.net-core - 向特定用户发送 SignalR 消息

Question

我有一个 Blazor wasm 应用程序，它使用 SignalR 向客户端发送消息。当向所有客户端发送消息时，一切正常。为了向特定客户端发送消息，我想为每个客户端创建一个组:

public override async Task OnConnectedAsync()
        {
            //enter code here to keep track of connected clients
            var userName = Context.User.FindFirst(ClaimTypes.NameIdentifier); // get the username of the connected user
            
            await Groups.AddToGroupAsync(Context.ConnectionId, $"user_{userName}");
            
            await base.OnConnectedAsync();
        }

因此，在 Groups.AddToGroupAsync 中，我想添加 ConnectionId 和 userName。但是，创建连接时 userName 始终为 null。我应该如何在这里获得唯一的用户名？我的所有用户都是使用 .NET Core Identity 和 IdnetityServer 注册的。我还尝试了此方法的 [Authorize] 属性，但 userName 仍然为 null。

如果我在集线器类上使用 [Authorize] 属性，则从客户端连接到集线器时会收到 UnAuthorized 401 错误:

hubConnection = new HubConnectionBuilder()
            .WithUrl(NavigationManager.ToAbsoluteUri("/broadcaster"))
            .Build();
...
await hubConnection.StartAsync(); //returns 401 error

这是startup.cs:

using Microsoft.AspNetCore.Authentication;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.HttpsPolicy;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.ResponseCompression;
using Microsoft.EntityFrameworkCore;
using Microsoft.AspNetCore.Authorization;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using PakPx1.Server.Data;
using PakPx1.Server.Models;
using System;
using Syncfusion.Blazor;
using System.Linq;
using System.Threading.Tasks;
using PakPx1.Server.Hubs;
using PakPx1.Shared.Models;
using PakPx1.Client;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Formatters;
using PakPx1.Server.Utils;
using Microsoft.AspNetCore.SignalR;

namespace PakPx1.Server
{
    public class Startup
    {

        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        // For more information on how to configure your application, visit https://go.microsoft.com/fwlink/?LinkID=398940
        public void ConfigureServices(IServiceCollection services)
        {
            //services.AddDbContext<ApplicationDbContext>(options =>
            //    options.UseSqlServer(
            //        Configuration.GetConnectionString("DefaultConnection")));
            services.AddDatabaseDeveloperPageExceptionFilter();
            services.AddSyncfusionBlazor();
            services.AddDbContext<ApplicationDbContext>(options =>
            options.UseMySql(Configuration.GetConnectionString("DefaultConnection"), new MySqlServerVersion(new Version(5, 6, 48))));
            services.AddOptions();
            services.AddControllers();

            services.AddDefaultIdentity<ApplicationUser>(options => options.SignIn.RequireConfirmedAccount = true)
                .AddRoles<IdentityRole>()
                .AddEntityFrameworkStores<ApplicationDbContext>();


            services.AddIdentityServer()
                .AddApiAuthorization<ApplicationUser, ApplicationDbContext>(options =>
                {
                    options.IdentityResources["openid"].UserClaims.Add("role");
                    options.ApiResources.Single().UserClaims.Add("role");

                });


            services.AddAuthentication()
                .AddIdentityServerJwt();

            services.AddHttpContextAccessor();
            services.AddAuthorization();
            
            //services.AddSingleton<IUserIdProvider, NameUserIdProvider>();

            services.AddControllersWithViews();
            services.AddRazorPages();
            services.AddResponseCompression(opts =>
            {
                opts.MimeTypes = ResponseCompressionDefaults.MimeTypes.Concat(
                    new[] { "application/octet-stream" });
            });
            services.Configure<IdentityOptions>(options =>
            {
                // Password settings
                options.Password.RequireDigit = false;
                options.Password.RequiredLength = 4;
                options.Password.RequireNonAlphanumeric = false;
                options.Password.RequireUppercase = false;
                options.Password.RequireLowercase = false;

