SFTP Progress with SSH.NET
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
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