无法使用服务容器中的服务和默认值实例化类型 'MyProject.Response' 的构造函数
No constructor for type 'MyProject.Response' can be instantiated using services from the service container and default values
我正在使用 asp.net 核心 3.1 项目模板开发网站 API。没有编译错误。
这是我的代码详情：
Program.cs
public class Program
{
public static void Main(string[] args)
{
// Use the W3C Trace Context format to propagate distributed trace identifiers.
// See https://devblogs.microsoft.com/aspnet/improvements-in-net-core-3-0-for-troubleshooting-and-monitoring-distributed-apps/
Activity.DefaultIdFormat = ActivityIdFormat.W3C;
CreateHostBuilder(args).Build().Run();
}
public static IHostBuilder CreateHostBuilder(string[] args) =>
Host.CreateDefaultBuilder(args)
.ConfigureWebHostDefaults(webBuilder =>
{
webBuilder.UseStartup<Startup>();
});
}
Startup.cs
public class Startup
{
private readonly IConfiguration configuration;
private readonly IWebHostEnvironment webHostEnvironment;
/// <summary>
/// Initializes a new instance of the <see cref = "Startup"/> class.
/// </summary>
/// <param name = "configuration">The application configuration, where key value pair settings are stored. See
/// http://docs.asp.net/en/latest/fundamentals/configuration.html</param>
/// <param name = "webHostEnvironment">The environment the application is running under. This can be Development,
/// Staging or Production by default. See http://docs.asp.net/en/latest/fundamentals/environments.html</param>
public Startup(IConfiguration configuration, IWebHostEnvironment webHostEnvironment)
{
this.configuration = configuration;
this.webHostEnvironment = webHostEnvironment;
}
/// <summary>
/// Configures the services to add to the ASP.NET Core Injection of Control (IoC) container. This method gets
/// called by the ASP.NET runtime. See
/// http://blogs.msdn.com/b/webdev/archive/2014/06/17/dependency-injection-in-asp-net-vnext.aspx
/// </summary>
public virtual void ConfigureServices(IServiceCollection services) =>
services
.AddCosmosDBConfiguration(configuration)
.AddAutoMapperConfiguration()
.AddCustomResponseCompression(configuration)
.AddCustomCors()
.AddCustomOptions(configuration)
.AddHttpContextAccessor()
.AddCustomRouting()
.AddCustomStrictTransportSecurity()
.AddCustomHealthChecks()
.AddServerTiming()
.AddControllers()
.AddCustomJsonOptions(webHostEnvironment)
.AddCustomMvcOptions(configuration)
.Services
.AddCustomGraphQL(configuration, webHostEnvironment)
.AddGraphQLResolvers()
.AddGraphQLResponse()
.AddProjectRepositories()
.AddProjectSchemas();
/// <summary>
/// Configures the application and HTTP request pipeline. Configure is called after ConfigureServices is
/// called by the ASP.NET runtime.
/// </summary>
public virtual void Configure(IApplicationBuilder application) =>
application
.UseIf(
this.webHostEnvironment.IsDevelopment(),
x => x.UseServerTiming())
.UseForwardedHeaders()
.UseResponseCompression()
.UseFetchLocaleMiddleware()
.UseIf(
!this.webHostEnvironment.IsDevelopment(),
x => x.UseHsts())
.UseIf(
this.webHostEnvironment.IsDevelopment(),
x => x.UseDeveloperExceptionPage())
.UseRouting()
.UseCors(CorsPolicyName.AllowAny)
.UseEndpoints(
builder =>
{
builder
.MapHealthChecks("/status")
.RequireCors(CorsPolicyName.AllowAny);
builder
.MapHealthChecks("/status/self", new HealthCheckOptions() { Predicate = _ => false })
.RequireCors(CorsPolicyName.AllowAny);
})
.UseWebSockets()
// Use the GraphQL subscriptions in the specified schema and make them available at /graphql.
.UseGraphQLWebSockets<MainSchema>()
// Use the specified GraphQL schema and make them available at /graphql.
.UseGraphQL<MainSchema>()
.UseIf(
this.webHostEnvironment.IsDevelopment(),
x => x
// Add the GraphQL Playground UI to try out the GraphQL API at /.
