ASP.NET Core 3.1 web API（版本控制）和 Swagger UI 由于 MvcJsonOptions 一旦发布到 Azure 而失败

Question

我最近将 ASP.NET Core 2.2 Web API 项目迁移到 ASP.NET Core 3.1 Preview 3。我使用基于 URL 的 API 版本控制和 Swagger UI 3.0 (Swashbuckle.AspNetCore 5.0.0-rc4)。一旦网络 API 在 Azure 上发布，我就会遇到以下错误（我不确定 Swagger UI 是否与它有任何关系但是......）

System.InvalidOperationException: 比较数组中的两个元素失败。 ---> System.TypeLoadException: 无法从程序集 'Microsoft.AspNetCore.Mvc.Formatters.Json,

加载类型 'Microsoft.AspNetCore.Mvc.MvcJsonOptions'

参考 Git Hub 中的类似问题，我的理解是问题已通过预览版 3 修复，并且确实在安装 SDK 3.1.100-preview3 之后，我知道在我的本地开发机器上没有看到这个问题。

本地开发机器（一切正常...）

发布到 Azure Web 服务

由于尚不支持该框架，因此我将其发布为独立的 Web api 应用程序。发布成功，但在运行时出现以下问题...如何解决此问题？

System.InvalidOperationException: Failed to compare two elements in the array.
 ---> System.TypeLoadException: Could not load type 'Microsoft.AspNetCore.Mvc.MvcJsonOptions' from assembly 'Microsoft.AspNetCore.Mvc.Formatters.Json, Version=3.1.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'.
   at System.Signature.GetSignature(Void* pCorSig, Int32 cCorSig, RuntimeFieldHandleInternal fieldHandle, IRuntimeMethodInfo methodHandle, RuntimeType declaringType)
   at System.Reflection.RuntimeConstructorInfo.get_Signature()
   at System.Reflection.RuntimeConstructorInfo.GetParametersNoCopy()
   at System.Reflection.RuntimeConstructorInfo.GetParameters()
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.<>c.<CreateConstructorCallSite>b__16_1(ConstructorInfo a, ConstructorInfo b)
   at System.Collections.Generic.ArraySortHelper`1.SwapIfGreater(T[] keys, Comparison`1 comparer, Int32 a, Int32 b)
   at System.Collections.Generic.ArraySortHelper`1.IntroSort(T[] keys, Int32 lo, Int32 hi, Int32 depthLimit, Comparison`1 comparer)
   at System.Collections.Generic.ArraySortHelper`1.IntrospectiveSort(T[] keys, Int32 left, Int32 length, Comparison`1 comparer)
   at System.Collections.Generic.ArraySortHelper`1.Sort(T[] keys, Int32 index, Int32 length, Comparison`1 comparer)
   --- End of inner exception stack trace ---
   at System.Collections.Generic.ArraySortHelper`1.Sort(T[] keys, Int32 index, Int32 length, Comparison`1 comparer)
   at System.Array.Sort[T](T[] array, Comparison`1 comparison)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.CreateConstructorCallSite(ResultCache lifetime, Type serviceType, Type implementationType, CallSiteChain callSiteChain)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.TryCreateExact(ServiceDescriptor descriptor, Type serviceType, CallSiteChain callSiteChain, Int32 slot)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.TryCreateExact(Type serviceType, CallSiteChain callSiteChain)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.CreateCallSite(Type serviceType, CallSiteChain callSiteChain)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.<>c__DisplayClass7_0.<GetCallSite>b__0(Type type)
   at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.GetCallSite(Type serviceType, CallSiteChain callSiteChain)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.CreateArgumentCallSites(Type serviceType, Type implementationType, CallSiteChain callSiteChain, ParameterInfo[] parameters, Boolean throwIfCallSiteNotFound)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.CreateConstructorCallSite(ResultCache lifetime, Type serviceType, Type implementationType, CallSiteChain callSiteChain)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.TryCreateExact(ServiceDescriptor descriptor, Type serviceType, CallSiteChain callSiteChain, Int32 slot)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.TryCreateExact(Type serviceType, CallSiteChain callSiteChain)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.CreateCallSite(Type serviceType, CallSiteChain callSiteChain)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.<>c__DisplayClass7_0.<GetCallSite>b__0(Type type)
   at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.GetCallSite(Type serviceType, CallSiteChain callSiteChain)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.CreateArgumentCallSites(Type serviceType, Type implementationType, CallSiteChain callSiteChain, ParameterInfo[] parameters, Boolean throwIfCallSiteNotFound)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.CreateConstructorCallSite(ResultCache lifetime, Type serviceType, Type implementationType, CallSiteChain callSiteChain)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.TryCreateExact(ServiceDescriptor descriptor, Type serviceType, CallSiteChain callSiteChain, Int32 slot)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.TryCreateExact(Type serviceType, CallSiteChain callSiteChain)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.CreateCallSite(Type serviceType, CallSiteChain callSiteChain)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.<>c__DisplayClass7_0.<GetCallSite>b__0(Type type)
   at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.GetCallSite(Type serviceType, CallSiteChain callSiteChain)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngine.CreateServiceAccessor(Type serviceType)
   at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngine.GetService(Type serviceType, ServiceProviderEngineScope serviceProviderEngineScope)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngineScope.GetService(Type serviceType)
   at Microsoft.AspNetCore.Builder.UseMiddlewareExtensions.GetService(IServiceProvider sp, Type type, Type middleware)
   at lambda_method(Closure , Object , HttpContext , IServiceProvider )
   at Microsoft.AspNetCore.Builder.UseMiddlewareExtensions.<>c__DisplayClass4_1.<UseMiddleware>b__2(HttpContext context)

Answer 1

对于 ASP.NET Core 3.0（和 3.1），请确保至少针对 Swashbuckle.AspNetCore 版本 5.0（不是 RC 版本）。这应该可以解决该特定问题。

您遇到此问题的原因是 Swagger 以前依赖于 MvcJsonOptions，它是 ASP.NET 核心框架的一部分。 Swagger 加载并尝试查找 class，但它不存在。但是现在由于 ASP.NET 核心框架使用 System.Text.Json 而不是 Newtonsoft.Json 导致编译错误。

关于同一主题，我建议您 read this here，这说明了如果您仍想继续使用，如何选择加入 Newtonsoft.Json。

总的来说，Swagger 的实现有一些重大变化。这是关于 what is breaking in 4.0 and what is breaking in 5.0.

的很好的文档

ASP.NET Core 3.1 web API（版本控制）和 Swagger UI 由于 MvcJsonOptions 一旦发布到 Azure 而失败

ASP.NET Core 3.1 web API (versioning) and Swagger UI fails due to MvcJsonOptions once published to Azure

azure

asp.net-core

asp.net-core-mvc

swagger-ui

asp.net-core-3.0