cWebSocketServer Class Reference

📋 Class Overview

cWebSocketServer is a WebSocket server implementation class that provides functionality to listen on ports, manage multiple client connections, and broadcast messages.

📡 Event List

Event Name	Trigger Timing	Parameters
`OnStart`	Server started	`Port` (Listening port)
`OnStop`	Server stopped	None
`OnClientConnect`	New client connected	`ClientID`, `RemoteAddress`, `RemotePort`
`OnClientDisconnect`	Client disconnected	`ClientID`, `Reason`
`OnClientTextMessage`	Text message received from client	`ClientID`, `Message`
`OnClientBinaryMessage`	Binary message received from client	`ClientID`, `Data()`
`OnError`	Error occurred	`Description`

🔧 Property Reference

Port - Listening Port

Type: Long
Read/Write: Read-only

Description: The currently listening port number.

Example:

Debug.Print "Server listening port: " & m_Server.Port

IsListening - Is Listening

Type: Boolean
Read/Write: Read-only

Description: Whether the server is currently listening.

Example:

If m_Server.IsListening Then
    Debug.Print "Server is listening"
End If

ClientCount - Client Connection Count

Type: Long
Read/Write: Read-only

Description: Number of currently connected clients.

Example:

Debug.Print "Current connections: " & m_Server.ClientCount

' Update UI
lblClientCount.Caption = "Connections: " & m_Server.ClientCount

ClientIDs - Client ID Array

Type: Variant (String array)
Read/Write: Read-only

Description: Array of all connected client IDs.

Example:

' Get all client IDs
Dim vIDs() As Variant
vIDs = m_Server.ClientIDs

' Iterate all client IDs
Dim i As Long
For i = LBound(vIDs) To UBound(vIDs)
    Debug.Print "Client: " & vIDs(i)
Next i

🚀 Method Reference

Listen - Start Listening

Syntax:

Public Sub Listen(Optional ByVal Port As Long = 8080)

Parameters:

Parameter	Type	Description
`Port`	Long (Optional)	Listening port number, default 8080

Description:

If server is already listening, it will stop first then start
Triggers OnStart event after starting
Automatically initializes client collection

Example:

' Use default port 8080
m_Server.Listen

' Specify port
m_Server.Listen 9000

' Read port from config file
m_Server.Listen CLng(GetConfig("ServerPort"))

Error Handling:

Private Sub cmdStart_Click()
    On Error GoTo EH

    m_Server.Listen CLng(txtPort.Text)
    Debug.Print "Server started"
    Exit Sub

EH:
    Debug.Print "Start failed: " & Err.Description
    MsgBox "Cannot start server: " & Err.Description, vbExclamation
End Sub

StopServer - Stop Server

Syntax:

Public Sub StopServer()

Description:

Sends close frames to all clients
Closes all client connections
Clears client collection
Closes listening socket
Triggers OnStop event

Example:

' Stop server
m_Server.StopServer
Debug.Print "Server stopped"

' Auto stop on form close
Private Sub Form_Unload(Cancel As Integer)
    m_Server.StopServer
End Sub

SendText - Send Text Message

Syntax:

Public Sub SendText(ByVal ClientID As String, ByVal Message As String)

Parameters:

Parameter	Type	Description
`ClientID`	String	Target client ID
`Message`	String	Text message to send

Description: Sends text message to specified client. Message is automatically added WebSocket frame header, server sends without masking.

Example:

' Send welcome message
m_Server.SendText ClientID, "Welcome to WebSocket Server!"

