ASP.NET Core WebSocket 提供了一種在客戶端和服務器之間進行全雙工通信的機制。以下是一些使用 ASP.NET Core WebSocket 的技巧：
安裝依賴項：確保安裝了 Microsoft.AspNetCore.Http.Abstractions 和 Microsoft.AspNetCore.WebSockets NuGet 包。
配置 WebSocket：在 Startup.cs 文件中配置 WebSocket 中間件。
public void ConfigureServices(IServiceCollection services)
{
services.AddControllersWithViews();
services.AddWebSocket(options =>
{
options.AllowedOrigins = new[] { "*" };
});
}
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
else
{
app.UseExceptionHandler("/Home/Error");
app.UseHsts();
}
app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseRouting();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllerRoute(
name: "default",
pattern: "{controller=Home}/{action=Index}/{id?}");
endpoints.MapWebSocket("/ws", new WebSocketOptions() { KeepAliveInterval = TimeSpan.Zero });
});
}
處理 WebSocket 連接：創建一個類來處理 WebSocket 連接和消息。
public class MyWebSocketHandler
{
private readonly WebSocket _webSocket;
public MyWebSocketHandler(WebSocket webSocket)
{
_webSocket = webSocket;
}
public async Task OnConnectedAsync(string userId)
{
await _webSocket.SendAsync(Encoding.UTF8.GetBytes($"Welcome, {userId}!"));
}
public async Task OnMessageReceivedAsync(string message)
{
var data = Encoding.UTF8.GetString(message);
await _webSocket.SendAsync(Encoding.UTF8.GetBytes($"Echo: {data}"));
}
public async Task OnDisconnectedAsync(Exception exception)
{
Console.WriteLine($"Disconnected: {exception}");
}
}
在控制器中使用 WebSocket：在控制器中處理 WebSocket 請求。
[HttpGet]
public async Task<IActionResult> Index(string id)
{
if (HttpContext.WebSockets.IsWebSocketRequest())
{
var webSocket = await HttpContext.WebSockets.AcceptWebSocketAsync();
var handler = new MyWebSocketHandler(webSocket);
await handler.OnConnectedAsync(id);
while (webSocket.State == WebSocketState.Open)
{
var buffer = new byte[1024 * 4];
WebSocketReceiveResult result;
do
{
result = await webSocket.ReceiveAsync(new ArraySegment<byte>(buffer), CancellationToken.None);
}
while (!result.CloseStatus.HasValue);
var message = Encoding.UTF8.GetString(buffer, 0, result.Count);
await handler.OnMessageReceivedAsync(message);
}
await handler.OnDisconnectedAsync(null);
}
return View();
}
客戶端代碼：在客戶端使用 JavaScript 建立 WebSocket 連接。
<!DOCTYPE html>
<html>
<head>
<title>WebSocket Example</title>
</head>
<body>
<input type="text" id="userId" placeholder="Enter your ID">
<script>
const userId = document.getElementById("userId").value;
const socket = new WebSocket("ws://localhost:5000/ws");
socket.addEventListener("open", (event) => {
socket.send(JSON.stringify({ userId }));
});
socket.addEventListener("message", (event) => {
const data = JSON.parse(event.data);
console.log(`Server says: ${data}`);
});
socket.addEventListener("close", (event) => {
console.log(`Disconnected: ${event}`);
});
</script>
</body>
</html>
這些技巧可以幫助你更好地使用 ASP.NET Core WebSocket 進行實時通信。
