asp.net-core - 如何在 Hub 外部获取 SignalR 核心中的当前 ClaimsPrincipal

Question

我有一个 SignalR Core 集线器，它依赖于服务。该服务本身有其自己的依赖项，其中之一需要访问当前的 ClaimsPrincipal。

我知道，我可以使用 Context.User 属性访问集线器内的 ClaimsPrincipal 并将其作为参数传递给服务，服务也可以将其作为参数传递等等。但我真的不喜欢通过将这种环境信息作为参数传递来污染服务 API。

我尝试使用 IHttpContextAccessor，如下所述:https://learn.microsoft.com/en-us/aspnet/core/migration/claimsprincipal-current?view=aspnetcore-2.2 这似乎适用于简单的 SignalR 设置，但它不适用于 Azure SignalR 服务，而这将是我们的生产设置。

有没有一种可靠的方法可以让 ClaimsPrincipal 脱离中心，同时适用于简单的本地设置和 Azure SignalR 服务？

Answer 1

在当前的 SignalR 版本 (1.1.0) 中不支持此功能。我创建了一个功能请求:https://github.com/dotnet/aspnetcore/issues/18657但被拒绝了。最终，我这样做了:

services.AddSingleton(typeof(HubDispatcher<>), typeof(HttpContextSettingHubDispatcher<>));

public class HttpContextSettingHubDispatcher<THub> : DefaultHubDispatcher<THub> where THub : Hub
{
    private readonly IHttpContextAccessor _httpContextAccessor;

    public HttpContextSettingHubDispatcher(IServiceScopeFactory serviceScopeFactory, IHubContext<THub> hubContext,
        IOptions<HubOptions<THub>> hubOptions, IOptions<HubOptions> globalHubOptions,
        ILogger<DefaultHubDispatcher<THub>> logger, IHttpContextAccessor httpContextAccessor) :
        base(serviceScopeFactory, hubContext, hubOptions, globalHubOptions, logger)
    {
        _httpContextAccessor = httpContextAccessor;
    }

    public override async Task OnConnectedAsync(HubConnectionContext connection)
    {
        await InvokeWithContext(connection, () => base.OnConnectedAsync(connection));
    }

    public override async Task OnDisconnectedAsync(HubConnectionContext connection, Exception exception)
    {
        await InvokeWithContext(connection, () => base.OnDisconnectedAsync(connection, exception));
    }

    public override async Task DispatchMessageAsync(HubConnectionContext connection, HubMessage hubMessage)
    {
        switch (hubMessage)
        {
            case InvocationMessage _:
            case StreamInvocationMessage _:
                await InvokeWithContext(connection, () => base.DispatchMessageAsync(connection, hubMessage));
                break;
            default:
                await base.DispatchMessageAsync(connection, hubMessage);
                break;
        }
    }

    private async Task InvokeWithContext(HubConnectionContext connection, Func<Task> action)
    {
        var cleanup = false;
        if (_httpContextAccessor.HttpContext == null)
        {
            _httpContextAccessor.HttpContext = connection.GetHttpContext();
            cleanup = true;
        }
        await action();
        if (cleanup)
        {
            _httpContextAccessor.HttpContext = null;
        }
    }
}