在 SignalR 中将用户添加到 Hub 组

Question

我有一个基集线器 (HubBase) 类和两个从基类继承的不同集线器类（我们称之为 HubA 和 HubB）。我将所有共享连接方法保留到 HubBase。我只想向连接到相关集线器的相应客户端发送消息。出于这个原因，我会将相关用户添加到已连接的相应组中。例如，如果用户连接到 HubA，则应将此用户添加到 GroupA，如果连接到 HubB，则应添加 GroupB。下面是相关类中的方法：

HubBase：

public class HubBase : Hub
{
    public readonly static ConnectionMapping<string> _connections =
        new ConnectionMapping<string>();

    public override async Task OnConnected()
    {
        /* !!! Here I need the user to the given group name. But I cannot define groupName 
        parameter in this method due to "no suitable method found to override" error */
        await Groups.Add(Context.ConnectionId, "groupA");

        string name = Context.User.Identity.Name;
        _connections.Add(name, Context.ConnectionId);
        await base.OnConnected();
    }

    public override async Task OnDisconnected(bool stopCalled)
    {
        await Groups.Remove(Context.ConnectionId, "groupA");

        string name = Context.User.Identity.Name;
        _connections.Remove(name, Context.ConnectionId);
        await base.OnDisconnected(stopCalled);
    }
}

HubA：

public class HubA : HubBase
{
    private static IHubContext context = GlobalHost.ConnectionManager.GetHubContext<HubA>();

    public async Task SendMessage(string message)
    {
        await context.Clients.Group("groupA", message).sendMessage;
    }
}

HubB：

public class HubB : HubBase
{
    private static IHubContext context = GlobalHost.ConnectionManager.GetHubContext<HubB>();

    public async Task SendMessage(string message)
    {
        await context.Clients.Group("groupB", message).sendMessage;
    }
}

问题是：我需要将组名传递给基类中的 OnConnected() 方法，并在连接时将用户添加到这个给定的组。但是由于“找不到合适的方法来覆盖”错误，我无法在此方法中定义 groupName 参数。我应该将此参数从继承的类传递给基类的构造函数吗？还是有更聪明的方法？

更新：这是我试图从客户端传递的内容：

HubService.ts：

export class HubService {
    private baseUrl: string;
    private proxy: any;
    private proxyName: string = 'myHub';
    private connection: any;         

    constructor(public app: AppService) {
        this.baseUrl = app.getBaseUrl();
        this.createConnection();
        this.registerOnServerEvents();
        this.startConnection();
    }

    private createConnection() {
        // create hub connection
        this.connection = $.hubConnection(this.baseUrl);

        // create new proxy as name already given in top  
        this.proxy = this.connection.createHubProxy(this.proxyName);
    }

    private startConnection(): any {
        this.connection
            .start()
            .done((data: any) => {
                this.connection.qs = { 'group': 'GroupA' };
            })
    }
}

HubBase.cs：

public override async Task OnConnected()
{
    var group = Context.QueryString["group"]; // ! this returns null
    await Groups.Add(Context.ConnectionId, group);

    string name = Context.User.Identity.Name;
    _connections.Add(name, Context.ConnectionId);
    await base.OnConnected();
}

Answer 1

我通过以下方法解决了这个问题：

service.ts:

private startConnection(): any {

    //pass parameter viw query string
    this.connection.qs = { 'group': 'myGroup' }; 

    this.connection
        .start()
        .done((data: any) => {
            //
        })
}

HubBase.cs：

public class HubBase : Hub
{
    public readonly static ConnectionMapping<string> _connections =
        new ConnectionMapping<string>();

    public override async Task OnConnected()
    {
        var group = Context.QueryString["group"];

        //I tried to add the user to the given group using one of the following method
        await Groups.Add(Context.ConnectionId, group); 
        await AddToGroup(Context.ConnectionId, group);

        //other stuff
    }
}

https://docs.microsoft.com/en-us/aspnet/signalr/overview/guide-to-the-api/hubs-api-guide-javascript-client#how-to-configure-the-connection

但我无法从继承的集线器类中获取组，如 Cannot retrieve group in SignalR Hub 中所述。有什么帮助吗？

Answer 2

您可以在与 queryString 开始连接时将 Group 名称设置为 parameter。

在服务器端从Request获取。

更多信息：

SignalR Client How to Set user when start connection?

请在 ts:

中尝试此代码

export class HubService 
{
    hubConnection: HubConnection;
    constructor(public app: AppService) { this.startConnection();}

    private startConnection(): any 
    {
        let builder = new HubConnectionBuilder();
        this.hubConnection = builder.withUrl('http://localhost:12345/HubBase?group=GroupA').build();
        this.hubConnection.start().catch(() => console.log('error'););
    }
}