在.net core web網站中新增webSocket支援
注意：前置條件，作業系統 windows 8 以上，IIS Express 8.0 以上.
第1步：在Startup.cs檔案的頭部新增如下引用：
using System.Net.WebSockets;
using System.Threading;
using System.Threading.Tasks;
第2步：在Startup.cs檔案的Configure方法中增加以下程式碼
#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檔案中增加Echo方法。
程式碼如下：
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);
}