.UseGraphQLPlayground(new GraphQLPlaygroundOptions() { Path = "/" })
// Add the GraphQL Voyager UI to let you navigate your GraphQL API as a spider graph at /voyager.
.UseGraphQLVoyager(new GraphQLVoyagerOptions() { Path = "/voyager" }));
}
Response.cs
public class Response
{
public object Data { get; set; }
public string StatusCode { get; set; }
public string ErrorMessage { get; set; }
public Response(object data)
{
StatusCode = "Success";
Data = data;
}
public Response(string statusCode, string errorMessage)
{
StatusCode = statusCode;
ErrorMessage = errorMessage;
}
}
Startup.cs ConfigureServices 中提到的所有依赖项都可用。在验证 APIs 时，我收到 运行 时间错误，如下所述：
No constructor for type 'MyProject.Response' can be instantiated using services from the service container and default values.
响应 class 所需的依赖设置如下所述：
ProjectServiceCollectionExtensions.cs
namespace MyProject
{
public static class ProjectServiceCollectionExtensions
{
public static IServiceCollection AddGraphQLResponse(this IServiceCollection services) => services.AddScoped<Response>();
}
}
Resolver.cs
public class Resolver
{
public Response Response(object data)
{
return new Response(data);
}
public Response Error(GraphQLError error)
{
return new Response(error.StatusCode, error.ErrorMessage);
}
public Response AccessDeniedError()
{
var error = new AccessDeniedError();
return new Response(error.StatusCode, error.ErrorMessage);
}
public Response NotFoundError(string id)
{
var error = new NotFoundError(id);
return new Response(error.StatusCode, error.ErrorMessage);
}
}
国家Resolver.cs
using Author.Core.Framework.Utilities;
using Author.Query.New.API.GraphQL.Types;
using Author.Query.Persistence.DTO;
using Author.Query.Persistence.Interfaces;
using GraphQL.DataLoader;
using GraphQL.Types;
using Microsoft.AspNetCore.Http;
using System;
namespace MyProject.GraphQL.Resolvers
{
public class CountriesResolver : Resolver, ICountriesResolver
{
private readonly ICountryService _countryService;
private readonly IHttpContextAccessor _accessor;
private readonly IUtilityService _utilityService;
private readonly IDataLoaderContextAccessor _dataLoaderContextAccessor;
public CountriesResolver(ICountryService countryService, IHttpContextAccessor accessor, IUtilityService utilityService, IDataLoaderContextAccessor dataLoaderContextAccessor)
{
_countryService = countryService ?? throw new ArgumentNullException(nameof(countryService));
_accessor = accessor;
_utilityService = utilityService ?? throw new ArgumentNullException(nameof(utilityService));
_dataLoaderContextAccessor = dataLoaderContextAccessor;
}
public void Resolve(GraphQLQuery graphQLQuery)
{
var language = _accessor.HttpContext.Items["language"] as LanguageDTO;
graphQLQuery.FieldAsync<ResponseGraphType<CountryResultType>>("countriesresponse", resolve: async context =>
{
if (language != null)
{
var loader = _dataLoaderContextAccessor.Context.GetOrAddLoader("GetAllCountries", () => _countryService.GetAllCountriesAsync(language));
var list = await context.TryAsyncResolve(async c => await loader.LoadAsync());
return Response(list);
}
return null;
}
, description: "All Countries data");
graphQLQuery.FieldAsync<ResponseGraphType<CountryType>>("country", arguments: new QueryArguments(new QueryArgument<NonNullGraphType<IntGraphType>>{Name = "countryId", Description = "id of the country"}), resolve: async context =>
{
var countryId = context.GetArgument<int>("countryId");
if (language != null && countryId > 0)
{
var loader = _dataLoaderContextAccessor.Context.GetOrAddLoader("GetCountry", () => _countryService.GetCountryAsync(language, countryId));
var countryDetails = await context.TryAsyncResolve(async c => await loader.LoadAsync());
return Response(countryDetails);
}
return null;
}
);
}
}
}
谁能提供指导帮助我解决这个问题
根据 Resolver 使用 Response 的方式，我认为 Response 不需要添加到 DI/IoC 容器中，因为 Resolver本质上是一个 Response 工厂
如果 Response 没有显式地注入到任何地方，那么容器不需要知道它。无需将其添加到开头的容器中。
移除
//...
