在.net core web网站中添加webSocket支持

注意：前置条件，操作系统 windows 8 以上，IIS Express 8.0 以上.

第1步：在Startup.cs文件的头部添加如下引用：

using System.Net.WebSockets;

using System.Threading;

using System.Threading.Tasks;

第2步：在Startup.cs文件的Configure方法中增加以下代码

#region WebSocket

var webSocketOptions = new WebSocketOptions()

{

KeepAliveInterval = TimeSpan.FromSeconds(120),

ReceiveBufferSize = 4 * 1024,

};

app.UseWebSockets(webSocketOptions);

app.Use(async (context, next) =>

{

if (context.Request.Path == "/ws")

{

if (context.WebSockets.IsWebSocketRequest)

{

WebSocket webSocket = await context.WebSockets.AcceptWebSocketAsync();

await Echo(context, webSocket);

}

else

{

context.Response.StatusCode = 400;

await next();

}

}

else

{

await next();

}

});

#endregion

第3步：在Startup.cs文件中增加Echo方法。

代码如下：

private async Task Echo(HttpContext context, WebSocket webSocket)

{

var buffer = new byte[1024 * 4];

WebSocketReceiveResult result = await webSocket.ReceiveAsync(new ArraySegment<byte>(buffer), CancellationToken.None);

while (!result.CloseStatus.HasValue)

{

await webSocket.SendAsync(new ArraySegment<byte>(buffer, 0, result.Count), result.MessageType, result.EndOfMessage, CancellationToken.None);

result = await webSocket.ReceiveAsync(new ArraySegment<byte>(buffer), CancellationToken.None);

}

await webSocket.CloseAsync(result.CloseStatus.Value, result.CloseStatusDescription, CancellationToken.None);

}