匹配路径相对于路径

Question

我希望任何以 /templates/{filename} 结尾的 URL 使用路由属性映射到特定控制器，例如：

public class TemplateController : Controller
{
    [Route("templates/{templateFilename}")]
    public ActionResult Index(string templateFilename)
    {
        ....
    }

}

这可行，但引用此路线的链接是相对的，所以

• http://localhost/templates/t1 -- 有效
• http://localhost/foo/bar/templates/t2 -- 中断 (404)

我需要类似的东西：

[Route("*/templates/{templateFilename}")]

Answer 1

你不能用属性路由来完成这样的事情。只能通过实现IRouteConstraint 或子类化RouteBase 来进行高级路由匹配。

在这种情况下，继承RouteBase 更简单。这是一个例子：

public class EndsWithRoute : RouteBase
{
    private readonly Regex urlPattern;
    private readonly string controllerName;
    private readonly string actionName;
    private readonly string prefixName;
    private readonly string parameterName;

    public EndsWithRoute(string controllerName, string actionName, string prefixName, string parameterName)
    {
        if (string.IsNullOrWhiteSpace(controllerName))
            throw new ArgumentException($"'{nameof(controllerName)}' is required.");
        if (string.IsNullOrWhiteSpace(actionName))
            throw new ArgumentException($"'{nameof(actionName)}' is required.");
        if (string.IsNullOrWhiteSpace(prefixName))
            throw new ArgumentException($"'{nameof(prefixName)}' is required.");
        if (string.IsNullOrWhiteSpace(parameterName))
            throw new ArgumentException($"'{nameof(parameterName)}' is required.");

        this.controllerName = controllerName;
        this.actionName = actionName;
        this.prefixName = prefixName;
        this.parameterName = parameterName;
        this.urlPattern = new Regex($"{prefixName}/[^/]+/?$", RegexOptions.Compiled | RegexOptions.IgnoreCase);
    }

    public override RouteData GetRouteData(HttpContextBase httpContext)
    {
        var path = httpContext.Request.Path;

        // Check if the URL pattern matches
        if (!urlPattern.IsMatch(path, 1))
            return null;

        // Get the value of the last segment
        var param = path.Split('/').Last();

        var routeData = new RouteData(this, new MvcRouteHandler());

        //Invoke MVC controller/action
        routeData.Values["controller"] = controllerName;
        routeData.Values["action"] = actionName;
        // Putting the myParam value into route values makes it
        // available to the model binder and to action method parameters.
        routeData.Values[parameterName] = param;

        return routeData;
    }

    public override VirtualPathData GetVirtualPath(RequestContext requestContext, RouteValueDictionary values)
    {
        object controllerObj;
        object actionObj;
        object parameterObj;

        values.TryGetValue("controller", out controllerObj);
        values.TryGetValue("action", out actionObj);
        values.TryGetValue(parameterName, out parameterObj);

        if (controllerName.Equals(controllerObj.ToString(), StringComparison.OrdinalIgnoreCase) 
            && actionName.Equals(actionObj.ToString(), StringComparison.OrdinalIgnoreCase)
            && !string.IsNullOrEmpty(parameterObj.ToString()))
        {
            return new VirtualPathData(this, $"{prefixName}/{parameterObj.ToString()}".ToLowerInvariant());
        }
        return null;
    }
}

用法

public class RouteConfig
{
    public static void RegisterRoutes(RouteCollection routes)
    {
        routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

        routes.Add(new EndsWithRoute(
            controllerName: "Template",
            actionName: "Index",
            prefixName: "templates",
            parameterName: "templateFilename"));

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

这将匹配这些 URL：

http://localhost/templates/t1
http://localhost/foo/bar/templates/t2

并将它们都发送到TemplateController.Index() 方法，最后一段作为templateFilename 参数。

注意：出于 SEO 的目的，将相同的内容放在多个 URL 上通常不是一种好的做法。如果您这样做，建议使用canonical tag 通知搜索引擎哪个网址是权威的。

See this to accomplish the same in ASP.NET Core.