c# - 在 SignalR hub 中存储特定客户端的连接 ID

Question

下面您可以看到我在 Windows 服务上的 SignalR 自托管中心的简化版本:

public static class SubscriptionHandler
{
    public static int PriceFeedMembersCount = 0;
}

public class PriceHub : Hub
{
    public Task SubscribeToPriceFeed()
    {
        IHubContext context = GlobalHost.ConnectionManager.GetHubContext<PriceHub>();
        if (SubscriptionHandler.PriceFeedMembersCount == 0)
        {
            context.Clients.All.updatePriceSubscriptionStatus(true);
        }
        SubscriptionHandler.PriceFeedMembersCount++;
        return context.Groups.Add(Context.ConnectionId, "PriceFeed");
    }

    public Task UnsubscribeFromPriceFeed()
    {
        IHubContext context = GlobalHost.ConnectionManager.GetHubContext<PriceHub>();
        SubscriptionHandler.PriceFeedMembersCount--;
        if (SubscriptionHandler.PriceFeedMembersCount == 0)
        {
            context.Clients.All.updatePriceSubscriptionStatus(false);
        }
        return context.Groups.Remove(Context.ConnectionId, "PriceFeed");
    }

    public void NotifySubscribers(Price price)
    {
        IHubContext context = GlobalHost.ConnectionManager.GetHubContext<PriceHub>();
        context.Clients.Group("PriceFeed").updatePrice(price);
    }
}

我有两种类型的中心客户端:一种是 Web 应用程序，另一种是 Windows 服务。在这里您可以看到我的 Windows 服务作为信号器客户端的演示实现:

public partial class WinSer45 : ServiceBase
{
    private HubConnection hubConnection;
    private IHubProxy priceProxy;
    private Timer timer = new Timer();
    private bool hasSubscribers = false;

    public WinSer45()
    {
        InitializeComponent();
    }

    protected override void OnStart(string[] args)
    {
        timer.Interval = 1000; // saniyede bir
        timer.Elapsed += timer_Elapsed;
        timer.Enabled = true;

        hubConnection = new HubConnection("http://localhost:8080/signalr", useDefaultUrl: false);
        priceProxy = hubConnection.CreateHubProxy("PriceHub");
        hubConnection.Start().Wait();
        priceProxy.On<bool>("UpdatePriceSubscriptionStatus", hasSubscribers =>
        {
            this.hasSubscribers = hasSubscribers;
        });
    }

    void timer_Elapsed(object sender, ElapsedEventArgs e)
    {   
        if (hasSubscribers)
        {
            TestPrice testPrice = new TestPrice() { Id = 1, Buy = 1.2345, Sell = 9.8765, Symbol = "EURUSD" };
            priceProxy.Invoke("NotifySubscribers", testPrice).Wait();    
        }
    }   

    protected override void OnStop()
    {
    }
}

如您所见，我使用 hasSubscribers 标志来最小化集线器和客户端之间的消息。 hasSubscribers 标志由 SubscribeToPriceFeed 和 UnsubscribeFromPriceFeed 方法更改。

如果仔细观察，您会在 SubscribeToPriceFeed 中看到以下行:

context.Clients.All.updatePriceSubscriptionStatus(true);

我不想将消息发送给除我的客户端 Windows 服务之外的所有客户端。如何将特定客户端的连接 ID 存储在我的集线器中？如果我能做到这一点，我知道我可以将消息发送到特定的 connectionId，如下所示:

context.Clients.Client(connectionId).updatePriceSubscriptionStatus(true);

提前致谢

Answer 1

在连接期间传递源

像这样

hubConnection = new HubConnection("http://localhost:8080/signalr","source=windows",useDefaultUrl: false);

集线器

public override Task OnConnected()
{
    var source= Context.QueryString['source'];
    return base.OnConnected();
}

创建一个类来保存用户的源代码

public class user {
  public string ConnectionID {set;get;}
  public string Source {set;get;}
}

在中心声明一个列表

List<user> userList=new List<user>();

然后在OnConnected期间推送用户

public override Task OnConnected()
{
    var us=new user();
    us.Source = Context.QueryString['source'];
    us.ConnectionID=Context.ConnectionId;
    userList.Add(us);
    return base.OnConnected();
}

在广播期间只需按来源过滤

var windowsUser=userList.Where(o=>o.Source == "windows").ToList(); // you'll get the windows user list