VB.NET【1】实现WebSocket【2】实时股票行情推送
随着互联网技术的不断发展，实时数据推送【3】已经成为许多应用场景中的关键技术。在金融领域，实时股票行情推送对于投资者来说至关重要。本文将介绍如何使用VB.NET语言结合WebSocket技术实现实时股票行情的推送。
WebSocket是一种在单个TCP连接【4】上进行全双工通信【5】的协议。它允许服务器和客户端之间进行实时数据交换，非常适合实现实时股票行情推送。本文将详细介绍如何使用VB.NET语言创建WebSocket服务器和客户端，实现股票行情的实时推送。
环境准备
在开始编写代码之前，我们需要准备以下环境：
1. Visual Studio 2019或更高版本
2. .NET Framework【6】 4.7.2或更高版本
WebSocket服务器端
1. 创建项目
在Visual Studio中创建一个新的VB.NET控制台应用程序项目。
2. 引入命名空间
在代码顶部引入必要的命名空间：
vb.net
Imports System.Net
Imports System.Net.Sockets
Imports System.Text
Imports System.Threading
Imports System.Threading.Tasks
Imports System.Web.WebSockets
3. 创建WebSocket服务器类
创建一个名为`WebSocketServer`的类，用于处理WebSocket连接和消息推送：
vb.net
Public Class WebSocketServer
Private ReadOnly _server As TcpListener
Private ReadOnly _clients As New List(Of WebSocket)
Public Sub New(ByVal ip As String, ByVal port As Integer)
_server = New TcpListener(New IPAddress(IPAddress.Parse(ip).GetAddressBytes()), port)
_server.Start()
End Sub
Public Sub Start()
Task.Run(Sub()
While True
Dim client As TcpClient = _server.AcceptTcpClient()
Dim webSocket As WebSocket = client.GetWebSocketStream()
_clients.Add(webSocket)
AddHandler webSocket.Opened, AddressOf WebSocket_Opened
AddHandler webSocket.Closed, AddressOf WebSocket_Closed
AddHandler webSocket.Error, AddressOf WebSocket_Error
AddHandler webSocket.DataReceived, AddressOf WebSocket_DataReceived
End While
End Sub)
End Sub
Private Sub WebSocket_Opened(sender As Object, e As WebSocketOpenEventArgs)
Console.WriteLine("Client connected.")
End Sub
Private Sub WebSocket_Closed(sender As Object, e As WebSocketCloseEventArgs)
Console.WriteLine("Client disconnected.")
_clients.Remove(sender)
End Sub
Private Sub WebSocket_Error(sender As Object, e As WebSocketErrorEventArgs)
Console.WriteLine("Error: " & e.Exception.Message)
End Sub
Private Sub WebSocket_DataReceived(sender As Object, e As WebSocketReceiveEventArgs)
Dim message As String = Encoding.UTF8.GetString(e.Body.ToArray())
Console.WriteLine("Received message: " & message)
' 处理接收到的消息
End Sub
Public Sub SendToAll(message As String)
For Each client As WebSocket In _clients
If client.State = WebSocketState.Open Then
client.SendAsync(New ArraySegment(Of Byte)(Encoding.UTF8.GetBytes(message)), WebSocketMessageType.Text, True, CancellationToken.None)
End If
Next
End Sub
Public Sub StopServer()
For Each client As WebSocket In _clients
client.CloseAsync(New WebSocketCloseEventArgs(WebSocketCloseStatus.NormalClosure, String.Empty), CancellationToken.None)
Next
_server.Stop()
End Sub
End Class
4. 启动服务器
在`Main`方法中创建`WebSocketServer`实例并启动服务器：
vb.net
Public Class Program
Public Shared Sub Main()
Dim server As New WebSocketServer("127.0.0.1", 8080)
server.Start()
Console.WriteLine("WebSocket server started. Press Enter to exit.")
Console.ReadLine()
server.StopServer()
End Sub
End Class
WebSocket客户端
1. 创建项目
在Visual Studio中创建一个新的VB.NET控制台应用程序项目。
2. 引入命名空间
在代码顶部引入必要的命名空间：
vb.net
Imports System.Net
Imports System.Net.Sockets
Imports System.Text
Imports System.Threading
Imports System.Threading.Tasks
Imports System.Web.WebSockets
3. 创建WebSocket客户端类
创建一个名为`WebSocketClient`的类，用于连接WebSocket服务器并接收消息：
vb.net
Public Class WebSocketClient
Private ReadOnly _client As TcpClient
Private ReadOnly _webSocket As WebSocket
Public Sub New(ByVal ip As String, ByVal port As Integer)
_client = New TcpClient(ip, port)
_webSocket = New WebSocket(_client.GetStream())
AddHandler _webSocket.Opened, AddressOf WebSocket_Opened
AddHandler _webSocket.Closed, AddressOf WebSocket_Closed
AddHandler _webSocket.Error, AddressOf WebSocket_Error
AddHandler _webSocket.DataReceived, AddressOf WebSocket_DataReceived
End Sub
Public Sub Connect()
_webSocket.OpenAsync(CancellationToken.None)
End Sub
Private Sub WebSocket_Opened(sender As Object, e As EventArgs)
Console.WriteLine("Connected to server.")
End Sub
Private Sub WebSocket_Closed(sender As Object, e As WebSocketCloseEventArgs)
Console.WriteLine("Disconnected from server.")
End Sub
Private Sub WebSocket_Error(sender As Object, e As WebSocketErrorEventArgs)
Console.WriteLine("Error: " & e.Exception.Message)
End Sub
Private Sub WebSocket_DataReceived(sender As Object, e As WebSocketReceiveEventArgs)
Dim message As String = Encoding.UTF8.GetString(e.Body.ToArray())
Console.WriteLine("Received message: " & message)
' 处理接收到的消息
End Sub
Public Sub Disconnect()
_webSocket.CloseAsync(New WebSocketCloseEventArgs(WebSocketCloseStatus.NormalClosure, String.Empty), CancellationToken.None)
End Sub
End Class
4. 连接服务器并接收消息
在`Main`方法中创建`WebSocketClient`实例，连接服务器并接收消息：
vb.net
Public Class Program
Public Shared Sub Main()
Dim client As New WebSocketClient("127.0.0.1", 8080)
client.Connect()
Console.WriteLine("Press Enter to exit.")
Console.ReadLine()
client.Disconnect()
End Sub
End Class
总结
本文介绍了如何使用VB.NET语言结合WebSocket技术实现实时股票行情推送。通过创建WebSocket服务器和客户端，我们可以实现服务器端实时推送股票行情，客户端实时接收并显示行情信息。在实际应用中，可以根据需要扩展功能，如添加股票数据源、实现用户认证等。
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