关于.net:如何实现-ASPNET-Core-WebApi-的版本化

Web API 的版本化能够尽量保障在雷同url状况下保留一个 api 的多个版本，通常一个 webapi 会有多个client，这些client包含：app，web，html5，crawl 等等同构或者异构的平台，当 api 降级之后，往往降级前的 api 也得保留，当保护两个api的时候就是一个不小的挑战，毕竟还是存在一些 client 用户须要拜访老的api，这时候就须要将 webapi 版本化。

装置 Versioning 包

要想应用 webapi 的版本化性能，须要用 nuget 援用 Microsoft.AspNetCore.Mvc.Versioning 包，还能够通过 Visual Studio 2019 的 NuGet package manager 可视化界面装置或者通过 NuGet package manager 命令行工具输出以下命令：

dotnet add package Microsoft.AspNetCore.Mvc.Versioning

启动 API 版本化

当包胜利增加到我的项目之后，接下来就能够在 Startup.ConfigureServices 中将 ApiVersioning 注入到容器中，如下代码所示：

    public class Startup    {        public void ConfigureServices(IServiceCollection services)        {            services.AddControllers();            services.AddApiVersioning();        }    }

在调用 AddApiVersioning() 的时候记得 using Microsoft.AspNetCore.Mvc.Versioning，除了这个默认办法，还能够做一些全局配置，如下代码所示：

    public class Startup    {        public void ConfigureServices(IServiceCollection services)        {            services.AddControllers();            services.AddApiVersioning(v =>            {                v.ReportApiVersions = true;                v.AssumeDefaultVersionWhenUnspecified = true;                v.DefaultApiVersion = new ApiVersion(1, 0);            });        }    }

应用 QueryString 指定版本号

先来看一下代码，思考如下的 api。

    [ApiController]    [ApiVersion("2.0")]    [Route("api/[controller]")]    public class WeatherForecastController : ControllerBase    {        private static readonly string[] Summaries = new[]        {            "Freezing", "Bracing", "Chilly", "Cool", "Mild", "Warm", "Balmy", "Hot", "Sweltering", "Scorching"        };        [HttpGet]        public IEnumerable<WeatherForecast> Get()        {            var rng = new Random();            return Enumerable.Range(1, 5).Select(index => new WeatherForecast            {                Date = DateTime.Now.AddDays(index),                TemperatureC = rng.Next(-20, 55),                Summary = Summaries[rng.Next(Summaries.Length)]            })            .ToArray();        }    }

从代码中能够看到，我在 WeatherForecastController 上标记了该 Controller 是 v2.0 版本，接下来如何拜访呢？能够通过如下链接: http://localhost:61582/api/weatherforecast?api-version=2.0

看到这里，有些敌人就有疑难了，v2.0 的 Get 是有了，那 v1.0 的 Get 怎么拜访呢？理论开发中的做法是这样的，会用两个命名空间来示意相应的版本号，能够看如下代码：

namespace WebApplication6.Controllers.v1{    [ApiController]    [ApiVersion("1.0")]    [Route("api/[controller]")]    public class WeatherForecastController : ControllerBase    {        private static readonly string[] Summaries = new[]        {            "Freezing", "Bracing", "Chilly", "Cool", "Mild", "Warm", "Balmy", "Hot", "Sweltering", "Scorching"        };        private readonly ILogger<WeatherForecastController> _logger;        public WeatherForecastController(ILogger<WeatherForecastController> logger)        {            _logger = logger;        }        [HttpGet]        public IEnumerable<WeatherForecast> Get()        {            var rng = new Random();            return Enumerable.Range(1, 5).Select(index => new WeatherForecast            {                Date = DateTime.Now.AddDays(index),                TemperatureC = rng.Next(-20, 55),                Summary = Summaries[rng.Next(Summaries.Length)]            })            .ToArray();        }    }}namespace WebApplication6.Controllers.v2{    [ApiController]    [ApiVersion("2.0")]    [Route("api/[controller]")]    public class WeatherForecastController : ControllerBase    {        private static readonly string[] Summaries = new[]        {            "Freezing", "Bracing", "Chilly", "Cool", "Mild", "Warm", "Balmy", "Hot", "Sweltering", "Scorching"        };        private readonly ILogger<WeatherForecastController> _logger;        public WeatherForecastController(ILogger<WeatherForecastController> logger)        {            _logger = logger;        }        [HttpGet]        public IEnumerable<WeatherForecast> Get()        {            var rng = new Random();            return Enumerable.Range(1, 5).Select(index => new WeatherForecast            {                Date = DateTime.Now.AddDays(index),                TemperatureC = rng.Next(-20, 55),                Summary = Summaries[rng.Next(Summaries.Length)]            })            .ToArray();        }    }}

从下面代码能够看到 WebApplication6.Controllers.v1 示意版本 v1.0 ， WebApplication6.Controllers.v2 示意版本 v2.0，接下来顺次浏览这两个url。

应用 routes 指定版本号

很显然应用 QueryString 的形式不是很优雅也不合乎 Restful 标准，接下来看一下如何通过 Route 革新，思考上面的类，请留神我是如何在 route 中进行版本化的。

    [ApiController]    [ApiVersion("1.0")]    [Route("api/v{version:apiVersion}/[controller]")]    public class WeatherForecastController : ControllerBase    {        private static readonly string[] Summaries = new[]        {            "Freezing", "Bracing", "Chilly", "Cool", "Mild", "Warm", "Balmy", "Hot", "Sweltering", "Scorching"        };        [HttpGet]        public IEnumerable<WeatherForecast> Get()        {            var rng = new Random();            return Enumerable.Range(1, 5).Select(index => new WeatherForecast            {                Date = DateTime.Now.AddDays(index),                TemperatureC = rng.Next(-20, 55),                Summary = Summaries[rng.Next(Summaries.Length)]            })            .ToArray();        }    }

在这里，我将 [Route("api/[controller]")] 替换成了 [Route("api/v{version:apiVersion}/[controller]")]，接下来将我的项目跑起来，如下图所示：

疏忽 API 版本

在 API 版本化时，有些 API 可能只有一个版本的需要，这时候能够应用 ApiVersionNeutral 个性来漠视版本化，如下代码所示：

    [ApiVersionNeutral]    [Route("api/[controller]")]    [ApiController]    public class WeatherForecastController : ControllerBase    {        private static readonly string[] Summaries = new[]        {            "Freezing", "Bracing", "Chilly", "Cool", "Mild", "Warm", "Balmy", "Hot", "Sweltering", "Scorching"        };        [HttpGet]        public IEnumerable<WeatherForecast> Get()        {            var rng = new Random();            return Enumerable.Range(1, 5).Select(index => new WeatherForecast            {                Date = DateTime.Now.AddDays(index),                TemperatureC = rng.Next(-20, 55),                Summary = Summaries[rng.Next(Summaries.Length)]            })            .ToArray();        }    }

译文链接：https://www.infoworld.com/art...

更多高质量干货：参见我的 GitHub: csharptranslate