ASP.NET Core 3：无法从根提供程序解析作用域服务'Microsoft.AspNetCore.Identity.UserManager`1 [Alpha.Models.Identity.User]'

问题描述

在运行项目时，我遇到了这个问题：
（我使用过 asp.net core 3 。）

When I run the project, I encounter this problem:(I've used asp.net core 3.)

我该如何解决这个问题？

How can I solve this problem?

ApplicationDbContext类：

public class ApplicationDbContext : IdentityDbContext<User, Role, int, 
UserClaim, UserRole, UserLogin, RoleClaim, UserToken>
{
    public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options) : base(options)
    {

    }
public static async Task CreateAdminAccount(IServiceProvider 
serviceProvider, IConfiguration configuration)
    {
        UserManager<User> userManager = 
serviceProvider.GetRequiredService<UserManager<User>>();
        RoleManager<Role> roleManager = 
serviceProvider.GetRequiredService<RoleManager<Role>>();

        string userName = configuration["Data:AdminUser:Name"];
        string email = configuration["Data:AdminUser:Email"];
        string password = configuration["Data:AdminUser:Password"];
        string role = configuration["Data:AdminUser:Role"];

        if (await userManager.FindByNameAsync(userName) == null)
        {
            if (await roleManager.FindByNameAsync(role) == null)
            {
                await roleManager.CreateAsync(new Role(role));
            }

            User user = new User
            {
                Email = email,
                UserName = userName
            };
            var result = userManager.CreateAsync(user, password);
            if (result.IsCompletedSuccessfully)
            {
                await userManager.AddToRoleAsync(user, role);
            }
        }
    }
}

错误详细信息：

InvalidOperationException：无法解析作用域服务
'Microsoft.AspNetCore.Identity.UserManager`1 [Alpha.Models.Identity .User]'
来自根提供商。
Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteValidator.ValidateResolution（Type
serviceType，IServiceScope scope，IServiceScope rootScope）

InvalidOperationException: Cannot resolve scoped service 'Microsoft.AspNetCore.Identity.UserManager`1[Alpha.Models.Identity.User]' from root provider. Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteValidator.ValidateResolution(Type serviceType, IServiceScope scope, IServiceScope rootScope)

AggregateException：一个或多个错误发生了。 （无法从根提供商解析
作用域服务
'Microsoft.AspNetCore.Identity.UserManager`1 [Alpha.Models.Identity.User]'
。）
System.Threading。 Tasks.Task.ThrowIfExceptional（bool
includeTaskCanceledExceptions）System.Threading.Tasks.Task.Wait（int
millisecondsTimeout，CancellationToken cancelingToken）
System.Threading.Tasks.Task.Wait（）
Alpha.Web.App.Startup.Configure（IApplicationBuilder应用，
IWebHostEnvironment env）在Startup.cs中
+
ApplicationDbContext.CreateAdminAccount（app.ApplicationServices，
配置）。等待（）; System.RuntimeMethodHandle.InvokeMethod（对象
目标，object []参数，签名sig，布尔构造函数，布尔
wrapExceptions）System.Reflection.RuntimeMethodInfo.Invoke（对象obj，
BindingFlags invokeAttr，Binder活页夹，object []参数，
CultureInfo文化）
Microsoft.AspNetCore.Hosting.ConfigureBuilder.Invoke（对象实例，
IApplicationBuilder构建器）
Microsoft.AspNetCore.Hosting.ConfigureBuilder + <> c__DisplayClass4_0.b__0（IApplicationBuilder
构建器）
Microsoft.AspNetCore.Hosting.GenericWebHostBuilder +<> c__DisplayClass13_0.b__2（IApplicationBuilder
应用程序）
Microsoft.AspNetCore.Mvc。 Filters.MiddlewareFilterBuilderStartupFilter +<> c__DisplayClass0_0.g__MiddlewareFilterBuilder | 0（IApplicationBuilder
构建器）
Microsoft.AspNetCore.Server.IIS.Core.IISServerSetupFilter +<> c__DisplayClass2_0.b__0（IApplicationBuilder
应用程序）
Microsoft.AspNetCore.HostFilteringStartupFilter +<> c__ DisplayClass0_0.b__0（IApplicationBuilder
应用）
Microsoft.AspNetCore.Hosting.GenericWebHostService.StartAsync（CancellationToken
CancellationToken）
Microsoft.Extensions.Hosting.Internal.Host.StartAsync（CancellationToken
cancelleToken）
Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.RunAsync（IHost
主机，CancellationToken令牌）
Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.RunAsync（IHost
主机， CancellationToken令牌）
Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.Run（IHost
主机）Program.cs
+ $ b中的Alpha.Web.App.Program.Main（string [] args） $ b CreateHostBuilder（args）.Build（）。Run（）;

