【NSwag】System.InvalidOperationException错误

原地址

https://github.com/RicoSuter/NSwag/issues/3584

环境

ASP.NETCore：3.1

NSwag.AspNetCore：13.13.0

引发错误

System.InvalidOperationException: Method may only be called on a Type for which Type.IsGenericParameter is true.
   at System.RuntimeType.get_GenericParameterPosition()
   at Namotion.Reflection.ContextualType.<get_Properties>b__42_0(PropertyInfo property)
   at System.Linq.Enumerable.SelectArrayIterator`2.ToArray()
   at System.Linq.Enumerable.ToArray[TSource](IEnumerable`1 source)
   at Namotion.Reflection.ContextualType.get_Properties()
   at Namotion.Reflection.ContextualTypeExtensions.GetContextualProperties(Type type)
   at NJsonSchema.Generation.JsonSchemaGenerator.ApplyAdditionalProperties[TSchemaType](TSchemaType schema, Type type, JsonSchemaResolver schemaResolver)
   at NJsonSchema.Generation.JsonSchemaGenerator.GenerateObject(JsonSchema schema, JsonTypeDescription typeDescription, JsonSchemaResolver schemaResolver)
   at NSwag.Generation.OpenApiSchemaGenerator.GenerateObject(JsonSchema schema, JsonTypeDescription typeDescription, JsonSchemaResolver schemaResolver)
   at NJsonSchema.Generation.JsonSchemaGenerator.Generate[TSchemaType](TSchemaType schema, ContextualType contextualType, JsonSchemaResolver schemaResolver)
   at NJsonSchema.Generation.JsonSchemaGenerator.Generate[TSchemaType](ContextualType contextualType, JsonSchemaResolver schemaResolver)
   at NJsonSchema.Generation.JsonSchemaGenerator.GenerateWithReferenceAndNullability[TSchemaType](ContextualType contextualType, Boolean isNullable, JsonSchemaResolver schemaResolver, Action`2 transformation)
   at NSwag.Generation.OpenApiSchemaGenerator.GenerateWithReferenceAndNullability[TSchemaType](ContextualType contextualType, Boolean isNullable, JsonSchemaResolver schemaResolver, Action`2 transformation)
   at NSwag.Generation.AspNetCore.Processors.OperationResponseProcessor.Process(OperationProcessorContext operationProcessorContext)
   at NSwag.Generation.AspNetCore.AspNetCoreOpenApiDocumentGenerator.RunOperationProcessors(OpenApiDocument document, ApiDescription apiDescription, Type controllerType, MethodInfo methodInfo, OpenApiOperationDescription operationDescription, List`1 allOperations, OpenApiDocumentGenerator swaggerGenerator, OpenApiSchemaResolver schemaResolver)
   at NSwag.Generation.AspNetCore.AspNetCoreOpenApiDocumentGenerator.AddOperationDescriptionsToDocument(OpenApiDocument document, Type controllerType, List`1 operations, OpenApiDocumentGenerator swaggerGenerator, OpenApiSchemaResolver schemaResolver)
   at NSwag.Generation.AspNetCore.AspNetCoreOpenApiDocumentGenerator.GenerateForControllers(OpenApiDocument document, IGrouping`2[] apiGroups, OpenApiSchemaResolver schemaResolver)
   at NSwag.Generation.AspNetCore.AspNetCoreOpenApiDocumentGenerator.GenerateAsync(ApiDescriptionGroupCollection apiDescriptionGroups)
   at NSwag.AspNetCore.Middlewares.OpenApiDocumentMiddleware.GenerateDocumentAsync(HttpContext context)
   at NSwag.AspNetCore.Middlewares.OpenApiDocumentMiddleware.GetDocumentAsync(HttpContext context)
   at NSwag.AspNetCore.Middlewares.OpenApiDocumentMiddleware.Invoke(HttpContext context)
   at NSwag.AspNetCore.Middlewares.SwaggerUiIndexMiddleware.Invoke(HttpContext context)
   at NSwag.AspNetCore.Middlewares.RedirectToIndexMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)

处理方案

将NSwag.AspNetCore类库升级v13.13.1

问题描述

修改前

<PackageReference Include="NSwag.AspNetCore" Version="13.13.0" />

发布后无法打开，而且本地打开也报错

(1)注释了所有的Controller下面的方法

然后Swagger页面可以打开了，只是页面没有可用的接口

 (2)结合报错提示Type，想到了MessageModel类有个泛型的T Data属性，随记更换了返回值

现在Swagger也运行正常，而且展示把Action也展示出来了

 (3)确定了是由于MessageModel泛型引发了异常，但是具体的细节就没有去看了

修改后

<PackageReference Include="NSwag.AspNetCore" Version="13.13.1" />

仍然是返回MessageModel，运行正常，所以还是NSwag类库的问题