如何在ASP.NET Core中的Startup.cs中注册RoleManager

Question

当我在调试模式下运行应用程序时，我的种子方法由于“丢失”服务而失败。错误信息是：

尚未注册类型“Microsoft.AspNetCore.Identity.RoleManager`1[Microsoft.AspNetCore.Identity.IdentityRole]”的服务。

有人可以帮我在StartUp.cs课堂上正确注册这项服务吗？谢谢！

角色配置.cs

public static class RolesConfig
{

    public static async Task InitialiseAsync(ApplicationDbContext context, IServiceProvider serviceProvider)
    {
        var roleManager = serviceProvider.GetRequiredService<RoleManager<IdentityRole>>();
        string[] roleNames = {"Admin", "Report", "Search"};
        foreach (var roleName in roleNames)
        {
            var roleExist = await roleManager.RoleExistsAsync(roleName);
            if (!roleExist)
                await roleManager.CreateAsync(new IdentityRole(roleName));
        }
    }
}

启动.cs

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.
    public void ConfigureServices(IServiceCollection services)
    {
        services.Configure<CookiePolicyOptions>(options =>
        {
            // This lambda determines whether user consent for non-essential cookies is needed for a given request.
            options.CheckConsentNeeded = context => true;
            options.MinimumSameSitePolicy = SameSiteMode.None;
        });
        services.AddDbContext<ApplicationDbContext>(options =>
            options.UseSqlServer(
                Configuration.GetConnectionString("DefaultConnection")));
        services.AddDefaultIdentity<IdentityUser>()
            .AddEntityFrameworkStores<ApplicationDbContext>();
        services.AddHttpClient();
        services.AddHttpClient<IExceptionServiceClient, ExceptionServiceClient>();

        services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
    }

Answer 1

我认为您错过了 AddRoleManager 的调用。这是我的类似设置，请尝试：

        services.AddIdentity<IdentityUser, IdentityRole>(o => {
            o.Password.RequiredLength = 8;
        })
        .AddRoles<IdentityRole>()
        .AddRoleManager<RoleManager<IdentityRole>>()
        .AddDefaultTokenProviders()
        .AddEntityFrameworkStores<ApplicationDbContext>();