我有一个ASP.NET Core 3.1 MVC解决方案，在其中我创建了一个类来收集解决方案中常用的函数。
我已经像这样在startup.cs中注册了该类：
services.AddSingleton<ITeamFunctions, TeamFunctions>();
这个类的接口（ITeamFunctions）如下：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
namespace PI.Interfaces
{
public interface ITeamFunctions
{
Task UpdateTeamStat(int teamId);
Task<float> CalculatePriceToPay();
}
}
而类本身是这样的：
using System.Linq;
using System.Security.Claims;
using System.Text.RegularExpressions;
using System.Threading;
using System.Threading.Tasks;
using System.Transactions;
namespace PI.Utility
{
public class TeamFunctions : ITeamFunctions
{
private readonly ApplicationDbContext _db;
private readonly UserManager<IdentityUser> _userManager;
private readonly IHttpContextAccessor _httpContextAccessor;
public TeamFunctions(ApplicationDbContext db, UserManager<IdentityUser> userManager, IHttpContextAccessor httpContextAccessor)
{
_db = db;
_userManager = userManager;
_httpContextAccessor = httpContextAccessor;
}
Task UpdateTeamStat(int teamId)
{
//code here
}
Task<float> CalculatePriceToPay();
{
//code here
}
在运行解决方案时，我遇到了以下错误：
System.AggregateException:“一些服务无法构建（在验证服务描述符“ServiceType：PI.Interfaces.ITeamFunctions Lifetime：Singleton ImplementationType：PI.Utility.TeamFunctions”时出现错误：在激活“PI.Utility.TeamFunctions”时，无法解析类型为“Microsoft.AspNetCore.Identity.UserManager`1[Microsoft.AspNetCore.Identity.IdentityUser]”的服务。）”
如果禁用TeamFunction中的IdentityUser注入，则会抱怨我的ApplicationDbContext。 我尝试在startup.cs中更改范围（将AddSingleton更改为AddScoped），但没有任何区别。 我在Core 2.2解决方案中有类似的架构，那里它可以正常工作。
想知道我漏掉了什么？
编辑： 完整的startup.cs如下：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Identity.UI;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.HttpsPolicy;
using Microsoft.EntityFrameworkCore;
using PI.Data;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using PI.Models;
using Microsoft.AspNetCore.Http;
using PI.Utility;
using PI.Interfaces;
using Microsoft.AspNetCore.Identity.UI.Services;
using PI.Service;
using PI.Installers;
namespace PI
{
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.AddDbContext<ApplicationDbContext>(options =>
options.UseSqlServer(
Configuration.GetConnectionString("DefaultConnection")));
services.AddDefaultIdentity<ApplicationUser>()
.AddRoles<IdentityRole>()
.AddEntityFrameworkStores<ApplicationDbContext>();
services.Configure<IdentityOptions>(options =>
{
// Default Password settings.
options.Password.RequireDigit = false;
options.Password.RequireLowercase = true;
options.Password.RequireNonAlphanumeric = false;
options.Password.RequireUppercase = false;
options.Password.RequiredLength = 6;
options.Password.RequiredUniqueChars = 0;
});
services.Configure<CookiePolicyOptions>(options =>
{
options.CheckConsentNeeded = context => false;
options.MinimumSameSitePolicy = SameSiteMode.None;
});
services.AddSession(options =>
{
options.Cookie.IsEssential = true;
options.IdleTimeout = TimeSpan.FromMinutes(60);
options.Cookie.HttpOnly = true;
});
services.AddSingleton<IEmailSender, EmailSender>();
services.Configure<EmailOptions>(Configuration);
services.AddSingleton<ITeamFunctions, TeamFunctions>();
services.AddControllersWithViews();
services.AddRazorPages().AddRazorRuntimeCompilation();
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
app.UseDatabaseErrorPage();
}
else
{
app.UseExceptionHandler("/Home/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.UseStaticFiles();
app.UseRouting();
app.UseSession();
app.UseAuthentication();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapAreaControllerRoute(
name: "admin",
areaName: "admin",
pattern: "Admin/{controller=User}/{action=Index}/{id?}"
);
endpoints.MapControllerRoute(
name: "default",
pattern: "{area=Main}/{controller=Home}/{action=Index}/{id?}");
endpoints.MapRazorPages();
});
app.UseCookiePolicy();
}
}
}