            });
            services.AddServerSideBlazor();
            services.AddResponseCompression(opts =>
            {
                opts.MimeTypes = ResponseCompressionDefaults.MimeTypes.Concat(
                    new[] { "application/octet-stream" });
            });
            services.AddMvc().AddMvcOptions(options =>
            {
                options.EnableEndpointRouting = false;
            });
            services.AddMvcCore(options => options.OutputFormatters.Add(new XmlSerializerOutputFormatter()));
            services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_3_0);
            services.AddMvc().AddXmlDataContractSerializerFormatters();
            services.AddSignalR();


            //services.AddCors(options =>
            //{
            //    options.AddPolicy("EnableCORS", builder =>
            //    {
            //        builder.AllowAnyOrigin().AllowAnyOrigin().AllowAnyHeader().AllowAnyMethod().AllowCredentials().Build();
            //    });
            //});
            //services.AddMvc(option => option.EnableEndpointRouting = false).SetCompatibilityVersion(CompatibilityVersion.Version_3_0);


        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env, IServiceProvider serviceProvider)
        {
            app.UseResponseCompression();

            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
                app.UseMigrationsEndPoint();
                app.UseWebAssemblyDebugging();
            }
            else
            {
                app.UseExceptionHandler("/Error");
                // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
                app.UseHsts();
            }

            app.UseHttpsRedirection();
            app.UseBlazorFrameworkFiles();
            app.UseStaticFiles();

            app.UseRouting();

            app.UseIdentityServer();
            app.UseAuthentication();
            app.UseAuthorization();

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapRazorPages();
                endpoints.MapControllers();
                endpoints.MapHub<Broadcaster>("/broadcaster");
                endpoints.MapFallbackToFile("index.html");
            });
            CreateRoles(serviceProvider).Wait();

        }

        private async Task CreateRoles(IServiceProvider serviceProvider)
        {
            var RoleManager = serviceProvider.GetRequiredService<RoleManager<IdentityRole>>();
            serviceProvider.GetRequiredService<UserManager<ApplicationUser>>();

            string[] roleNames = { "Admin", "Business Manager", "Client", "Settlement Manager", "VOTClient" };
            IdentityResult roleResult;

            foreach (var roleName in roleNames)
            {
                var roleExist = await RoleManager.RoleExistsAsync(roleName);
                if (!roleExist)
                {
                    roleResult = await RoleManager.CreateAsync(new IdentityRole(roleName));
                }
            }

        }




    }
}

Answer 1

您的简单答案将发送给具有 id 的特定用户:

Clients.Client(connectionId).SendAsync

但首先你需要保存所有连接ID，并在用户断开连接时删除ID。在您的集线器 Controller 中覆盖这些方法:

public static HashSet<UserInfoDto> Users = new HashSet<UserInfoDto>();

    public override Task OnConnectedAsync()
    {
        Users.Add(new UserInfoDto() { ConnectionId = Context.ConnectionId });
        return base.OnConnectedAsync();
    }

    public override async Task OnDisconnectedAsync(Exception exception)
    {
        var usr = Users.First(x => x.ConnectionId == Context.ConnectionId);
        Users.Remove(usr);

        if (!string.IsNullOrEmpty(usr.Name))
        {
            await UserContactListUpdate();
        }
        await base.OnDisconnectedAsync(exception);
    }

接下来您需要在登录、启动或其他状态后存储附加数据，例如我们需要在用户提交信息后添加登录信息，我们更新该用户的信息:

public async Task Login(string connectionId, string name, string imageId)
    {            
        var user = Users.First(x => x.ConnectionId == connectionId);

        if (string.IsNullOrEmpty(imageId))
        {                
            var path = Path.Combine(environment.ContentRootPath, "wwwroot", "images");
            var files = Directory.GetFiles(path, "*.png");
            var rnd = new Random();
            var index = rnd.Next(1, files.Length);

            imageId = Path.GetFileNameWithoutExtension(files[index]);
        }

        user.Name = name;
        user.ImageUrl = imageId;
        await Clients.Client(connectionId).SendAsync("LoginSucess", user);
        await UserContactListUpdate();
    }

我在 https://github.com/mahdiit/ChatServer 中编写了一个示例聊天服务器应用程序