/// <summary>
/// 使用WebSocket服务端
/// </summary>
/// <param name="app"></param>
/// <returns></returns>
public static IApplicationBuilder UseWebSocketServer(this IApplicationBuilder app)
{
IServiceProvider serviceProvider = app.ApplicationServices;
IHostApplicationLifetime hostApplicationLifetime = serviceProvider.GetService <IHostApplicationLifetime>();
WebSocketServerOptions option = serviceProvider.GetService <IOptions <WebSocketServerOptions> >().Value;
ILogger logger = serviceProvider.GetService <ILoggerFactory>().CreateLogger(typeof(WebSocketServerExtentions));
WebSocketServer webSocketServer = serviceProvider.GetService <WebSocketServer>();
app.UseWebSockets();
CancellationTokenSource cancellationTokenSource = new CancellationTokenSource();
hostApplicationLifetime.ApplicationStopping.Register(() => cancellationTokenSource.Cancel());
app.Use(async(context, next) =>
{
if (context.WebSockets.IsWebSocketRequest)
{
using WebSocket webSocket = await context.WebSockets.AcceptWebSocketAsync();
WebSocketConnection connection = new WebSocketConnection(
webSocketServer, webSocket, Guid.NewGuid().ToString(), serviceProvider);
webSocketServer.AddConnection(connection);
if (option.OnConnected != null)
{
await option.OnConnected(serviceProvider, connection);
}
logger.LogInformation("收到新的连接 当前连接数:{Count}", webSocketServer.ConnectionCount);
List <byte> bytes = new List <byte>();
try
{
while (true)
{
var buffer = new byte[1024];
WebSocketReceiveResult result = await webSocket.ReceiveAsync(new ArraySegment <byte>(buffer), cancellationTokenSource.Token);
if (result.CloseStatus.HasValue)
{
await webSocket.CloseAsync(result.CloseStatus.Value, result.CloseStatusDescription, CancellationToken.None);
break;
}
bytes.AddRange(new ArraySegment <byte>(buffer, 0, result.Count));
if (result.EndOfMessage)
{
//接收数据结束
var body = Encoding.UTF8.GetString(bytes.ToArray());
//使用内部总线转发，异步处理
await _busControl.Publish(new MessageReceivedEvent
{
ConnectionId = connection.Id,
Body = body
});
bytes.Clear();
}
}
}
catch (Exception ex)
{
if (ex is WebSocketException webSocketException && webSocketException.WebSocketErrorCode == WebSocketError.ConnectionClosedPrematurely)
{
//忽略
}
else
{
logger.LogError(ex, ex.Message);
}
}
finally
{
webSocketServer.RemoveConnection(connection);
logger.LogInformation("连接关闭[{ConnectionId}] 当前连接数:{Count}", connection.Id, webSocketServer.ConnectionCount);
}
}