ASP.NET Core WebAPI实现本地化(单资源文件)

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在Startup ConfigureServices 注册本地化所需要的服务AddLocalization和 Configure<RequestLocalizationOptions>

 public void ConfigureServices(IServiceCollection services)
  {
   services.AddLocalization();
   services.Configure<RequestLocalizationOptions>(options =>
   {
    var supportedCultures = new List<CultureInfo>
    {
     new CultureInfo("en-us"),
     new CultureInfo("zh-cn")
    };

    options.DefaultRequestCulture = new RequestCulture(culture: "en-us", uiCulture: "en-us");
    options.SupportedCultures = supportedCultures;
    options.SupportedUICultures = supportedCultures;
    options.RequestCultureProviders = new IRequestCultureProvider[] { new RouteDataRequestCultureProvider { IndexOfCulture = 1, IndexofUiCulture = 1 } };
   });
   services.Configure<RouteOptions>(options =>
   {
    options.ConstraintMap.Add("culture", typeof(LanguageRouteConstraint));
   });
   services.AddControllers();
  }

在Startup.cs类的Configure 方法中添加请求本地化中间件。

 var localizeOptions = app.ApplicationServices.GetService<IOptions<RequestLocalizationOptions>>();
   app.UseRequestLocalization(localizeOptions.Value);

RequestCultureProvider 它使用简单的委托来确定当前的本地化区域性，当然我们还可以通过RequestCultureProvider自定义源的请求区域信息比如说配置文件或者数据库都是可以的.或者说我们可以选用默认的一些方式让我们去获取到当前区域.

ASP.NET Core 本地化默认向我们提供了四个方式，可用于确定正在执行的请求的当前区域性：

QueryStringRequestCultureProvider
CookieRequestCultureProvider
AcceptLanguageHeaderRequestCultureProvider
CustomRequestCultureProvider

如下所示我将通过路由的方式,去确定当前区域

public class RouteDataRequestCultureProvider : RequestCultureProvider
 {
  public int IndexOfCulture;
  public int IndexofUiCulture;

  public override Task<ProviderCultureResult> DetermineProviderCultureResult(HttpContext httpContext)
  {
   if (httpContext == null)
    throw new ArgumentNullException(nameof(httpContext));
   string uiCulture;

   string culture = uiCulture = httpContext.Request.Path.Value.Split('/')[IndexOfCulture];

   var providerResultCulture = new ProviderCultureResult(culture, uiCulture);

   return Task.FromResult(providerResultCulture);
  }
 }

通过如下代码片段实现IRouteConstraint对路由做相应的约束

 public class LanguageRouteConstraint : IRouteConstraint
 {
  public bool Match(HttpContext httpContext, IRouter route, string routeKey, RouteValueDictionary values, RouteDirection routeDirection)
  {

   if (!values.ContainsKey("culture"))
    return false;

   var culture = values["culture"].ToString();
   return culture == "en-us" || culture == "zh-cn";
  }
 }

添加区域资源文件

注入IStringLocalizer<T>，StringLocalizer将通过传递的共享资源(T)的值映射到资源文件,然后将本地化根据字符串的名称从资源文件返回响应的值

 [Route("{culture:culture}/[controller]")]
 [ApiController]
 public class HomeController : ControllerBase
 {
  private readonly IStringLocalizer<Resource> localizer;
  public HomeController(IStringLocalizer<Resource> localizer)
  {
   this.localizer = localizer;
  }
  public string Get()
  {
   return localizer["Home"];
  }
 }

如下图所示