在.NET9的第4个预览版里，微软带来了OpenAPI，需要引用Microsoft.AspNetCore.OpenApi，如果想生成本地的API描述文件，需要引用Microsoft.Extensions.ApiDescription.Server。
下面是项目文件：
<Project Sdk="Microsoft.NET.Sdk.Web"><PropertyGroup><TargetFramework>net9.0</TargetFramework><Nullable>enable</Nullable><ImplicitUsings>enable</ImplicitUsings></PropertyGroup><ItemGroup><PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="9.0.0-preview.4.24267.6" /><PackageReference Include="Microsoft.Extensions.ApiDescription.Server" Version="9.0.0-preview.4.24267.6"><PrivateAssets>all</PrivateAssets><IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets></PackageReference></ItemGroup><PropertyGroup><OpenApiDocumentsDirectory>$(MSBuildProjectDirectory)</OpenApiDocumentsDirectory><OpenApiGenerateDocuments>true</OpenApiGenerateDocuments></PropertyGroup></Project>
using Microsoft.AspNetCore.Http.HttpResults;using Microsoft.AspNetCore.Mvc;using Microsoft.Extensions.Logging.Configuration;using Microsoft.OpenApi.Extensions;using Microsoft.OpenApi.Interfaces;using Microsoft.OpenApi.Models;var builder = WebApplication.CreateBuilder(args);builder.Services.AddOpenApi("myapi", opt =>{opt.UseTransformer((oper, context, c) =>{oper.Info = new OpenApiInfo{Version = "v1",Title = "My API",Description = "My API Description",Contact = new OpenApiContact{Name = "My Name",Email = "aaa@aa.com"},License = new OpenApiLicense{Name = "MIT",Url = new Uri("https://opensource.org/licenses/MIT")},TermsOfService = new Uri("https://www.google.com"),};return Task.CompletedTask;});opt.ShouldInclude = (o) =>{Console.WriteLine("-----HttpMethod------" + o.HttpMethod);Console.WriteLine("-----GroupName------" + o.GroupName);Console.WriteLine("------RelativePath-----" + o.RelativePath);Console.WriteLine("------ActionDescriptor-----" + o.ActionDescriptor.DisplayName);return true;};opt.UseOperationTransformer((oper, context, c) =>{Console.WriteLine("======summary=======" + oper.Summary);oper.Summary = "gui su wei test summary";oper.Tags = new OpenApiTag[]{new OpenApiTag{Name = "tag1", Description = "tag1 description",},new OpenApiTag{Name = "tag2", Description = "tag2 description",}};return Task.CompletedTask;});});var app = builder.Build();app.MapOpenApi("/openapi/{documentName}.json");app.MapGet("/order", () =>{return new Order(){OrderNo = "20210901",Amount = 100,OrderDate = DateTime.Now};});app.MapPost("/order", (Order order) =>{return new OkResult();});app.Run();/// <summary>/// 订单/// </summary>public class Order{/// <summary>/// 订单编号/// </summary>public string OrderNo { get; set; }/// <summary>/// 订单金额/// </summary>public decimal Amount { get; set; }/// <summary>/// 订单日期/// </summary>public DateTime OrderDate { get; set; }}
下面是运行的结果：
可以通过访问http://localhost:5287/openapi/myapi.json，来查看api的json信息，同时，也可以查看生成的api.json文件，因为我们配置了api文件的生成，结果都一样，如下：
{"openapi": "3.0.1","info": {"title": "My API","description": "My API Description","termsOfService": "https://www.google.com","contact": {"name": "My Name","email": "aaa@aa.com"},"license": {"name": "MIT","url": "https://opensource.org/licenses/MIT"},"version": "v1"},"paths": {"/order": {"get": {"tags": ["tag1","tag2"],"summary": "gui su wei test summary","responses": {"200": {"description": "OK","content": {"application/json": {"schema": {"type": "object","properties": {"orderNo": {"type": "string"},"amount": {"type": "number","format": "double"},"orderDate": {"type": "string","format": "date-time"}}}}}}},"x-aspnetcore-id": "e8ba784f-bc44-4d62-9132-2e0ec46472ea"},"post": {"tags": ["tag1","tag2"],"summary": "gui su wei test summary","requestBody": {"content": {"application/json": {"schema": {"type": "object","properties": {"orderNo": {"type": "string"},"amount": {"type": "number","format": "double"},"orderDate": {"type": "string","format": "date-time"}}}}},"required": true},"responses": {"200": {"description": "OK","content": {"application/json": {"schema": {"type": "object","properties": {"statusCode": {"type": "integer","format": "int32"}}}}}}},"x-aspnetcore-id": "ddb8949d-07dc-414a-99b0-a298aab0ecb8"}}},"tags": [{"name": "OpenAPIDemo"}]}