.AddGraphQLResponse() //<--SHOULD BE REMOVED
//...
来自 Startup.ConfigureServices
的扩展
我正在使用 asp.net 核心 3.1 项目模板开发网站 API。没有编译错误。
这是我的代码详情：
Program.cs
public class Program
{
public static void Main(string[] args)
{
// Use the W3C Trace Context format to propagate distributed trace identifiers.
// See https://devblogs.microsoft.com/aspnet/improvements-in-net-core-3-0-for-troubleshooting-and-monitoring-distributed-apps/
Activity.DefaultIdFormat = ActivityIdFormat.W3C;
CreateHostBuilder(args).Build().Run();
}
public static IHostBuilder CreateHostBuilder(string[] args) =>
Host.CreateDefaultBuilder(args)
.ConfigureWebHostDefaults(webBuilder =>
{
webBuilder.UseStartup<Startup>();
});
}
Startup.cs
public class Startup
{
private readonly IConfiguration configuration;
private readonly IWebHostEnvironment webHostEnvironment;
/// <summary>
/// Initializes a new instance of the <see cref = "Startup"/> class.
/// </summary>
/// <param name = "configuration">The application configuration, where key value pair settings are stored. See
/// http://docs.asp.net/en/latest/fundamentals/configuration.html</param>
/// <param name = "webHostEnvironment">The environment the application is running under. This can be Development,
/// Staging or Production by default. See http://docs.asp.net/en/latest/fundamentals/environments.html</param>
public Startup(IConfiguration configuration, IWebHostEnvironment webHostEnvironment)
{
this.configuration = configuration;
this.webHostEnvironment = webHostEnvironment;
}
/// <summary>
/// Configures the services to add to the ASP.NET Core Injection of Control (IoC) container. This method gets
/// called by the ASP.NET runtime. See
/// http://blogs.msdn.com/b/webdev/archive/2014/06/17/dependency-injection-in-asp-net-vnext.aspx
/// </summary>
public virtual void ConfigureServices(IServiceCollection services) =>
services
.AddCosmosDBConfiguration(configuration)
.AddAutoMapperConfiguration()
.AddCustomResponseCompression(configuration)
.AddCustomCors()
.AddCustomOptions(configuration)
.AddHttpContextAccessor()
.AddCustomRouting()
.AddCustomStrictTransportSecurity()
.AddCustomHealthChecks()
.AddServerTiming()
.AddControllers()
.AddCustomJsonOptions(webHostEnvironment)
.AddCustomMvcOptions(configuration)
.Services
.AddCustomGraphQL(configuration, webHostEnvironment)
.AddGraphQLResolvers()
.AddGraphQLResponse()
.AddProjectRepositories()
.AddProjectSchemas();
/// <summary>
/// Configures the application and HTTP request pipeline. Configure is called after ConfigureServices is
/// called by the ASP.NET runtime.
/// </summary>
public virtual void Configure(IApplicationBuilder application) =>
application
.UseIf(
this.webHostEnvironment.IsDevelopment(),
x => x.UseServerTiming())
.UseForwardedHeaders()
.UseResponseCompression()
.UseFetchLocaleMiddleware()
.UseIf(
!this.webHostEnvironment.IsDevelopment(),
x => x.UseHsts())
.UseIf(
this.webHostEnvironment.IsDevelopment(),
x => x.UseDeveloperExceptionPage())
.UseRouting()
.UseCors(CorsPolicyName.AllowAny)
.UseEndpoints(
builder =>
{
builder
.MapHealthChecks("/status")
.RequireCors(CorsPolicyName.AllowAny);
builder
.MapHealthChecks("/status/self", new HealthCheckOptions() { Predicate = _ => false })
.RequireCors(CorsPolicyName.AllowAny);
})
.UseWebSockets()
// Use the GraphQL subscriptions in the specified schema and make them available at /graphql.
.UseGraphQLWebSockets<MainSchema>()
// Use the specified GraphQL schema and make them available at /graphql.
.UseGraphQL<MainSchema>()
.UseIf(
this.webHostEnvironment.IsDevelopment(),
x => x
// Add the GraphQL Playground UI to try out the GraphQL API at /.
.UseGraphQLPlayground(new GraphQLPlaygroundOptions() { Path = "/" })
// Add the GraphQL Voyager UI to let you navigate your GraphQL API as a spider graph at /voyager.
