi e non vedo come implementare un download SFTP con il progresso. Voglio visualizzare l'avanzamento del download mentre si verifica. Finora ho:

Imports Renci.SshNet 
Imports System.IO 

     Using sftp As New SftpClient("0.0.0.0", 25, "id", "pwd") 
      'connect to the server 
      sftp.Connect() 

      'the name of the remote file we want to transfer to the PC 
      Dim remoteFileName As String = "/data/OUT/trips.txt" 

      'download the file as a memory stream and convert to a file stream 
      Using ms As New MemoryStream 
       'download as memory stream 
       sftp.DownloadFile(remoteFileName, ms) 

       'create a file stream 
       Dim fs As New FileStream("c:\mytrips.txt", FileMode.Create, FileAccess.Write) 

       'write the memory stream to the file stream 
       ms.WriteTo(fs) 

       'close file stream 
       fs.Close() 

       'close memory stream 
       ms.Close() 
      End Using 

      'disconnect from the server 
      sftp.Disconnect() 

      MsgBox("The file has been downloaded from the server.", MsgBoxStyle.Information) 
     End Using 

Modifica: ok Ho fatto qualche ricerca e ho trovato un esempio nel forum di discussione di codeplex. Ho imparato che c'è un'altra funzione di download che è asincrona che userò. È un buon approccio per visualizzare i progressi nella finestra di debug e anche un controllo progressbar. Sentiti libero di commentare.

Imports Renci.SshNet 
Imports System.IO 
Imports Renci.SshNet.Sftp 
Dim fileSize As Long 

Private Sub btnGo_Click(sender As Object, e As EventArgs) Handles btnGo.Click 
    Try 
     Using sftp As New SftpClient("0.0.0.0", 25, "id", "pwd") 
      'connect to the server 
      sftp.Connect() 

      'the name of the remote file we want to transfer to the PC 
      Dim remoteFileName As String = "/Data/OUT/Config.txt" 

      'check for existence of the file 
      Dim IsExists As Boolean = sftp.Exists(remoteFileName) 
      If IsExists Then 
       'get the attributes of the file (namely the size) 
       Dim att As Sftp.SftpFileAttributes = sftp.GetAttributes(remoteFileName) 
       fileSize = att.Size 

       'download the file as a memory stream and convert to a file stream 
       Using ms As New MemoryStream 
        'download as memory stream 
        'sftp.DownloadFile(remoteFileName, ms, AddressOf DownloadCallback) 'with download progress 
        'sftp.DownloadFile(remoteFileName, ms) 'without download progress 

        'here we try an asynchronous operation and wait for it to complete. 
        Dim asyncr As IAsyncResult = sftp.BeginDownloadFile(remoteFileName, ms) 
        Dim sftpAsyncr As SftpDownloadAsyncResult = CType(asyncr, SftpDownloadAsyncResult) 
        While Not sftpAsyncr.IsCompleted 
         Dim pct As Integer = CInt((sftpAsyncr.DownloadedBytes/fileSize) * 100) 
         Debug.Print("Downloaded {0} of {1} ({2}%).", sftpAsyncr.DownloadedBytes, fileSize, pct) 
         pgbMain.Value = pct 

         Application.DoEvents() 
        End While 
        sftp.EndDownloadFile(asyncr) 

        'create a file stream 
        Dim localFileName As String = "c:\" & Date.Now.ToString("yyyy-dd-MM_HHmmss") & "_test.txt" 
        Dim fs As New FileStream(localFileName, FileMode.Create, FileAccess.Write) 

        'write the memory stream to the file stream 
        ms.WriteTo(fs) 

        'close file stream 
        fs.Close() 

        'close memory stream 
        ms.Close() 
       End Using 

       'disconnect from the server 
       sftp.Disconnect() 

       'success 
       MsgBox("The file has been downloaded from the server.", MsgBoxStyle.Information) 
      Else 
       MsgBox("The file does not exist on the server.", MsgBoxStyle.Exclamation) 
      End If 
     End Using 
    Catch ex As Exception 
     MsgBox(ex.ToString, MsgBoxStyle.Critical) 
    Finally 
     Me.Cursor = Cursors.Default 
    End Try 
End Sub 

Il file di prova ha impiegato 0.4 secondi per il download, quindi è stato difficile vedere i progressi. I file più grandi testano davvero bene.

Answer 1

Ho fatto qualche ricerca e ho trovato un esempio nel forum di discussione di codeplex. Ho imparato che c'è un'altra funzione di download che è asincrona che userò. È un buon approccio per visualizzare i progressi nella finestra di debug e anche un controllo progressbar. Sentiti libero di commentare

Imports Renci.SshNet 
    Imports System.IO 
    Imports Renci.SshNet.Sftp 
    Dim fileSize As Long 

    Private Sub btnGo_Click(sender As Object, e As EventArgs) Handles btnGo.Click 
    Try 
     Using sftp As New SftpClient("0.0.0.0", 25, "id", "pwd") 
      'connect to the server 
      sftp.Connect() 

      'the name of the remote file we want to transfer to the PC 
      Dim remoteFileName As String = "/Data/OUT/Config.txt" 

      'check for existence of the file 
      Dim IsExists As Boolean = sftp.Exists(remoteFileName) 
      If IsExists Then 
       'get the attributes of the file (namely the size) 
       Dim att As Sftp.SftpFileAttributes = sftp.GetAttributes(remoteFileName) 
       fileSize = att.Size 

       'download the file as a memory stream and convert to a file stream 
       Using ms As New MemoryStream 
        'download as memory stream 
        'sftp.DownloadFile(remoteFileName, ms, AddressOf DownloadCallback) 'with download progress 
        'sftp.DownloadFile(remoteFileName, ms) 'without download progress 

        'here we try an asynchronous operation and wait for it to complete. 
        Dim asyncr As IAsyncResult = sftp.BeginDownloadFile(remoteFileName, ms) 
        Dim sftpAsyncr As SftpDownloadAsyncResult = CType(asyncr, SftpDownloadAsyncResult) 
        While Not sftpAsyncr.IsCompleted 
         Dim pct As Integer = CInt((sftpAsyncr.DownloadedBytes/fileSize) * 100) 
         Debug.Print("Downloaded {0} of {1} ({2}%).", sftpAsyncr.DownloadedBytes, fileSize, pct) 
         pgbMain.Value = pct 

         Application.DoEvents() 
        End While 
        sftp.EndDownloadFile(asyncr) 

        'create a file stream 
        Dim localFileName As String = "c:\" & Date.Now.ToString("yyyy-dd-MM_HHmmss") & "_test.txt" 
        Dim fs As New FileStream(localFileName, FileMode.Create, FileAccess.Write) 

        'write the memory stream to the file stream 
        ms.WriteTo(fs) 

        'close file stream 
        fs.Close() 

        'close memory stream 
        ms.Close() 
       End Using 

       'disconnect from the server 
       sftp.Disconnect() 

       'success 
       MsgBox("The file has been downloaded from the server.", MsgBoxStyle.Information) 
      Else 
       MsgBox("The file does not exist on the server.", MsgBoxStyle.Exclamation) 
      End If 
     End Using 
    Catch ex As Exception 
     MsgBox(ex.ToString, MsgBoxStyle.Critical) 
    Finally 
     Me.Cursor = Cursors.Default 
    End Try 
End Sub