' Echo message
m_Server.SendText ClientID, "Server received: " & Message

' Send JSON data
Dim sJSON As String
sJSON = "{""type"":""notification"", ""message"":""Hello""}"
m_Server.SendText ClientID, sJSON

' Send system message
m_Server.SendText ClientID, "[System] Server will maintain in 5 minutes"

SendBinary - Send Binary Message

Syntax:

Public Sub SendBinary(ByVal ClientID As String, Data() As Byte)

Parameters:

Parameter	Type	Description
`ClientID`	String	Target client ID
`Data()`	Byte()	Binary data to send

Example:

' Send image data
Dim baImage() As Byte
baImage = LoadImageAsByteArray()
m_Server.SendBinary ClientID, baImage

' Send file data
Dim baFile() As Byte
baFile = LoadFile("document.pdf")
m_Server.SendBinary ClientID, baFile

' Send serialized object
Dim baObj() As Byte
baObj = SerializeObject(myObject)
m_Server.SendBinary ClientID, baObj

BroadcastText - Broadcast Text Message

Syntax:

Public Sub BroadcastText(ByVal Message As String, Optional ByVal ExcludeClientID As String = "")

Parameters:

Parameter	Type	Description
`Message`	String	Text message to broadcast
`ExcludeClientID`	String (Optional)	Client ID to exclude (don't send to this client)

Description: Sends text message to all connected clients. Frame is built once then sent to all clients for better performance.

Example:

' Broadcast to all clients
m_Server.BroadcastText "Welcome to chat room!"

' Broadcast excluding sender
m_Server.BroadcastText Message, SenderClientID

' System announcement
m_Server.BroadcastText "[System] Server will restart in 5 minutes"

' Chat message broadcast
Private Sub m_Server_OnClientTextMessage(ByVal ClientID As String, ByVal Message As String)
    ' Broadcast message to all other clients, excluding sender
    m_Server.BroadcastText ClientID & ": " & Message, ClientID
End Sub

' Scheduled broadcast
Private Sub Timer1_Timer()
    Dim sTime As String
    sTime = Format$(Now, "yyyy-mm-dd hh:nn:ss")
    m_Server.BroadcastText "[Time] " & sTime
End Sub

BroadcastBinary - Broadcast Binary Message

Syntax:

Public Sub BroadcastBinary(Data() As Byte, Optional ByVal ExcludeClientID As String = "")

Parameters:

Parameter	Type	Description
`Data()`	Byte()	Binary data to broadcast
`ExcludeClientID`	String (Optional)	Client ID to exclude

Example:

' Broadcast image update
Dim baImage() As Byte
baImage = GetUpdatedImage()
m_Server.BroadcastBinary baImage

' Broadcast config file
Dim baConfig() As Byte
baConfig = SerializeConfig()
m_Server.BroadcastBinary baConfig

' Exclude sender
m_Server.BroadcastBinary baData, SenderClientID

DisconnectClient - Disconnect Client

Syntax:

Public Sub DisconnectClient(ByVal ClientID As String, _
                           Optional ByVal Code As WsCloseCode = WS_CLOSE_NORMAL, _
                           Optional ByVal Reason As String = "")

Parameters:

Parameter	Type	Description
`ClientID`	String	Client ID to disconnect
`Code`	WsCloseCode (Optional)	Close status code, default `WS_CLOSE_NORMAL`
`Reason`	String (Optional)	Close reason

Example:

' Normal disconnect
m_Server.DisconnectClient ClientID

' Specify close reason
m_Server.DisconnectClient ClientID, WS_CLOSE_GOING_AWAY, "Admin disconnect"

' Violating user disconnect
If IsViolation(ClientID) Then
    m_Server.DisconnectClient ClientID, WS_CLOSE_POLICY_VIOLATION, "Violating chat rules"
End If

' Disconnect all clients during maintenance
Private Sub PrepareForMaintenance()
    Dim vIDs() As Variant
    Dim i As Long
    vIDs = m_Server.ClientIDs
    
    For i = LBound(vIDs) To UBound(vIDs)
        m_Server.DisconnectClient vIDs(i), WS_CLOSE_GOING_AWAY, "Server maintenance"
    Next i
End Sub

📡 Event Details

OnStart - Server Started

Syntax:

