在ASP.NET 5(vNext)MVC 6中添加自定义IRouter

Question

我正在尝试将此示例RouteBase实现转换为与MVC 6一起使用.我已经通过遵循路由项目中的示例来解决大部分问题,但是我正在了解如何Task从方法返回异步.我真的不在乎它是否实际上是异步的(为任何可以提供答案的人欢呼),现在我只想让它运转起来.

我有传出的路线功能(ActionLink当我输入路线值时,意味着工作正常).问题在于RouteAsync方法.

public Task RouteAsync(RouteContext context)
{
    var requestPath = context.HttpContext.Request.Path.Value;

    if (!string.IsNullOrEmpty(requestPath) && requestPath[0] == '/')
    {
        // Trim the leading slash
        requestPath = requestPath.Substring(1);
    }

    // Get the page that matches.
    var page = GetPageList()
        .Where(x => x.VirtualPath.Equals(requestPath))
        .FirstOrDefault();

    // If we got back a null value set, that means the URI did not match
    if (page != null)
    {
        var routeData = new RouteData();

        // This doesn't work
        //var routeData = new RouteData(context.RouteData);

        // This doesn't work
        //routeData.Routers.Add(this);

        // This doesn't work
        //routeData.Routers.Add(new MvcRouteHandler());

        // TODO: You might want to use the page object (from the database) to
        // get both the controller and action, and possibly even an area.
        // Alternatively, you could create a route for each table and hard-code
        // this information.
        routeData.Values["controller"] = "CustomPage";
        routeData.Values["action"] = "Details";

        // This will be the primary key of the database row.
        // It might be an integer or a GUID.
        routeData.Values["id"] = page.Id;

        context.RouteData = routeData;

        // When there is a match, the code executes to here
        context.IsHandled = true; 

        // This test works
        //await context.HttpContext.Response.WriteAsync("Hello there");

        // This doesn't work
        //return Task.FromResult(routeData);

        // This doesn't work
        //return Task.FromResult(context);
    }

    // This satisfies the return statement, but 
    // I'm not sure it is the right thing to return.
    return Task.FromResult(0);
}

当匹配时,整个方法一直运行到最后.但是当它完成执行时,它不会调用控制器的Details方法CustomPage,因为它应该.我只是在浏览器中看到一个空白的白页.

我WriteAsync在这篇文章中添加了这一行并且它写入Hello there了空白页面,但是我无法理解为什么MVC没有调用我的控制器(在以前的版本中这没有顺利工作).不幸的是,该帖子涵盖了路由的每个部分,除了如何实现IRouter或INamedRouter.

如何使RouteAsync方法起作用？

整个CustomRoute实现

using Microsoft.AspNet.Routing;
using Microsoft.Framework.Caching.Memory;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

public class PageInfo
{
    // VirtualPath should not have a leading slash
    // example: events/conventions/mycon
    public string VirtualPath { get; set; }
    public int Id { get; set; }
}

public interface ICustomRoute : IRouter
{ }


public class CustomRoute : ICustomRoute
{
    private readonly IMemoryCache cache;
    private object synclock = new object();

    public CustomRoute(IMemoryCache cache)
    {
        this.cache = cache;
    }

    public Task RouteAsync(RouteContext context)
    {
        var requestPath = context.HttpContext.Request.Path.Value;

        if (!string.IsNullOrEmpty(requestPath) && requestPath[0] == '/')
        {
            // Trim the leading slash
            requestPath = requestPath.Substring(1);
        }

        // Get the page that matches.
        var page = GetPageList()
            .Where(x => x.VirtualPath.Equals(requestPath))
            .FirstOrDefault();

        // If we got back a null value set, that means the URI did not match
        if (page != null)
        {
            var routeData = new RouteData();

            // TODO: You might want to use the page object (from the database) to
            // get both the controller and action, and possibly even an area.
            // Alternatively, you could create a route for each table and hard-code
            // this information.
            routeData.Values["controller"] = "CustomPage";
            routeData.Values["action"] = "Details";

            // This will be the primary key of the database row.
            // It might be an integer or a GUID.
            routeData.Values["id"] = page.Id;

            context.RouteData = routeData;
            context.IsHandled = true; 
        }

        return Task.FromResult(0);
    }

    public VirtualPathData GetVirtualPath(VirtualPathContext context)
    {
        VirtualPathData result = null;
        PageInfo page = null;

        // Get all of the pages from the cache.
        var pages = GetPageList();

        if (TryFindMatch(pages, context.Values, out page))
        {
            result = new VirtualPathData(this, page.VirtualPath);
            context.IsBound = true;
        }

        return result;
    }

    private bool TryFindMatch(IEnumerable<PageInfo> pages, IDictionary<string, object> values, out PageInfo page)
    {
        page = null;
        int id;
        object idObj;
        object controller;
        object action;

        if (!values.TryGetValue("id", out idObj))
        {
            return false;
        }

        id = Convert.ToInt32(idObj);
        values.TryGetValue("controller", out controller);
        values.TryGetValue("action", out action);

