NetCore WebSocket即时通讯示例

NetCore WebSocket 即时通讯示例，供大家参考，具体内容如下

1.新建Netcore Web项目

2.创建简易通讯协议

public class MsgTemplate

{

public string SenderID { get; set; }

public string ReceiverID { get; set; }

public string MessageType { get; set; }

public string Content { get; set; }

}

SenderID发送者ID

ReceiverID 接受者ID

MessageType 消息类型 Text Voice 等等

Content 消息内容

3.添加中间件ChatWebSocketMiddleware

100

101

102

103

104

105

public class ChatWebSocketMiddleware

{

private static ConcurrentDictionary<string, System.Net.WebSockets.WebSocket> _sockets = new ConcurrentDictionary<string, System.Net.WebSockets.WebSocket>();

private readonly RequestDelegate _next;

public ChatWebSocketMiddleware(RequestDelegate next)

{

_next = next;

}

public async Task Invoke(HttpContext context)

{

if (!context.WebSockets.IsWebSocketRequest)

{

await _next.Invoke(context);

return;

}

System.Net.WebSockets.WebSocket dummy;

CancellationToken ct = context.RequestAborted;

var currentSocket = await context.WebSockets.AcceptWebSocketAsync();

//string socketId = Guid.NewGuid().ToString();

string socketId = context.Request.Query["sid"].ToString();

if (!_sockets.ContainsKey(socketId))

{

_sockets.TryAdd(socketId, currentSocket);

}

//_sockets.TryRemove(socketId, out dummy);

//_sockets.TryAdd(socketId, currentSocket);

while (true)

{

if (ct.IsCancellationRequested)

{

break;

}

string response = await ReceiveStringAsync(currentSocket, ct);

MsgTemplate msg = JsonConvert.DeserializeObject<MsgTemplate>(response);

if (string.IsNullOrEmpty(response))

{

if (currentSocket.State != WebSocketState.Open)

{

break;

}

continue;

}

foreach (var socket in _sockets)

{

if (socket.Value.State != WebSocketState.Open)

{

continue;

}

if (socket.Key == msg.ReceiverID || socket.Key == socketId)

{

await SendStringAsync(socket.Value, JsonConvert.SerializeObject(msg), ct);

}

//_sockets.TryRemove(socketId, out dummy);

await currentSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, "Closing", ct);

currentSocket.Dispose();

}

private static Task SendStringAsync(System.Net.WebSockets.WebSocket socket, string data, CancellationToken ct = default(CancellationToken))

{

var buffer = Encoding.UTF8.GetBytes(data);

var segment = new ArraySegment<byte>(buffer);

return socket.SendAsync(segment, WebSocketMessageType.Text, true, ct);

}

private static async Task<string> ReceiveStringAsync(System.Net.WebSockets.WebSocket socket, CancellationToken ct = default(CancellationToken))

{

var buffer = new ArraySegment<byte>(new byte[8192]);

using (var ms = new MemoryStream())

{

WebSocketReceiveResult result;

do

{

ct.ThrowIfCancellationRequested();

result = await socket.ReceiveAsync(buffer, ct);

ms.Write(buffer.Array, buffer.Offset, result.Count);

}

while (!result.EndOfMessage);