Event OnStart(ByVal Port As Long)

Parameters:

Parameter	Type	Description
`Port`	Long	Listening port number

Example:

Private Sub m_Server_OnStart(ByVal Port As Long)
    Debug.Print "Server started, listening on port: " & Port
    
    ' Update UI
    lblStatus.Caption = "Running"
    lblPort.Caption = Port
    
    ' Log event
    LogEvent "Server started on port " & Port
    
    ' Start scheduled tasks
    Timer1.Enabled = True
End Sub

OnStop - Server Stopped

Syntax:

Event OnStop()

Example:

Private Sub m_Server_OnStop()
    Debug.Print "Server stopped"
    
    ' Update UI
    lblStatus.Caption = "Stopped"
    
    ' Log event
    LogEvent "Server stopped"
    
    ' Stop scheduled tasks
    Timer1.Enabled = False
End Sub

OnClientConnect - Client Connected

Syntax:

Event OnClientConnect(ByVal ClientID As String, ByVal RemoteAddress As String, ByVal RemotePort As Long)

Parameters:

Parameter	Type	Description
`ClientID`	String	Unique client identifier (format: `Client#N`)
`RemoteAddress`	String	Client IP address
`RemotePort`	Long	Client port

Example:

Private Sub m_Server_OnClientConnect(ByVal ClientID As String, ByVal RemoteAddress As String, ByVal RemotePort As Long)
    Debug.Print "Client connected: " & ClientID & " (" & RemoteAddress & ":" & RemotePort & ")"
    
    ' Add to client list
    lstClients.AddItem ClientID & " - " & RemoteAddress
    
    ' Send welcome message
    m_Server.SendText ClientID, "Welcome to WebSocket Server!"
    
    ' Send current online count
    m_Server.SendText ClientID, "Current online users: " & m_Server.ClientCount
    
    ' Broadcast new user online
    m_Server.BroadcastText "[System] " & ClientID & " is now online", ClientID
    
    ' Log connection
    LogConnection ClientID, RemoteAddress, RemotePort, "Connected"
    
    ' IP whitelist/blacklist check (should be during handshake)
    If IsBlacklisted(RemoteAddress) Then
        m_Server.DisconnectClient ClientID, WS_CLOSE_POLICY_VIOLATION, "IP blocked"
        LogConnection ClientID, RemoteAddress, RemotePort, "Blocked (Blacklist)"
    End If
End Sub

OnClientDisconnect - Client Disconnected

Syntax:

Event OnClientDisconnect(ByVal ClientID As String, ByVal Reason As String)

Parameters:

Parameter	Type	Description
`ClientID`	String	Client ID
`Reason`	String	Disconnect reason

Example:

Private Sub m_Server_OnClientDisconnect(ByVal ClientID As String, ByVal Reason As String)
    Debug.Print "Client disconnected: " & ClientID & " - " & Reason
    
    ' Remove from list
    Dim i As Long
    For i = 0 To lstClients.ListCount - 1
        If InStr(lstClients.List(i), ClientID) > 0 Then
            lstClients.RemoveItem i
            Exit For
        End If
    Next
    
    ' Update connection count
    UpdateClientCount
    
    ' Broadcast user offline
    m_Server.BroadcastText "[System] " & ClientID & " is now offline"
    
    ' Log disconnect
    LogDisconnect ClientID, Reason
    
    ' If VIP user, send notification
    If IsVIPClient(ClientID) Then
        NotifyAdmin "VIP user " & ClientID & " disconnected: " & Reason
    End If
End Sub

OnClientTextMessage - Text Message Received from Client

Syntax:

Event OnClientTextMessage(ByVal ClientID As String, ByVal Message As String)

Parameters:

Parameter	Type	Description
`ClientID`	String	Client ID sending the message
`Message`	String	Message content

Example:

