SFTP Progress with SSH.NET

Question

VB2010 with SSH.NET.

I've downloaded and implemented the library to do an SFTP download and it works great. I've been looking at the documentation and examples and just cannot see how to implement an SFTP download with progress. I want to display the progress of the download as it occurs. So far I have:

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

Edit: ok I've done some research and found an example in the codeplex discussion forum. Out of that I learned that there is another downloading function which is asynchronous which I will use. Its a good approach to displaying progress in the debug window and also a progressbar control. Feel free to comment.

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

My test file took 0.4 seconds to download so it was hard to see the progress. Larger files test really well.

Answer 1

I've done some research and found an example in the codeplex discussion forum. Out of that I learned that there is another downloading function which is asynchronous which I will use. Its a good approach to displaying progress in the debug window and also a progressbar control. Feel free to comment

    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