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 ASP NET Core 3.0 项目中，它在 ConfigureServices 方法中抛出异常：

我正在使用 Swashbuckle.AspNetCore 4.0.1.

这个我也查过了 and also this

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",
                });

            });
        }

异常

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'.

P.S 我遵循了这个 guide 唯一的区别是当他使用 OpenApiInfo 对象时我没有那个过载可用，因此我正在使用 Info.

Answer 1

我刚刚在 docs.microsoft.com 完成了 Get started with Swashbuckle and ASP.NET Core，没遇到任何问题。

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

Answer 2

这通常是由于使用了错误的 swagger 包，因此信息 api 使用了 Swashbuckle.AspNetCore.Swagger.Info，这导致了问题。

如果您使用最新的 Swashbuckle.AspNetCore、5.0.0-rc4m 包，那么它将从新的 Microsoft.OpenApi.Models 中获取 OpenApiInfo，然后它就会工作。

编码愉快！

Answer 3

我试过了，效果很好：

services.AddSwaggerGen(c =>
        {
            c.SwaggerDoc("v1", new OpenApiInfo
            {
                Version = "v1",
                Title = "My API",
                Description = "My API description for blah blah"
            });
        });

顺便说一句，我正在使用 .Net Core 2.1

Answer 4

我在使用 .Net Core 3.1.2 和 Swagger 5.4.1 时遇到了这个问题。

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

我只是添加了 Razor Pages。

使用 .NET Core 3.0 添加 swagger 时出现异常

Exception when adding swagger with .NET Core 3.0

swagger

swashbuckle

asp.net-core-3.0