Private Sub m_Server_OnClientTextMessage(ByVal ClientID As String, ByVal Message As String)
    Debug.Print "Received message from " & ClientID & ": " & Message
    
    ' Log message
    LogMessage ClientID, Message
    
    ' Handle command
    If Left$(Message, 1) = "/" Then
        ProcessCommand ClientID, Message
        Exit Sub
    End If
    
    ' Echo message
    m_Server.SendText ClientID, "Server received: " & Message
    
    ' Broadcast to other clients (chat mode)
    If m_bChatMode Then
        m_Server.BroadcastText ClientID & ": " & Message, ClientID
    End If
    
    ' Special command: broadcast
    If LCase$(Message) = "broadcast" Then
        m_Server.BroadcastText "This is a broadcast message from client " & ClientID, ClientID
    End If
End Sub

Private Sub ProcessCommand(ByVal ClientID As String, ByVal Command As String)
    Dim sCmd As String
    Dim sArgs() As String
    Dim sArgsList As String
    
    ' Parse command
    sCmd = LCase$(Mid$(Command, 2))
    sArgsList = Mid$(Command, 2)
    sArgs = Split(sArgsList, " ")
    
    Select Case sCmd
        Case "users"
            ' List all users
            Dim sUserList As String
            sUserList = "Online users: "
            Dim vIDs() As Variant
            vIDs = m_Server.ClientIDs
            Dim i As Long
            For i = LBound(vIDs) To UBound(vIDs)
                sUserList = sUserList & vIDs(i) & " "
            Next i
            m_Server.SendText ClientID, sUserList
            
        Case "time"
            ' Send server time
            m_Server.SendText ClientID, "Server time: " & Now
            
        Case "ping"
            ' Reply Pong
            m_Server.SendText ClientID, "pong"
            
        Case Else
            m_Server.SendText ClientID, "Unknown command: " & sCmd
    End Select
End Sub

OnClientBinaryMessage - Binary Message Received from Client

Syntax:

Event OnClientBinaryMessage(ByVal ClientID As String, Data() As Byte)

Parameters:

Parameter	Type	Description
`ClientID`	String	Client ID sending the message
`Data()`	Byte()	Binary data

Example:

Private Sub m_Server_OnClientBinaryMessage(ByVal ClientID As String, Data() As Byte)
    On Error Resume Next
    
    Debug.Print "Received binary message from " & ClientID & ": " & (UBound(Data) + 1) & " bytes"
    
    ' Log binary message
    LogBinaryMessage ClientID, UBound(Data) + 1
    
    ' Check data type (assume first 4 bytes are type identifier)
    If UBound(Data) >= 3 Then
        Dim lType As Long
        lType = CLng(Data(0)) * 256& ^ 3 + CLng(Data(1)) * 256& ^ 2 + _
                CLng(Data(2)) * 256& + CLng(Data(3))
        
        Select Case lType
            Case 1 ' Image upload
                SaveUploadedPicture ClientID, ExtractData(Data, 4)
                m_Server.SendText ClientID, "Image saved"
                
            Case 2 ' File upload
                SaveUploadedFile ClientID, ExtractData(Data, 4)
                m_Server.SendText ClientID, "File saved"
                
            Case 3 ' Custom data
                ProcessCustomData ClientID, ExtractData(Data, 4)
                
            Case Else
                Debug.Print "Unknown data type: " & lType
        End Select
    End If
End Sub

OnError - Error Occurred

Syntax:

Event OnError(ByVal Description As String)

Parameters:

Parameter	Type	Description
`Description`	String	Error description

Example:

Private Sub m_Server_OnError(ByVal Description As String)
    Debug.Print "Server error: " & Description
    
    ' Log error
    LogError Description
    
    ' Show error alert
    If m_bShowErrors Then
        MsgBox "Server error: " & Description, vbExclamation
    End If
    
    ' Stop server on critical error
    If InStr(Description, "critical") > 0 Then
        m_Server.StopServer
    End If
End Sub

