c# - 在 Asp.net Core 中获取 UserManager 类的对象？

Question

using System;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Claims;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Identity;
using Services_Website.Models;
using Microsoft.AspNetCore.Mvc;
using Services_Website.Data;
using Microsoft.AspNetCore.Identity.EntityFrameworkCore;

namespace Services_Website.CustomFunctions
{
    public class CustomUserOperations: Controller
    {

        private UserManager<ApplicationUser> _userManager;
        public ApplicationUser GetCurrentUser()
        {
            ClaimsPrincipal currentUser = User;
            _userManager = new UserManager<ApplicationUser>();
            var user =_userManager.GetUserAsync(User).Result;
            return user;
        }
    }
}

* 这是我的 Controller *

我只想获取 UserManager 类的一个对象，但是当我这样做时，我得到了这个错误

Error CS7036 There is no argument given that corresponds to the required formal parameter 'store' of 'UserManager.UserManager(IUserStore, IOptions, IPasswordHasher, IEnumerable>, IEnumerable>, ILookupNormalizer, IdentityErrorDescriber, IServiceProvider, ILogger>)' Services_Website F:\webApplication\CoreApp\Services_Website\Services_Website\CustomFunctions\CustomUserOperations.cs 75 Active *

*错误来源是什么

Answer 1

可以使用依赖注入(inject)来获取 UserManager 类的实例。只需将参数添加到 Startup.cs 中的 Configure 方法即可。

public void Configure(IApplicationBuilder app, IHostingEnvironment env, 
    UserManager<ApplicationUser> userManager, RoleManager<IdentityRole> roleManager)
{}

然后在 Controller 中:

public class CustomUserOperations: Controller
{
     private UserManager<ApplicationUser> _userManager;
     CustomUserOperations(UserManager<ApplicationUser> userManager)
     {
         _userManager = userManager;
     }

     public ApplicationUser GetCurrentUser()
     {
         ClaimsPrincipal currentUser = User;
         var user =_userManager.GetUserAsync(User).Result;
         return user;
     }
}

您可以阅读更多关于 dependency injection here 的信息.