.net Core 中signalR的实现

下载nuget包，按照readme在Startup.cs中ConfigureServices方法中增加services.AddSignalR();
在Configure增加app.UseSignalR(u => u.MapHub("/chathub"));
npm install @aspnet/signalr 通过npm把signalr.js下到本地，然后添加到项目中。
然后创建hub类（集线器类）

public class Chat : Hub
    {
        /// 

        /// 向所有人推送消息
        /// 
        /// 
        /// 
        /// 
        public async Task SendMessage(string user, string message)
        {
            await Clients.All.SendAsync("ReceiveMessage", Context.ConnectionId, message);
        }
    }

创建index页面，用以下内容覆盖

@page

    
 
    

        
 
        

            User..........
            

            Message...
            
        
    
    

        

            

        
    
    

        
 
        

            

        
    

@*
    If you need a version of the chat script that is compatible with IE 11, replace the above 
*@

上面是客户端如何调用signalR的服务器端，同时也会存在controller需要访问服务器端，这么实现

	[Route("api")]
    [ApiController]
    public class ApiController : ControllerBase
    {
        private readonly IHubContext _hubContext;
        public ApiController(IHubContext hubContext)
        {
            _hubContext = hubContext;
        }

        [HttpPost,Route("send")]
        public string Create([FromBody] string value)
        {

            if (value == "gift")
            {
                _hubContext.Clients.All.SendCoreAsync("ReceiveMessage", new object[] { "giftCoupon", "Start" });
                Thread.Sleep(20000);
                return value;
            }
            else if (value == "end")
            {
                _hubContext.Clients.All.SendCoreAsync("ReceiveMessage", new object[] { "giftCoupon","Over"});
            }
            return "error";
        }
    }