.UseGraphQLVoyager(new GraphQLVoyagerOptions() { Path = "/voyager" }));
}
Response.cs
public class Response
{
public object Data { get; set; }
public string StatusCode { get; set; }
public string ErrorMessage { get; set; }
public Response(object data)
{
StatusCode = "Success";
Data = data;
}
public Response(string statusCode, string errorMessage)
{
StatusCode = statusCode;
ErrorMessage = errorMessage;
}
}
Startup.cs ConfigureServices 中提到的所有依赖项都可用。在验证 APIs 时，我收到 运行 时间错误，如下所述：
No constructor for type 'MyProject.Response' can be instantiated using services from the service container and default values.
响应 class 所需的依赖设置如下所述：
ProjectServiceCollectionExtensions.cs
namespace MyProject
{
public static class ProjectServiceCollectionExtensions
{
public static IServiceCollection AddGraphQLResponse(this IServiceCollection services) => services.AddScoped<Response>();
}
}
Resolver.cs
public class Resolver
{
public Response Response(object data)
{
return new Response(data);
}
public Response Error(GraphQLError error)
{
return new Response(error.StatusCode, error.ErrorMessage);
}
public Response AccessDeniedError()
{
var error = new AccessDeniedError();
return new Response(error.StatusCode, error.ErrorMessage);
}
public Response NotFoundError(string id)
{
var error = new NotFoundError(id);
return new Response(error.StatusCode, error.ErrorMessage);
}
}
国家Resolver.cs
using Author.Core.Framework.Utilities;
using Author.Query.New.API.GraphQL.Types;
using Author.Query.Persistence.DTO;
using Author.Query.Persistence.Interfaces;
using GraphQL.DataLoader;
using GraphQL.Types;
using Microsoft.AspNetCore.Http;
using System;
namespace MyProject.GraphQL.Resolvers
{
public class CountriesResolver : Resolver, ICountriesResolver
{
private readonly ICountryService _countryService;
private readonly IHttpContextAccessor _accessor;
private readonly IUtilityService _utilityService;
private readonly IDataLoaderContextAccessor _dataLoaderContextAccessor;
public CountriesResolver(ICountryService countryService, IHttpContextAccessor accessor, IUtilityService utilityService, IDataLoaderContextAccessor dataLoaderContextAccessor)
{
_countryService = countryService ?? throw new ArgumentNullException(nameof(countryService));
_accessor = accessor;
_utilityService = utilityService ?? throw new ArgumentNullException(nameof(utilityService));
_dataLoaderContextAccessor = dataLoaderContextAccessor;
}
public void Resolve(GraphQLQuery graphQLQuery)
{
var language = _accessor.HttpContext.Items["language"] as LanguageDTO;
graphQLQuery.FieldAsync<ResponseGraphType<CountryResultType>>("countriesresponse", resolve: async context =>
{
if (language != null)
{
var loader = _dataLoaderContextAccessor.Context.GetOrAddLoader("GetAllCountries", () => _countryService.GetAllCountriesAsync(language));
var list = await context.TryAsyncResolve(async c => await loader.LoadAsync());
return Response(list);
}
return null;
}
, description: "All Countries data");
graphQLQuery.FieldAsync<ResponseGraphType<CountryType>>("country", arguments: new QueryArguments(new QueryArgument<NonNullGraphType<IntGraphType>>{Name = "countryId", Description = "id of the country"}), resolve: async context =>
{
var countryId = context.GetArgument<int>("countryId");
if (language != null && countryId > 0)
{
var loader = _dataLoaderContextAccessor.Context.GetOrAddLoader("GetCountry", () => _countryService.GetCountryAsync(language, countryId));
var countryDetails = await context.TryAsyncResolve(async c => await loader.LoadAsync());
return Response(countryDetails);
}
return null;
}
);
}
}
}
谁能提供指导帮助我解决这个问题
根据 Resolver 使用 Response 的方式，我认为 Response 不需要添加到 DI/IoC 容器中，因为 Resolver本质上是一个 Response 工厂
如果 Response 没有显式地注入到任何地方，那么容器不需要知道它。无需将其添加到开头的容器中。
移除
//...
.AddGraphQLResponse() //<--SHOULD BE REMOVED
//...
来自 Startup.ConfigureServices