AggregateException: One or more errors occurred. (Cannot resolve scoped service 'Microsoft.AspNetCore.Identity.UserManager`1[Alpha.Models.Identity.User]' from root provider.) System.Threading.Tasks.Task.ThrowIfExceptional(bool includeTaskCanceledExceptions) System.Threading.Tasks.Task.Wait(int millisecondsTimeout, CancellationToken cancellationToken) System.Threading.Tasks.Task.Wait() Alpha.Web.App.Startup.Configure(IApplicationBuilder app, IWebHostEnvironment env) in Startup.cs + ApplicationDbContext.CreateAdminAccount(app.ApplicationServices, Configuration).Wait(); System.RuntimeMethodHandle.InvokeMethod(object target, object[] arguments, Signature sig, bool constructor, bool wrapExceptions) System.Reflection.RuntimeMethodInfo.Invoke(object obj, BindingFlags invokeAttr, Binder binder, object[] parameters, CultureInfo culture) Microsoft.AspNetCore.Hosting.ConfigureBuilder.Invoke(object instance, IApplicationBuilder builder) Microsoft.AspNetCore.Hosting.ConfigureBuilder+<>c__DisplayClass4_0.b__0(IApplicationBuilder builder) Microsoft.AspNetCore.Hosting.GenericWebHostBuilder+<>c__DisplayClass13_0.b__2(IApplicationBuilder app) Microsoft.AspNetCore.Mvc.Filters.MiddlewareFilterBuilderStartupFilter+<>c__DisplayClass0_0.g__MiddlewareFilterBuilder|0(IApplicationBuilder builder) Microsoft.AspNetCore.Server.IIS.Core.IISServerSetupFilter+<>c__DisplayClass2_0.b__0(IApplicationBuilder app) Microsoft.AspNetCore.HostFilteringStartupFilter+<>c__DisplayClass0_0.b__0(IApplicationBuilder app) Microsoft.AspNetCore.Hosting.GenericWebHostService.StartAsync(CancellationToken cancellationToken) Microsoft.Extensions.Hosting.Internal.Host.StartAsync(CancellationToken cancellationToken) Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.RunAsync(IHost host, CancellationToken token) Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.RunAsync(IHost host, CancellationToken token) Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.Run(IHost host) Alpha.Web.App.Program.Main(string[] args) in Program.cs + CreateHostBuilder(args).Build().Run();

显示原始异常详细信息InvalidOperationException：无法解析
作用域服务
'Microsoft .AspNetCore.Identity.UserManager`1 [Alpha.Models.Identity.User]'
来自根提供者。
Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteValidator.ValidateResolution（Type
serviceType，IServiceScope scope，IServiceScope rootScope）
Microsoft.Extensions.DependencyInjection.ServiceProvider.Microsoft.Extensions.DependencyInjection.ServiceLookup.IServiceProviderEngineCallback .OnResolve（Type
serviceType，IServiceScope scope）
Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngine.GetService（Type
serviceType，ServiceProviderEngineScope serviceProviderEngineScope）
Microsoft.Extensions.DependencyInjection.ServiceLookup .ServiceProviderEngineScope.GetService（Type
serviceType）
Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService（IServiceProvider
provider，Type serviceType）
Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService（ IServiceProvider
提供者）
Alpha.DataAccess.ApplicationDbC
中的ontext.CreateAdminAccount（IServiceProvider
serviceProvider，IConfiguration配置）
+
UserManager userManager = serviceProvider.GetRequiredService>（）;

Show raw exception details InvalidOperationException: Cannot resolve scoped service 'Microsoft.AspNetCore.Identity.UserManager`1[Alpha.Models.Identity.User]' from root provider. Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteValidator.ValidateResolution(Type serviceType, IServiceScope scope, IServiceScope rootScope) Microsoft.Extensions.DependencyInjection.ServiceProvider.Microsoft.Extensions.DependencyInjection.ServiceLookup.IServiceProviderEngineCallback.OnResolve(Type serviceType, IServiceScope scope) Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngine.GetService(Type serviceType, ServiceProviderEngineScope serviceProviderEngineScope) Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngineScope.GetService(Type serviceType) Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider provider, Type serviceType) Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider provider) Alpha.DataAccess.ApplicationDbContext.CreateAdminAccount(IServiceProvider serviceProvider, IConfiguration configuration) in ApplicationDbContext.cs + UserManager userManager = serviceProvider.GetRequiredService>();

