Signalr不在监视数据库中的更改.因此，当您仅在数据库中将用户设置为非活动状态时，这对Signalr毫无意义.您的3个客户端仍处于连接状态.

Signalr is not watching your database for changes. So when you just set the user to inactive in the database, it means nothing to Signalr. Your 3 clients are still connected.

要获得理想的结果，请在集线器中添加类似的内容

To get the desired result add something like this to your Hub

public override OnConnected()
{
  // Increase the active user count in the db 
  IHubContext context = GlobalHost.ConnectionManager.GetHubContext<ServerHub>();
  Clients.All.broadcastCount(DB.GetCount());
  return base.OnConnected();
}

public override OnDisconnected() 
{
    //Decrease the connected user count in the db
  IHubContext context = GlobalHost.ConnectionManager.GetHubContext<ServerHub>();
  Clients.All.broadcastCount(DB.GetCount());
  return base.OnDisconnected();
}

然后，当您连接和断开客户端连接时，集线器将通知连接的客户端.

Then when you connect and disconnect your clients, the hub will notify connected clients.

您将需要以SignalR捕获的方式断开连接，因此您不仅可以更改数据库中的标志.尝试从客户端调用 $.connection.hub.stop(); .

You will need to disconnect in a way that SignalR will catch, so you can't just change a flag in the database. Try calling $.connection.hub.stop(); from your client.

此链接对此有更详细的说明.

This link goes into more detail on it.

如果您说在数据库中更新后触发了 dependency_OnChange 事件，则不要调用 SendNotifications(); ，而是调用中心方法，特别是NotifyAllClients(...)

If you say the dependency_OnChange event is fired after you update in the database, then Instead of calling SendNotifications();, call a hub method, specifically NotifyAllClients(...)