c# - 如果不可用，请预先附加路由

Question

我们已经实现了 ASP.NET MVC 网站的本地化版本，其 URL 结构如下:

url://{language}-{culture}/{controller}/{action}/{id}

通过这种方式，我们可以按 Google 机器人正确抓取的语言生成 URL:

1. http://localhost/en-US/Home
2. http://localhost/fr-FR/Home

翻译是在两个地方实现的。首先我们用这个修改了MVC的默认路由:

routes.MapRoute(
    name: "Default",
    url: "{language}-{culture}/{controller}/{action}/{id}",
    defaults: new
    {
        controller = "Home", 
        action = "Index", 
        id = UrlParameter.Optional,
        language = "en",
        culture = "US"
    }
);

然后我们创建了一个操作过滤器，它切换到 URL 中可用的当前语言，如果不可用则切换到默认语言:

   public class LocalizationAttribute : ActionFilterAttribute
    {        public override void OnActionExecuting(ActionExecutingContext filterContext)
        {

            string language = (string)filterContext.RouteData.Values["language"] ?? "en";
            string culture = (string)filterContext.RouteData.Values["culture"] ?? "US";

            Thread.CurrentThread.CurrentCulture = CultureInfo.GetCultureInfo(string.Format("{0}-{1}", language, culture));
            Thread.CurrentThread.CurrentUICulture = CultureInfo.GetCultureInfo(string.Format("{0}-{1}", language, culture));

        }
    }
}

如果用户输入 http://localhost/Whatever 就会出现问题. ASP.NET MVC 返回“找不到路由”。如果用户忘记传递语言的默认参数，我该如何传递？我虽然通过将默认值设置到路由配置中就足够了，但它不起作用

Answer 1

您只需要另一条路线来处理没有第一段的情况。

routes.MapRoute(
    name: "Default-Localized",
    url: "{language}-{culture}/{controller}/{action}/{id}",
    defaults: new
    {
        controller = "Home", 
        action = "Index", 
        id = UrlParameter.Optional
    }
);

routes.MapRoute(
    name: "Default",
    url: "{controller}/{action}/{id}",
    defaults: new
    {
        language = "en",
        culture = "US",
        controller = "Home", 
        action = "Index", 
        id = UrlParameter.Optional
    }
);

匹配 URL 模式和构建路由值集合(基于默认值或可以覆盖它们的占位符)是 Route 类处理的 2 个不同步骤。除非 URL 模式首先匹配，否则不会填充路由值。

请注意，如果您使用操作过滤器来设置当前线程的语言环境，localization won't be available inside of the model binder .一种解决方法是使用 IAuthorizationFilter 而不是 ActionFilterAttribute。

using System.Globalization;
using System.Threading;
using System.Web.Mvc;

public class LocalizationFilter : IAuthorizationFilter
{
    public void OnAuthorization(AuthorizationContext filterContext)
    {
        var values = filterContext.RouteData.Values;

        string language = (string)values["language"] ?? "en";
        string culture = (string)values["culture"] ?? "US";

        CultureInfo ci= CultureInfo.GetCultureInfo(string.Format("{0}-{1}", language, culture));

        Thread.CurrentThread.CurrentCulture = ci;
        Thread.CurrentThread.CurrentUICulture = ci;
    }
}

然后将其添加为全局过滤器。

public class FilterConfig
{
    public static void RegisterGlobalFilters(GlobalFilterCollection filters)
    {
        filters.Add(new LocalizationFilter());
        filters.Add(new HandleErrorAttribute());
    }
}