使用ASP.NET核心websocket进行Unicode接收

我正在尝试使用ASP.NET core 1.1 websocket中间件构建一个websocket服务器，该中间件可以处理文本消息。我的策略是使用固定大小的缓冲区持续读取和解码，直到websocket消息结束。 中间件设置如下所示：

public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
    {
        loggerFactory.AddConsole(Configuration.GetSection("Logging"));
        loggerFactory.AddDebug();

        var logger = loggerFactory.CreateLogger("websocket");

        app.UseWebSockets();

        app.Use(async (http, next) =>
        {
            if (!http.WebSockets.IsWebSocketRequest)
            {
                await next();
                return;
            }

            var websocket = await http.WebSockets.AcceptWebSocketAsync();

            while (websocket.State == WebSocketState.Open)
            {
                var buffer = new ArraySegment<byte>(new byte[32]);
                var charbuffer = new char[32];
                try
                {
                    var sb = new StringBuilder();
                    var decoder = Encoding.UTF8.GetDecoder();

                    //aha, we got a message
                    var detectResult = await websocket.ReceiveAsync(buffer, CancellationToken.None);
                    var receiveResult = detectResult;

                    while (!receiveResult.EndOfMessage)
                    {
                        var charLen = decoder.GetChars(buffer.Array, 0, receiveResult.Count, charbuffer, 0);
                        logger.LogInformation($"Decoded {charLen} byte(s) from wire");
                        sb.Append(charbuffer, 0, charLen);
                        receiveResult = await websocket.ReceiveAsync(buffer, CancellationToken.None);
                    }
                    var charLenFinal = decoder.GetChars(buffer.Array, 0, receiveResult.Count, charbuffer, 0);
                    logger.LogInformation($"Decoded {charLenFinal} byte(s) from wire");
                    sb.Append(charbuffer, 0, charLenFinal);

                    var message = sb.ToString();
                    logger.LogInformation($"decoded message: {message}");
                    await websocket.SendAsync(new ArraySegment<byte>(Encoding.UTF8.GetBytes("got it")), WebSocketMessageType.Text, true, CancellationToken.None);
                }
                catch (Exception ex)
                {
                    logger.LogError(ex.Message);
                    logger.LogError(ex.InnerException?.Message ?? string.Empty);
                }
            }
        });
    }

这个错误的原因是什么？

我认为：

var charLenFinal = decoder.GetChars(buffer.Array, 0, receiveResult.Count, charbuffer, 0);

应该是：

var charLenFinal = decoder.GetChars(buffer.Array, 0, receiveResult.Count, charbuffer, 0, true);

自：

请记住，Decoder对象在调用之间保存状态 盖查斯。当应用程序使用数据流完成时，它 应将flush参数设置为true，以确保 信息被刷新。使用此设置，解码器将忽略无效 字节，并清除内部缓冲区

---

.

奇怪，这些似乎没有关系，这个错误只是说客户端断开了连接。你的客户有什么问题吗？@Tratcher我不这么认为。它适用于ASCII文本和Unicode，其大小小于缓冲区大小（本例中为32）

var charLenFinal = decoder.GetChars(buffer.Array, 0, receiveResult.Count, charbuffer, 0);

var charLenFinal = decoder.GetChars(buffer.Array, 0, receiveResult.Count, charbuffer, 0, true);