.NET 6控制台无DI使用UserManager生成重置令牌报错求助

问题描述 #

在.NET 6控制台应用中尝试不依赖依赖注入（DI）直接构造UserManager<ApplicationUser>实例，成功创建实例后，调用GeneratePasswordResetTokenAsync生成密码重置令牌时抛出错误：

No IUserTwoFactorTokenProvider named 'Default' is registered.

初始化UserManager的代码（Program.cs） #

IConfiguration config = new ConfigurationBuilder()
         .SetBasePath(Directory.GetCurrentDirectory())
         .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
         .AddEnvironmentVariables()
         .Build();

IServiceCollection services = new ServiceCollection();
services.AddTransient<UserManager<ApplicationUser>>();

var connectionStrings = config.GetSection("ConnectionStrings");
var messagingConnectionString = connectionStrings.GetValue<string>("Messaging");

AgentConfigDTO appSettingsDTO = new AgentConfigDTO()
        {
           ....
        };

services.AddDbContext<ApplicationDbContext>(options =>
            options.UseSqlServer(connectionStrings.ToString(),
            sqlServerOptionsAction: sqlOptions =>
            {
                sqlOptions.EnableRetryOnFailure(
                            maxRetryCount: 5,
                            maxRetryDelay: TimeSpan.FromSeconds(30),
                            errorNumbersToAdd: null);
            }
            ));

// Register UserManager & RoleManager
services.AddIdentity<IdentityUser, IdentityRole>();
services.AddIdentity<ApplicationUser, IdentityRole>(
            options =>
            {
                options.Tokens.ProviderMap.Add("Default", new TokenProviderDescriptor(typeof(IUserTwoFactorTokenProvider<ApplicationUser>)));
            })
           .AddEntityFrameworkStores<ApplicationDbContext>()
           .AddDefaultTokenProviders();

services.AddTransient<IUserStore<IdentityUser>, UserStore<IdentityUser>>();
services.AddTransient<UserManager<IdentityUser>>();

IServiceProvider serviceProvider = services.BuildServiceProvider();

var optionsBuilderApplication = new DbContextOptionsBuilder<ApplicationDbContext>();
var _applicationContext = new ApplicationDbContext(optionsBuilderApplication.UseSqlServer(connectionStrings.ToString()).Options);
     
IUserStore<ApplicationUser> store = new UserStore<ApplicationUser>(_applicationContext);
UserManager<ApplicationUser> userManager = new UserManager<ApplicationUser>(store, null, new PasswordHasher<ApplicationUser>(), null, null, null, null, serviceProvider, null);

// UserManager & RoleManager require logging and HttpContext dependencies
services.AddLogging();
services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();

new ReportAgent(appSettingsDTO, messagingConnectionString, userManager).RunAsConsole(args);

调用UserManager的方法代码 #

public void CheckingPasswords()
{
     try
     {               
         var date = DateTime.Now.AddMonths(-3);
         var userList = _applicationContext.Users.Where(t => t.PasswordExpiry != null && t.PasswordExpiry <= DateTime.Now.AddMonths(-3) && t.Deleted == false && t.PortalAccessEnabled == true).ToList();

         if (userList.Count > 0)
         {
             // Create email
             foreach (var user in userList)
             {
                 // Lock user out of the account
                 user.PortalAccessEnabled = false;
                 _applicationContext.Update(user);
                 _applicationContext.SaveChanges();

                 // Create email
                 // Exception is thrown on this line of code
                 var code = _userManager.GeneratePasswordResetTokenAsync(user).ToString(); 
                 var url = ""; // 原代码省略部分
                 var callbackUrl = url.Replace("[[id]]", user.Id).Replace("[[code]]", code);

                 Email email = new()
                        {
                            ... // 原代码省略部分
                        };
                 _dbContext.Add(email);
                 _dbContext.SaveChanges();
             }
         }
     }
}

已尝试的无效操作 #

手动添加Token Provider但未解决问题：

var identityBuilder = new IdentityBuilder(typeof(ApplicationUser), typeof(IdentityRole<string>), services);
identityBuilder.AddTokenProvider("Default", typeof(DataProtectorTokenProvider<ApplicationUser>));
services.AddTransient<UserManager<ApplicationUser>>();

