为ASP.NET MVC 1.0添加Areas

       今天闲逛时看到MVC 2.0的一些新特性，其中一样就是：提供域划分功能（Areas）。MVC 1.0刚发布的时候，我就为这个东西纠结过一段时间，后来在老外的Blog上看到了一个简单的解决方案，一直都在用，现整理出来，给有需要的同学做个参考。
      园子里对这个功能关注的人好象不是很多，所以对此功能稍做一下解释。域划分简单的说就是按功能来划分模块。如用户模块(User)及文章模块(Article)，每个模块都有好几个Controller,也许我们需要把模块分别放在独立的命名空间下。在Url上，模块划分体现为：/{Area}/{Controller}/{Action}。（可能我说的不大清楚，尚不明白的请自行到网上搜索）
以下为步骤：
1.把Controller按模块分类。

2.为模块设计路由

3.更换模板引擎（见上图）

4.将视图移至Area文件夹（路径为/{Area}/{Controller}/{Action}）

以下为实现
1.为路由添加area

using System.Web.Routing;



namespace Madnet.DevMvc

{

    public static class RouteHelper

    {

        public static void CreateArea(this RouteCollection routes, string areaName, string[] controllersNamespace, params Route[] routeEntries)

        {

            foreach (var route in routeEntries)

            {

                if (route.Constraints == null) route.Constraints = new RouteValueDictionary();

                if (route.Defaults == null) route.Defaults = new RouteValueDictionary();

                if (route.DataTokens == null) route.DataTokens = new RouteValueDictionary();



                route.Constraints.Add("area", areaName);

                route.Defaults.Add("area", areaName);

                route.DataTokens.Add("namespaces", controllersNamespace);



                if (!routes.Contains(route)) // To support "new Route()" in addition to "routes.MapRoute()"

                    routes.Add(route);

            }

        }

    }

}

 

2.改造模板引擎，以满足基于area的模板路径搜索

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Web.Mvc;



namespace Madnet.DevMvc

{

    public class DefaultViewEngine: WebFormViewEngine

    {

        public DefaultViewEngine()

            : base()

        {

            ViewLocationFormats = new[] { 

                "~/{0}.aspx",

                "~/{0}.ascx",

                "~/Views/{1}/{0}.aspx",

                "~/Views/{1}/{0}.ascx",

                "~/Views/Shared/{0}.aspx",

                "~/Views/Shared/{0}.ascx",

            };



            MasterLocationFormats = new[] {

                "~/{0}.master",

                "~/Shared/{0}.master",

                "~/Views/{1}/{0}.master",

                "~/Views/Shared/{0}.master",

            };



            PartialViewLocationFormats = ViewLocationFormats;

        }

        #region IViewEngine Members

        public override ViewEngineResult FindPartialView(ControllerContext controllerContext, string partialViewName, bool useCache) {

            

            ViewEngineResult areaResult = null;

            

            if (controllerContext.RouteData.Values.ContainsKey("area")) {

                string areaPartialName = FormatViewName(controllerContext, partialViewName);

                areaResult = base.FindPartialView(controllerContext, areaPartialName, useCache);

                if (areaResult != null && areaResult.View != null) {

                    return areaResult;

                }

                string sharedAreaPartialName = FormatSharedViewName(controllerContext, partialViewName);

                areaResult = base.FindPartialView(controllerContext, sharedAreaPartialName, useCache);

                if (areaResult != null && areaResult.View != null) {

                    return areaResult;

                }

            }



            return base.FindPartialView(controllerContext, partialViewName, useCache);

        }



        public override ViewEngineResult FindView(ControllerContext controllerContext, string viewName, string masterName, bool useCache) {

            ViewEngineResult areaResult = null;



            if (controllerContext.RouteData.Values.ContainsKey("area")) {

                string areaViewName = FormatViewName(controllerContext, viewName);

                string masterAreaViewName = FormatMasterViewName(controllerContext, masterName);

                areaResult = base.FindView(controllerContext, areaViewName, masterAreaViewName, useCache);

                if (areaResult != null && areaResult.View != null)

                {

                    return areaResult;

                }



                areaResult = base.FindView(controllerContext, areaViewName, masterName, useCache);

                if (areaResult != null && areaResult.View != null) {

                    return areaResult;

                }



                string sharedAreaViewName = FormatSharedViewName(controllerContext, viewName);

                areaResult = base.FindView(controllerContext, sharedAreaViewName, masterAreaViewName, useCache);

                if (areaResult != null && areaResult.View != null)

                {

                    return areaResult;

                }

                areaResult = base.FindView(controllerContext, sharedAreaViewName, masterName, useCache);

                if (areaResult != null && areaResult.View != null) {

                    return areaResult;

                }

            }



            return base.FindView(controllerContext, viewName, masterName, useCache);

        }

        #endregion IViewEngine Members

        private static string FormatViewName(ControllerContext controllerContext, string viewName)

        {

            string controllerName = controllerContext.RouteData.GetRequiredString("controller");

            string area = controllerContext.RouteData.Values["area"].ToString();

            return "Views/" + (string.IsNullOrEmpty(area) ? "" : (area + "/")) + "/" + controllerName + "/" + viewName;

        }



        private static string FormatSharedViewName(ControllerContext controllerContext, string viewName)

        {

            string area = controllerContext.RouteData.Values["area"].ToString();

            return "Views/" + (string.IsNullOrEmpty(area) ? "" : (area + "/")) + "/Shared/" + viewName;

        }

        private static string FormatMasterViewName(ControllerContext controllerContext, string masterName)

        {

            string area = controllerContext.RouteData.Values["area"].ToString();

            return "Views/" + (string.IsNullOrEmpty(area) ? "" : (area + "/")) + "/Masters/" + masterName;

        }

    }

}

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