📝 Complete Example

Basic Chat Server

Private WithEvents m_Server As cWebSocketServer
Private m_bChatMode As Boolean

Private Sub Form_Load()
    Set m_Server = New cWebSocketServer
    m_bChatMode = True
End Sub

Private Sub cmdStart_Click()
    m_Server.Listen CLng(txtPort.Text)
End Sub

Private Sub cmdStop_Click()
    m_Server.StopServer
End Sub

Private Sub m_Server_OnStart(ByVal Port As Long)
    Debug.Print "Server started: " & Port
    lblStatus.Caption = "Running"
End Sub

Private Sub m_Server_OnClientConnect(ByVal ClientID As String, ByVal RemoteAddress As String, ByVal RemotePort As Long)
    Debug.Print "Client connected: " & ClientID
    lstClients.AddItem ClientID
    m_Server.SendText ClientID, "Welcome to chat room!"
    m_Server.BroadcastText ClientID & " joined chat room", ClientID
End Sub

Private Sub m_Server_OnClientDisconnect(ByVal ClientID As String, ByVal Reason As String)
    Debug.Print "Client disconnected: " & ClientID
    Dim i As Long
    For i = 0 To lstClients.ListCount - 1
        If lstClients.List(i) = ClientID Then
            lstClients.RemoveItem i
            Exit For
        End If
    Next
    m_Server.BroadcastText ClientID & " left chat room"
End Sub

Private Sub m_Server_OnClientTextMessage(ByVal ClientID As String, ByVal Message As String)
    Debug.Print ClientID & ": " & Message
    txtLog.Text = txtLog.Text & ClientID & ": " & Message & vbCrLf
    
    ' Broadcast to all other clients
    m_Server.BroadcastText ClientID & ": " & Message, ClientID
End Sub

Private Sub m_Server_OnError(ByVal Description As String)
    Debug.Print "Error: " & Description
End Sub

Private Sub Form_Unload(Cancel As Integer)
    m_Server.StopServer
End Sub

Last Updated: 2026-01-10

cWebSocketServer Class Reference ​

📋 Class Overview ​

📡 Event List ​

🔧 Property Reference ​

Port - Listening Port ​

IsListening - Is Listening ​

ClientCount - Client Connection Count ​

ClientIDs - Client ID Array ​

🚀 Method Reference ​

Listen - Start Listening ​

StopServer - Stop Server ​

SendText - Send Text Message ​

SendBinary - Send Binary Message ​

BroadcastText - Broadcast Text Message ​

BroadcastBinary - Broadcast Binary Message ​

DisconnectClient - Disconnect Client ​

📡 Event Details ​

OnStart - Server Started ​

OnStop - Server Stopped ​

OnClientConnect - Client Connected ​

OnClientDisconnect - Client Disconnected ​

OnClientTextMessage - Text Message Received from Client ​

OnClientBinaryMessage - Binary Message Received from Client ​

OnError - Error Occurred ​

📝 Complete Example ​

Basic Chat Server ​

cWebSocketServer Class Reference

📋 Class Overview

📡 Event List

🔧 Property Reference

Port - Listening Port

IsListening - Is Listening

ClientCount - Client Connection Count

ClientIDs - Client ID Array

🚀 Method Reference

Listen - Start Listening

StopServer - Stop Server

SendText - Send Text Message

SendBinary - Send Binary Message

BroadcastText - Broadcast Text Message

BroadcastBinary - Broadcast Binary Message

DisconnectClient - Disconnect Client

📡 Event Details

OnStart - Server Started

OnStop - Server Stopped

OnClientConnect - Client Connected

OnClientDisconnect - Client Disconnected

OnClientTextMessage - Text Message Received from Client

OnClientBinaryMessage - Binary Message Received from Client

OnError - Error Occurred

📝 Complete Example

Basic Chat Server