解决方案 #

核心问题分析 #

1. 重复注册Identity服务：同时注册IdentityUser和ApplicationUser的AddIdentity，导致服务冲突，令牌提供器未正确绑定到ApplicationUser。
2. 手动构造UserManager缺少必要依赖：实例化时传入的令牌验证器、配置参数等为null，UserManager无法找到默认令牌提供器。
3. 服务提供器构建时机错误：在添加日志、IHttpContextAccessor等依赖前就构建了ServiceProvider，导致这些服务无法被UserManager使用。
4. 异步方法调用错误：直接对GeneratePasswordResetTokenAsync调用.ToString()，未等待异步完成，既拿不到正确令牌，也可能引发其他问题。

修正步骤 #

1. 清理并正确注册Identity服务

移除重复的AddIdentity<IdentityUser, IdentityRole>()，只保留ApplicationUser的Identity注册，确保自动添加默认令牌提供器：

// 移除这行无效注册：services.AddIdentity<IdentityUser, IdentityRole>();
services.AddIdentity<ApplicationUser, IdentityRole>()
       .AddEntityFrameworkStores<ApplicationDbContext>()
       .AddDefaultTokenProviders(); // 自动注册默认令牌提供器

2. 提前添加必要依赖并正确构建ServiceProvider

在构建ServiceProvider前添加日志、DataProtection等核心依赖（令牌生成依赖DataProtection加密）：

// 添加必要服务
services.AddLogging();
services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
services.AddDataProtection(); // 令牌加密需要此服务

// 最后构建服务提供器
IServiceProvider serviceProvider = services.BuildServiceProvider();

3. 通过ServiceProvider获取UserManager（推荐）

避免手动构造UserManager，直接从DI容器获取，确保所有依赖都正确注入：

var userManager = serviceProvider.GetRequiredService<UserManager<ApplicationUser>>();

4. 修正异步方法调用

将GeneratePasswordResetTokenAsync的调用改为异步等待，同时更新相关操作的异步方法：

// 方法需改为async
public async Task CheckingPasswords()
{
     try
     {               
         var date = DateTime.Now.AddMonths(-3);
         var userList = _applicationContext.Users.Where(t => t.PasswordExpiry != null && t.PasswordExpiry <= DateTime.Now.AddMonths(-3) && t.Deleted == false && t.PortalAccessEnabled == true).ToList();

         if (userList.Count > 0)
         {
             foreach (var user in userList)
             {
                 user.PortalAccessEnabled = false;
                 _applicationContext.Update(user);
                 await _applicationContext.SaveChangesAsync();

                 // 异步等待获取令牌
                 var code = await _userManager.GeneratePasswordResetTokenAsync(user); 
                 var url = "";
                 var callbackUrl = url.Replace("[[id]]", user.Id).Replace("[[code]]", code);

                 Email email = new()
                        {
                            ...
                        };
                 _dbContext.Add(email);
                 await _dbContext.SaveChangesAsync();
             }
         }
     }
}

（可选）如果必须手动构造UserManager

若一定要手动实例化，需传入所有必要依赖并手动注册令牌提供器：

var _applicationContext = new ApplicationDbContext(optionsBuilderApplication.UseSqlServer(connectionStrings.ToString()).Options);
IUserStore<ApplicationUser> store = new UserStore<ApplicationUser>(_applicationContext);

// 从服务容器获取必要依赖
var identityOptions = serviceProvider.GetRequiredService<IOptions<IdentityOptions>>().Value;
var tokenProvider = serviceProvider.GetRequiredService<IUserTwoFactorTokenProvider<ApplicationUser>>();
var logger = serviceProvider.GetRequiredService<ILogger<UserManager<ApplicationUser>>>();
var userValidators = new List<IUserValidator<ApplicationUser>> { new UserValidator<ApplicationUser>() };
var passwordValidators = new List<IPasswordValidator<ApplicationUser>> { new PasswordValidator<ApplicationUser>() };

// 实例化UserManager
UserManager<ApplicationUser> userManager = new UserManager<ApplicationUser>(
    store,
    identityOptions,
    new PasswordHasher<ApplicationUser>(),
    userValidators,
    passwordValidators,
    new UpperInvariantLookupNormalizer(),
    new IdentityErrorDescriber(),
    serviceProvider,
    logger);

// 手动注册默认令牌提供器
userManager.RegisterTokenProvider("Default", tokenProvider);

内容的提问来源于stack exchange，提问作者Raluca Micu