c# TCP通信编程

协议类

   public abstract class Protocol<TMessageType>
    {
        const int HEADER_SIZE = 4;

        public async Task<TMessageType> ReceiveAsync(NetworkStream networkStream)
        {
            var bodyLength = await ReadHeader(networkStream);
            AssertValidMessageLength(bodyLength);
            return await ReadBody(networkStream, bodyLength);
        }

        public async Task SendAsync<T>(NetworkStream networkStream, T message)
        {
            var (header, body) = Encode(message);
            await networkStream.WriteAsync(header, 0, header.Length);
            await networkStream.WriteAsync(body, 0, body.Length);
        }

        async Task<int> ReadHeader(NetworkStream networkStream)
        {
            var headerBytes = await ReadAsync(networkStream, HEADER_SIZE);
            return IPAddress.NetworkToHostOrder(BitConverter.ToInt32(headerBytes, 0));
        }

        async Task<TMessageType> ReadBody(NetworkStream networkStream, int bodyLength)
        {
            var bodyBytes = await ReadAsync(networkStream, bodyLength);
            return Decode(bodyBytes);
        }

        async Task<byte[]> ReadAsync(NetworkStream networkStream, int bytesToRead)
        {
            var buffer = new byte[bytesToRead];
            int bytesRead = 0;
            while (bytesRead < bytesToRead)
            {
                var newBytes = await networkStream.ReadAsync(buffer, bytesRead, buffer.Length);
                if (newBytes == 0)
                {
                    throw new Exception("Socket Closed");
                }
                bytesRead += newBytes;
            }
            return buffer;
        }

        protected (byte[] header, byte[] body) Encode<T>(T message)
        {
            var bodyBytes = EncodeBody(message);
            var headerBytes = BitConverter.GetBytes(IPAddress.HostToNetworkOrder(bodyBytes.Length));
            return (headerBytes, bodyBytes);
        }

        protected abstract TMessageType Decode(byte[] message);

        protected abstract byte[] EncodeBody<T>(T messageType);

        protected virtual void AssertValidMessageLength(int messageLength)
        {
            if (messageLength < 1)
            {
                throw new Exception("Invalid Length");
            }
        }
    }

JSON协议类

   public class JsonMessageProtocal : Protocol<JObject>
    {
        static readonly JsonSerializer _serializer;
        static readonly JsonSerializerSettings _settings;

        static JsonMessageProtocal()
        {
            _settings = new JsonSerializerSettings
            {
                Formatting = Formatting.Indented,
                DateTimeZoneHandling = DateTimeZoneHandling.Utc,
                ContractResolver = new DefaultContractResolver
                {
                    NamingStrategy = new CamelCaseNamingStrategy
                    {
                        ProcessDictionaryKeys = false
                    }
                }
            };
            _serializer = JsonSerializer.Create(_settings);
        }

        protected override JObject Decode(byte[] message)
        {
            return JObject.Parse(Encoding.UTF8.GetString(message));
        }

        protected override byte[] EncodeBody<T>(T messageType)
        {
            var sb = new StringBuilder();
            var sr = new StringWriter(sb);
            _serializer.Serialize(sr, messageType);
            return Encoding.UTF8.GetBytes(sb.ToString());
        }
    }

XML协议类

TODO

通信信息适配

   [AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
    public class RouteAttribute : Attribute
    {
        public string Path { get; }

        public RouteAttribute(string path) => Path = path;
    }

    public abstract class MessageDispatcher<TMessageType> where TMessageType : class, new()
    {
        public abstract void Register<TParm, TResult>(Func<TParm, Task<TResult>> target);

        public abstract void Register<TParm>(Func<TParm, Task> target);

        public abstract Task<TMessageType> DispatchAsync(TMessageType message);
    }

    public class XDocumentMessageDispatch : MessageDispatcher<XDocument>
    {
        readonly List<(string xpathExpresstion, Func<XDocument, Task<XDocument>> targerMethod)> _handlers
            = new List<(string xpathExpresstion, Func<XDocument, Task<XDocument>> targerMethod)>();
        public override async Task<XDocument> DispatchAsync(XDocument message)
        {
            foreach (var (path, target) in _handlers)
            {
                if ((message.XPathEvaluate(path) as bool?) == true)
                {
                    return await target(message);
                }
            }
            return null;
        }

        public override void Register<TParm, TResult>(Func<TParm, Task<TResult>> target)
        {
            throw new NotImplementedException();
        }

        public override void Register<TParm>(Func<TParm, Task> target)
        {
            throw new NotImplementedException();
        }

        private string GetXPathRoute(MethodInfo methodInfo)
        {
            var routeAttribute = methodInfo.GetCustomAttribute<RouteAttribute>();
            if (routeAttribute == null)
                throw new ArgumentException($"Method { methodInfo.Name} missing required RouteAttribute");
            return $"boolean ({routeAttribute.Path})";
        }
    }