使用 .NET Core 3.0 添加 swagger 时出现异常

Question

我正在尝试将 swagger 集成到一个ASP NET Core 3.0项目中，它在ConfigureServices方法中抛出异常：

我正在使用Swashbuckle.AspNetCore4.0.1。

我也检查了这个问题，还有这个

public void ConfigureServices(IServiceCollection services)
        {


            services.AddSwaggerGen(c =>
            {
                c.SwaggerDoc("v1", new Swashbuckle.AspNetCore.Swagger.Info
                {
                    Version = "v1",
                    Title = " API",
                    Description="API for the  Server",
                });

            });
        }

例外

System.AggregateException
  HResult=0x80131500
  Message=Some services are not able to be constructed (Error while validating the service descriptor 'ServiceType: Swashbuckle.AspNetCore.Swagger.ISwaggerProvider Lifetime: Transient ImplementationType: Swashbuckle.AspNetCore.SwaggerGen.SwaggerGenerator': Failed to compare two elements in the array.) (Error while validating the service descriptor 'ServiceType: Swashbuckle.AspNetCore.SwaggerGen.ISchemaRegistryFactory Lifetime: Transient ImplementationType: Swashbuckle.AspNetCore.SwaggerGen.SchemaRegistryFactory': Failed to compare two elements in the array.)
  Source=Microsoft.Extensions.DependencyInjection
  StackTrace:
   at Microsoft.Extensions.DependencyInjection.ServiceProvider..ctor(IEnumerable`1 serviceDescriptors, ServiceProviderOptions options)
   at Microsoft.Extensions.DependencyInjection.ServiceCollectionContainerBuilderExtensions.BuildServiceProvider(IServiceCollection services, ServiceProviderOptions options)
   at Microsoft.Extensions.DependencyInjection.DefaultServiceProviderFactory.CreateServiceProvider(IServiceCollection containerBuilder)
   at Microsoft.Extensions.Hosting.Internal.ServiceFactoryAdapter`1.CreateServiceProvider(Object containerBuilder)
   at Microsoft.Extensions.Hosting.HostBuilder.CreateServiceProvider()
   at Microsoft.Extensions.Hosting.HostBuilder.Build()
   at SXS.Server.Program.Main(String[] args) in C:\Work\SXS\SXS\Core\Server\SXS.Server\Program.cs:line 32

Inner Exception 1:
InvalidOperationException: Error while validating the service descriptor 'ServiceType: Swashbuckle.AspNetCore.Swagger.ISwaggerProvider Lifetime: Transient ImplementationType: Swashbuckle.AspNetCore.SwaggerGen.SwaggerGenerator': Failed to compare two elements in the array.

Inner Exception 2:
InvalidOperationException: Failed to compare two elements in the array.

Inner Exception 3:
TypeLoadException: Could not load type 'Microsoft.AspNetCore.Mvc.MvcJsonOptions' from assembly 'Microsoft.AspNetCore.Mvc.Formatters.Json, Version=3.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'.

PS 我遵循了本指南，唯一的区别是，虽然他使用了一个OpenApiInfo对象，但我没有可用的重载，因此我使用的是Info.

Answer 1

我使用 .Net Core 3.1.2 和 Swagger 5.4.1 遇到了这个问题。

原来我忘了添加services.AddControllers();到我的Startup::ConfigureServices方法中。

我只是添加了 Razor Pages。

Answer 2

我刚刚在 docs.microsoft.com 上阅读了 Swashbuckle 和 ASP.NET Core的入门，没有任何问题。

文档说明您需要使用最新的 Swashbuckle.AspNetCore 预览版，5.0.0-rc4