显示原始异常详细信息System.InvalidOperationException：无法
解析作用域服务
'Microsoft.AspNetCore.Identity.UserManager`1 [Alpha.Models.Identity.User]'
来自根提供商。在
处Microsoft.Extensions.DependencyInjection.ServiceProvider.Microsoft.Extensions.DependencyInjection.ServiceLookup在
处Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteValidator.ValidateResolution（Type
serviceType，IServiceScope scope，IServiceScope rootScope） .IServiceProviderEngineCallback.OnResolve（Type
serviceType，IServiceScope scope）at
Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngine.GetService（Type
serviceType，ServiceProviderEngineScope serviceProviderEngineScope）

at
Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngineScope.GetService（Type
serviceType）at
Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService（IServiceProvider
provider，Type serviceType）at $ b b $ b Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService [T]（IServiceProvider
prov ider）在
中的
Alpha.DataAccess.ApplicationDbContext.CreateAdminAccount（IServiceProvider
serviceProvider，IConfiguration配置）E：\归档chi项目\Alpha\Alpha.DataAccess\ApplicationDbContext。 cs：line
92 .NET Core 3.0.0 X64 v4.0.0.0 | Microsoft.AspNetCore.Hosting
版本3.0.0-rc2.19465.2 | Microsoft Windows 10.0.17763 |

需要帮助吗？

Show raw exception details System.InvalidOperationException: Cannot resolve scoped service 'Microsoft.AspNetCore.Identity.UserManager`1[Alpha.Models.Identity.User]' from root provider. at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteValidator.ValidateResolution(Type serviceType, IServiceScope scope, IServiceScope rootScope) at Microsoft.Extensions.DependencyInjection.ServiceProvider.Microsoft.Extensions.DependencyInjection.ServiceLookup.IServiceProviderEngineCallback.OnResolve(Type serviceType, IServiceScope scope) at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngine.GetService(Type serviceType, ServiceProviderEngineScope serviceProviderEngineScope)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngineScope.GetService(Type serviceType) at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider provider, Type serviceType) at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService[T](IServiceProvider provider) at Alpha.DataAccess.ApplicationDbContext.CreateAdminAccount(IServiceProvider serviceProvider, IConfiguration configuration) in E:\Archives\Projects\Alpha\Alpha.DataAccess\ApplicationDbContext.cs:line 92 .NET Core 3.0.0 X64 v4.0.0.0 | Microsoft.AspNetCore.Hosting version 3.0.0-rc2.19465.2 | Microsoft Windows 10.0.17763 |
Need help?

推荐答案

在包含的屏幕截图中，它表明您在 Startup中获得了以下内容配置：

From the screenshot you've included, it shows that you've got the following line in Startup.Configure:

ApplicationDbContext.CreateAdminAccount(app.ApplicationServices, Configuration)
    .Wait();

IServiceProvider 实例= https://docs.microsoft.com/zh-cn/dotnet/api/microsoft.aspnetcore.builder.iapplicationbuilder.applicationservices?view=aspnetcore-3.0 rel = noreferrer> IApplicationBuilder。 ApplicationServices 是您的应用程序的 root 服务提供商。错误消息指出，它无法解析 root 服务提供商的作用域服务。

The IServiceProvider instance stored in IApplicationBuilder.ApplicationServices is the root service provider for your application. The error message states that it cannot resolve a scoped service from the root service provider.

出现此问题通常，但是针对您的方案最简单的解决方案是将 IServiceProvider 注入您的 Configure 方法并将其传递给 CreateAdminAccount ：

This issue comes up often, but the easiest solution for your scenario is to inject IServiceProvider into your Configure method and pass that into CreateAdminAccount:

public void Configure(IApplicationBuilder app, IServiceProvider serviceProvider)
{
    ApplicationDbContext.CreateAdminAccount(serviceProvider, Configuration)
        .Wait();
}

IServiceProvider的实例 Configure 的>是 scoped ，这意味着您可以使用它来创建范围服务。

The instance of IServiceProvider that gets passed into Configure is scoped, which means that you can use it to create scoped services.

这是完成这项工作所需的全部，但是在 Program 中进行此类播种更为典型。这样可以使关注点与配置管道分离，并且还允许使用 async / await 。下面是一个示例：

That's all you need to make this work, but it's more typical to do this type of seeding in Program. That keeps seeding concerns separate from configuring the pipeline and it also allows the use of async/await. Here's an example:

public class Program
{
    public static async Task Main(string[] args)
    {
        var host = CreateHostBuilder(args).Build();

        using (var scope = host.Services.CreateScope())
        {
            var serviceProvider = scope.ServiceProvider;
            var config = serviceProvider.GetRequiredService<IConfiguration>();

            await ApplicationDbContext.CreateAdminAccount(serviceProvider, config);
        }

        await host.RunAsync();
    }

    public static IHostBuilder CreateHostBuilder(string[] args) =>
        // ...
}

您可以解析<$ c $也将 Main 中的c> UserManager< User> 和 RoleManager< Role> 进入 CreateAdminAccount 的用户，而不是使用服务定位器方法的用户。

You could resolve UserManager<User> and RoleManager<Role> in Main too, and pass those in to CreateAdminAccount rather than having it use the service-locator approach.

这篇关于ASP.NET Core 3：无法从根提供程序解析作用域服务'Microsoft.AspNetCore.Identity.UserManager`1 [Alpha.Models.Identity.User]'的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！