        // The logic here should be the inverse of the logic in 
        // GetRouteData(). So, we match the same controller, action, and id.
        // If we had additional route values there, we would take them all 
        // into consideration during this step.
        if (action.Equals("Details") && controller.Equals("CustomPage"))
        {
            page = pages
                .Where(x => x.Id.Equals(id))
                .FirstOrDefault();
            if (page != null)
            {
                return true;
            }
        }
        return false;
    }

    private IEnumerable<PageInfo> GetPageList()
    {
        string key = "__CustomPageList";
        IEnumerable<PageInfo> pages;

        // Only allow one thread to poplate the data
        if (!this.cache.TryGetValue(key, out pages))
        {
            lock (synclock)
            {
                if (!this.cache.TryGetValue(key, out pages))
                {
                    // TODO: Retrieve the list of PageInfo objects from the database here.
                    pages = new List<PageInfo>()
                    {
                        new PageInfo() { Id = 1, VirtualPath = "somecategory/somesubcategory/content1" },
                        new PageInfo() { Id = 2, VirtualPath = "somecategory/somesubcategory/content2" },
                        new PageInfo() { Id = 3, VirtualPath = "somecategory/somesubcategory/content3" }
                    };

                    this.cache.Set(key, pages,
                        new MemoryCacheEntryOptions()
                        {
                            Priority = CacheItemPriority.NeverRemove,
                            AbsoluteExpirationRelativeToNow = TimeSpan.FromMinutes(15)
                        });
                }
            }
        }

        return pages;
    }
}

CustomRoute DI注册

services.AddTransient<ICustomRoute, CustomRoute>();

MVC路由配置

// Add MVC to the request pipeline.
app.UseMvc(routes =>
{
    routes.Routes.Add(routes.ServiceProvider.GetService<ICustomRoute>());

    routes.MapRoute(
        name: "default",
        template: "{controller=Home}/{action=Index}/{id?}");

    // Uncomment the following line to add a route for porting Web API 2 controllers.
    // routes.MapWebApiRoute("DefaultApi", "api/{controller}/{id?}");
});

如果重要我正在使用Beta 5,DNX 4.5.1并且DNX Core 5.

解

我根据我在这里学到的信息创建了一个通用的解决方案,可以在这个答案中用于URL双向映射的简单主键.在将其连接到MVC 6路由时,可以指定主键的控制器,操作,数据提供程序和数据类型.

Answer 1

正如@opiants所说,问题在于你在RouteAsync方法中什么都不做.

如果您的目的是最终调用控制器操作方法,则可以使用以下方法而不是默认的MVC路由:

默认情况下,MVC使用 TemplateRoute 内部目标IRouter.在RouteAsync中,TemplateRoute将委托给内部IRouter.此内部路由器被设置为 MvcRouteHandler 默认构建器扩展.在您的情况下,首先添加一个IRouter作为您的内部目标:

public class CustomRoute : ICustomRoute
{
    private readonly IMemoryCache cache;
    private readonly IRouter target;
    private object synclock = new object();

    public CustomRoute(IMemoryCache cache, IRouter target)
    {
        this.cache = cache;
        this.target = target;
    }

然后更新您的启动以将该目标MvcRouteHandler设置为已设置为routes.DefaultHandler:

app.UseMvc(routes =>
{
    routes.Routes.Add(
       new CustomRoute(routes.ServiceProvider.GetRequiredService<IMemoryCache>(), 
                       routes.DefaultHandler));

    routes.MapRoute(
        name: "default",
        template: "{controller=Home}/{action=Index}/{id?}");

    // Uncomment the following line to add a route for porting Web API 2 controllers.
    // routes.MapWebApiRoute("DefaultApi", "api/{controller}/{id?}");
});

最后,更新你的AsyncRoute方法来调用内部IRouter,这将是MvcRouteHandler.您可以使用该方法的实现TemplateRoute作为指导.我很快就使用了这种方法并修改了你的方法如下:

public async Task RouteAsync(RouteContext context)
{
    var requestPath = context.HttpContext.Request.Path.Value;

    if (!string.IsNullOrEmpty(requestPath) && requestPath[0] == '/')
    {
        // Trim the leading slash
        requestPath = requestPath.Substring(1);
    }

    // Get the page that matches.
    var page = GetPageList()
        .Where(x => x.VirtualPath.Equals(requestPath))
        .FirstOrDefault();

    // If we got back a null value set, that means the URI did not match
    if (page == null)
    {
        return;
    }


    //Invoke MVC controller/action
    var oldRouteData = context.RouteData;
    var newRouteData = new RouteData(oldRouteData);
    newRouteData.Routers.Add(this.target);

    // TODO: You might want to use the page object (from the database) to
    // get both the controller and action, and possibly even an area.
    // Alternatively, you could create a route for each table and hard-code
    // this information.
    newRouteData.Values["controller"] = "CustomPage";
    newRouteData.Values["action"] = "Details";

    // This will be the primary key of the database row.
    // It might be an integer or a GUID.
    newRouteData.Values["id"] = page.Id;

    try
    {
        context.RouteData = newRouteData;
        await this.target.RouteAsync(context);
    }
    finally
    {
        // Restore the original values to prevent polluting the route data.
        if (!context.IsHandled)
        {
            context.RouteData = oldRouteData;
        }
    }
}

更新RC2

看起来TemplateRoute不再是RC2 aspnet路由.

我调查了历史,它RouteBase在36180ab的更新中被重命名为更大的重构的一部分.