如何遍历所有路线? [英] How can I loop through all the routes?

问题描述

从一个mvc(2)用户控件内部，我想遍历所有路由值.

From inside a mvc (2) user control, I want to loop through all the route values.

所以，如果我有类似的控制器:

So if I have controllers like:

UserController
AccountController

我需要一个将出现在url中的值的集合，例如:

I need a collection of the values that will appear in the url like:

/user/...
/account/...

即值用户，帐户.

我怎么能得到这个?

我尝试过RouteTables，但无法弄清楚.

I tried RouteTables but couldn't figure it out.

推荐答案

哦，这是一个让我忙一个小时的好问题. 为了实现所需的功能，我们需要了解MVC源代码和一点点反思.

Oh, really a good question to keep my self busy for an hour. To achieve the required functionality , we need to hook into MVC source and little bit of reflections.

1. 默认情况下，路由名称不可用，因此我们需要编写一个路由集合扩展，以将路由名称保存在RouteData令牌中.

1. By default Route names are not available , so we need to write a Route collection extension to save Route Name in RouteData tokens.

public static Route MapRouteWithName(this RouteCollection routes,string name, string   url, object defaults=null, object constraints=null)
{

Route route = routes.MapRoute(name, url, defaults, constraints);
route.DataTokens = new RouteValueDictionary();
route.DataTokens.Add("RouteName", name);
return route;
}

修改global.asax maproute调用以调用先前的扩展

Modify the global.asax maproute call to invoke previous extension

routes.MapRouteWithName(
            "Default", // Route name
            "{controller}/{action}/{id}", // URL with parameters
            new { controller = "Home", action = "Index", id = UrlParameter.Optional } // Parameter defaults
        );

对MVC PathHelper进行了一些修改.(在项目中包括此帮助器)

Modified the MVC PathHelper a little bit.(Include this helper in the project)

using System;
using System.Collections.Specialized;
using System.Web;

public static class PathHelpers
{

// this method can accept an app-relative path or an absolute path for contentPath
public static string GenerateClientUrl(HttpContextBase httpContext, string contentPath)
{
    if (String.IsNullOrEmpty(contentPath))
    {
        return contentPath;
    }

    // many of the methods we call internally can't handle query strings properly, so just strip it out for
    // the time being
    string query;
    contentPath = StripQuery(contentPath, out query);

    return GenerateClientUrlInternal(httpContext, contentPath) + query;
}

private static string GenerateClientUrlInternal(HttpContextBase httpContext, string contentPath)
{
    if (String.IsNullOrEmpty(contentPath))
    {
        return contentPath;
    }

    // can't call VirtualPathUtility.IsAppRelative since it throws on some inputs
    bool isAppRelative = contentPath[0] == '~';
    if (isAppRelative)
    {
        string absoluteContentPath = VirtualPathUtility.ToAbsolute(contentPath, httpContext.Request.ApplicationPath);
        string modifiedAbsoluteContentPath = httpContext.Response.ApplyAppPathModifier(absoluteContentPath);
        return GenerateClientUrlInternal(httpContext, modifiedAbsoluteContentPath);
    }

    string relativeUrlToDestination = MakeRelative(httpContext.Request.Path, contentPath);
    string absoluteUrlToDestination = MakeAbsolute(httpContext.Request.RawUrl, relativeUrlToDestination);
    return absoluteUrlToDestination;
}

public static string MakeAbsolute(string basePath, string relativePath)
{
    // The Combine() method can't handle query strings on the base path, so we trim it off.
    string query;
    basePath = StripQuery(basePath, out query);
    return VirtualPathUtility.Combine(basePath, relativePath);
}

public static string MakeRelative(string fromPath, string toPath)
{
    string relativeUrl = VirtualPathUtility.MakeRelative(fromPath, toPath);
    if (String.IsNullOrEmpty(relativeUrl) || relativeUrl[0] == '?')
    {
        // Sometimes VirtualPathUtility.MakeRelative() will return an empty string when it meant to return '.',
        // but links to {empty string} are browser dependent. We replace it with an explicit path to force
        // consistency across browsers.
        relativeUrl = "./" + relativeUrl;
    }
    return relativeUrl;
}

private static string StripQuery(string path, out string query)
{
    int queryIndex = path.IndexOf('?');
    if (queryIndex >= 0)
    {
        query = path.Substring(queryIndex);
        return path.Substring(0, queryIndex);
    }
    else
    {
        query = null;
        return path;
    }
}

}

在控制器中添加一些辅助方法

Add few Helper methods in controller

public static string GenerateUrl(string routeName, string actionName, string controllerName, RouteCollection routeCollection, RequestContext requestContext)
{

    RouteValueDictionary mergedRouteValues = MergeRouteValues(actionName, controllerName);

    VirtualPathData vpd = routeCollection.GetVirtualPathForArea(requestContext, routeName, mergedRouteValues);
    if (vpd == null)
    {
        return null;
    }

    string modifiedUrl = PathHelpers.GenerateClientUrl(requestContext.HttpContext, vpd.VirtualPath);
    return modifiedUrl;
}
public static RouteValueDictionary MergeRouteValues(string actionName, string controllerName)
{
    // Create a new dictionary containing implicit and auto-generated values
    RouteValueDictionary mergedRouteValues = new RouteValueDictionary();

    // Merge explicit parameters when not null
    if (actionName != null)
    {
        mergedRouteValues["action"] = actionName;
    }

    if (controllerName != null)
    {
        mergedRouteValues["controller"] = controllerName;
    }

    return mergedRouteValues;
}

现在，我们可以编写一些反射逻辑来读取控制器，操作和路由名称.

Now we can write some reflection logics to read controllers, actions and routenames.

Dictionary<string, List<string>> controllersAndActions = new Dictionary<string, List<string>>();

// Get all the controllers
var controllers = Assembly.GetExecutingAssembly().GetTypes().Where(t => typeof(Controller).IsAssignableFrom(t));

foreach (var controller in controllers)
{
    List<string> actions = new List<string>();
    //Get all methods without HttpPost and with return type action result
    var methods = controller.GetMethods().Where(m => typeof(ActionResult).IsAssignableFrom(m.ReturnType)).Where(a=>!a.GetCustomAttributes(typeof(HttpPostAttribute),true).Any());
    methods.ToList().ForEach(a => {
        actions.Add(a.Name);
    });
    var controllerName = controller.Name;
    if (controllerName.EndsWith("Controller"))
    {
        var nameLength = controllerName.Length - "Controller".Length;
        controllerName = controllerName.Substring(0, nameLength);
    }
    controllersAndActions.Add(controllerName, actions);
}
List<string> allowedRoutes = new List<string>();

var routeNames = RouteTable.Routes.Where(o=>o.GetRouteData(this.HttpContext)!=null).Select(r=>r.GetRouteData(this.HttpContext).DataTokens["RouteName"].ToString());
foreach (var cName in controllersAndActions)
{
    foreach (var aName in cName.Value)
    {
        foreach (var item in routeNames)
        {
            allowedRoutes.Add(GenerateUrl(item, aName, cName.Key, RouteTable.Routes, this.Request.RequestContext));
        }
    }

}

要记住的要点:如果在路由中定义了任何默认参数，则这些控制器和操作的url将为空.例如在上面的示例中，"/Home/Index"将显示为"/"

Points to remember :If in the route you have defined any default parameters, then url for those controller and action will be empty. e.g. in above example "/Home/Index" will be shown as "/"

下载示例应用程序下载链接

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