将控制器方法重构为DI容器服务后无法被识别该如何解决？

开发者阿泽

2026-10-2

问题原因

1. 服务类存在自引用循环依赖：你的GetAZCredidentials类中定义了private readonly GetAZCredidentials _context;字段，构造函数未对该字段赋值，且后续用_context访问ApplicationUsers数据集，相当于让服务自己依赖自己，DI容器无法完成实例解析。
1. 缺失必要依赖注入：你需要访问数据库上下文，但代码中没有注入正确的DbContext实例，所有对_context.ApplicationUsers的调用都会触发报错。
1. 调用逻辑错误：你调用GetRequiredService获取的是服务类实例，直接和整数1做判断属于逻辑错误，需要调用实例下的GetAZCredidentials1()方法获取返回值再做判断。
1. （若存在）服务注册错误：如果未在Program.cs（.NET 6+）或Startup.cs的ConfigureServices方法中正确注册services.AddTransient<GetAZCredidentials>();，也会导致DI无法识别服务。
1. 调用时机错误：从调用栈看你是在Configure管道构建阶段调用服务解析，此时如果服务是Scoped生命周期，或者容器未完成构建，也会抛出解析异常。

修复步骤

修正服务类的依赖定义，注入正确的DbContext和IHttpContextAccessor：

namespace QlikviewServer.Services
{
    public class GetAZCredidentials
    {
        // 替换为你项目实际的DbContext类名
        private readonly YourDbContext _dbContext;
        private readonly IHttpContextAccessor _httpContextAccessor;

        public HttpContext HttpContext 
        { 
            get => _httpContextAccessor.HttpContext; 
            set => _httpContextAccessor.HttpContext = value; 
        }

        public GetAZCredidentials(YourDbContext dbContext, IHttpContextAccessor httpContextAccessor)
        {
            _dbContext = dbContext;
            _httpContextAccessor = httpContextAccessor;
        }

        public int GetAZCredidentials1()
        {
            PrincipalContext ctx = new PrincipalContext(ContextType.Domain);
            UserPrincipal user1 = UserPrincipal.Current;

            string displayName2 = user1.DisplayName;
            string displayName = user1.SamAccountName;
            string DistinguishedName = user1.DistinguishedName;
            string[] values = DistinguishedName.Split(',');
            string domain = values[6];
            string[] values2 = domain.Split('=');
            string domain2 = values2[1].Trim();
            string UserPrincipalName2 = user1.UserPrincipalName;
            var comp = values[4];
            var company_id = comp.Split('=');
            var company_id2 = company_id[1].Trim();
            List<ApplicationUser> groupsad = (from m in _dbContext.ApplicationUsers
                                              select new ApplicationUser { ApplicationUserId = m.ApplicationUserId, UserName = m.UserName, NameAdmin = m.NameAdmin, DisplayName = m.DisplayName, UserPrincipalName = m.UserPrincipalName }).ToList();

            var groups2 = (from m in _dbContext.ApplicationUsers
                           select m).ToList();

            for (int i = 0; i < groupsad.Count; i++)
            {
                if (string.IsNullOrEmpty(groupsad[i].NameAdmin.Trim()))
                {
                    groupsad[i].NameAdmin = groupsad[i].NameAdmin.Trim();
                }
                if (string.IsNullOrEmpty(groupsad[i].UserName.Trim()))
                {
                    groupsad[i].UserName = groupsad[i].UserName.Trim();
                }

                _dbContext.ApplicationUsers.Where(it => it.NameAdmin == groupsad[i].NameAdmin).ToList()
                  .ForEach(
                       it =>
                       {
                           var it2 = it.NameAdmin.TrimEnd();
                           if (it2 == displayName)
                           {
                               it.DisplayName = displayName2;
                           }
                       }
                    );

                if (string.IsNullOrEmpty(groupsad[i].UserPrincipalName.Trim()))
                {
                    _dbContext.ApplicationUsers.Where(it => it.NameAdmin == groupsad[i].NameAdmin).ToList()
                   .ForEach(
                        it =>
                        {
                            var it2 = it.NameAdmin.TrimEnd();
                            if (it2 == displayName)
                            {
                                it.UserPrincipalName = UserPrincipalName2;
                            }
                        }
                        );
                }
                else
                {
                    groupsad[i].UserPrincipalName = groupsad[i].UserPrincipalName.Trim();
                }
            }
            foreach (ApplicationUser f in groupsad)
            {
                if (f.NameAdmin.Trim() == displayName)
                {
                    if (f.UserName.Trim() == "reader" || (f.UserName.Trim() == "admin" && domain2 == "Vionet"))
                    {
                        return 1;
                    }
                }
                return 2;
            }
            return 3;
        }
    }
}

注册相关服务：
如果是.NET 6+版本，在Program.cs的服务注册阶段添加以下代码：

// 注册IHttpContextAccessor
builder.Services.AddHttpContextAccessor();
// 注册自定义服务
builder.Services.AddTransient<GetAZCredidentials>();

如果是.NET 5及以下版本，在Startup.cs的ConfigureServices方法里添加：

services.AddHttpContextAccessor();
services.AddTransient<GetAZCredidentials>();

修正调用逻辑：

// 获取服务实例
var azService = serviceProvider.GetRequiredService<GetAZCredidentials>();
// 调用方法获取返回值
var result1 = azService.GetAZCredidentials1();
if (result1 != 1)
{
    // 你的业务逻辑
}

如果是在Configure管道阶段调用，需要手动创建Scope：

app.Use(async (context, next) =>
{
    using var scope = context.RequestServices.CreateScope();
    var azService = scope.ServiceProvider.GetRequiredService<GetAZCredidentials>();
    var result1 = azService.GetAZCredidentials1();
    // 逻辑处理
    await next();
});

内容的提问来源于stack exchange，提问作者Aris Biris