Websocket Server and Client for VB.NET that can send multiple files bidirectionally with progress bar
Sending files programmatically has always been something that involves a tedious amount of work. Of course, there's great cloud tools like Google Drive or Dropbox. However, for enterprise solution, sometimes a dedicated solution is more secure and has lower latency. This repo contains a demonstration program that sends and receives files within itself. Obviously, the server and client can be split into 2 applications and run on separate machines.
Make sure to have the BlazingWebsockets file in your VB.NET program. Then include it in your main code:
Imports FileWebsockets.BlazingWebsocketsNow implement the interfaces to attach the callbacks to your code. You'll want to rate limit your UI updates as shown, so that the form doesn't freeze up:
Implements IBlazingWebsocketsCallbacks
Private websockets As BlazingWebsockets
Dim lastUpdateServer As DateTime = DateTime.MinValue
Dim lastUpdateClient As DateTime = DateTime.MinValue
Public Sub UpdateServerInterface(details As TransferInfo) Implements IBlazingWebsocketsCallbacks.UpdateServerInterface
Me.Invoke(Sub()
Dim rawPercent As Double = (details.bytesCurrent / details.bytesTotal) * 100
Dim percent As Integer = CInt(Math.Max(0, Math.Min(100, rawPercent))) 'constrain between 0-100
ProgressBar1.Value = percent
Dim now = DateTime.Now
If (now - lastUpdateServer).TotalMilliseconds > 300 Or percent > 98 Then
Dim humanRecvBytes As String = websockets.BytesToString(details.bytesCurrent)
Dim humanTotalFileSize As String = websockets.BytesToString(details.bytesTotal)
lblServerProgress.Text = percent.ToString & "% (" & humanRecvBytes & " of " & humanTotalFileSize & ")"
lblServerStatus.Text = details.status
Me.Refresh()
lastUpdateServer = now
End If
End Sub)
End Sub
Public Sub UpdateClientInterface(details As TransferInfo) Implements IBlazingWebsocketsCallbacks.UpdateClientInterface
Me.Invoke(Sub()
Dim rawPercent As Double = (details.bytesCurrent / details.bytesTotal) * 100
Dim percent As Integer = CInt(Math.Max(0, Math.Min(100, rawPercent))) 'constrain between 0-100
ProgressBar2.Value = percent
Dim now = DateTime.Now
If (now - lastUpdateClient).TotalMilliseconds > 500 Or percent > 98 Then
Dim humanRecvBytes As String = websockets.BytesToString(details.bytesCurrent)
Dim humanTotalFileSize As String = websockets.BytesToString(details.bytesTotal)
lblClientProgress.Text = percent.ToString & "% (" & humanRecvBytes & " of " & humanTotalFileSize & ")"
lblClientStatus.Text = details.status
Me.Refresh()
lastUpdateClient = now
End If
End Sub)
End Sub
Public Sub ServerIncomingMsg(msg As String) Implements IBlazingWebsocketsCallbacks.ServerIncomingMsg
Me.Invoke(Sub()
appendServerLog(msg)
End Sub)
End Sub
Public Sub ClientIncomingMsg(msg As String) Implements IBlazingWebsocketsCallbacks.ClientIncomingMsg
Me.Invoke(Sub()
appendClientLog(msg)
End Sub)
End SubThen write this to initiate the server:
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
websockets = New BlazingWebsockets(Me)
End SubOptionally, add these helper functions to print out the logs from the server/client:
Private Sub appendServerLog(ByVal line As String)
' Append the new text and a new line
RichTextBox1.AppendText(line & Environment.NewLine)
' Scroll to the bottom
RichTextBox1.SelectionStart = RichTextBox1.TextLength
RichTextBox1.ScrollToCaret()
End Sub
Private Sub appendClientLog(ByVal line As String)
' Append the new text and a new line
RichTextBox2.AppendText(line & Environment.NewLine)
' Scroll to the bottom
RichTextBox2.SelectionStart = RichTextBox2.TextLength
RichTextBox2.ScrollToCaret()
End SubTo specify your host/port and start the respective server/client, do the following:
Private Sub btnStartServer_Click(sender As Object, e As EventArgs) Handles btnStartServer.Click
websockets.serverPort = txtServerPort.Text
websockets.StartServer()
End Sub
Private Sub btnStartClient_Click(sender As Object, e As EventArgs) Handles btnStartClient.Click
websockets.clientHost = txtClientHost.Text
websockets.clientPort = txtClientPort.Text
websockets.StartClient()
End Sub
To send text or files from server/client respectively, do the following:
Private Async Sub btnServerSendFiles_ClickAsync(sender As Object, e As EventArgs) Handles btnServerSendFiles.Click
Dim filesList As List(Of String) = ListBox1.Items.Cast(Of String)().ToList()
Await websockets.ServerSendFiles(websockets.setClientID, filesList)
End Sub
Private Async Sub btnClientSendFiles_ClickAsync(sender As Object, e As EventArgs) Handles btnClientSendFiles.Click
Dim filesList As List(Of String) = ListBox2.Items.Cast(Of String)().ToList()
Await websockets.ClientSendFiles(websockets.clientWS, filesList)
End Sub
Private Async Sub btnServerSendText_ClickAsync(sender As Object, e As EventArgs) Handles btnServerSendText.Click
Dim clientID As String = websockets.lastClientID
Await websockets.ServerSendString(websockets.clientSockets(lastClientID), txtServerText.Text)
End Sub
Private Async Sub btnClientSendText_ClickAsync(sender As Object, e As EventArgs) Handles btnClientSendText.Click
Await websockets.ClientSendString(websockets.clientWS, txtClientText.Text)
End Sub