Asp.net MVC 自定义ViewEngine的简单实现

   Asp.net MVC 网站换肤需要使用不同模板，可以通过自定义视图引擎来实现这个功能。这里我偷懒，直接继承 VirtualPathProviderViewEngine来实现。

  核心代码如下：

  ThemeViewEngine.cs

   

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;

namespace MvcSkinDemo.Code
{
    public class ThemeViewEngine : VirtualPathProviderViewEngine
    {
        private string _theme;
        /// <summary>
        /// 使用的主题名称
        /// </summary>
        public string Theme
        {
            get { return _theme; }
            set
            {
                _theme = string.IsNullOrEmpty(value) ? "Default" : value;
                SetLocationFormats(_theme);
            }
        }

        public ThemeViewEngine(string themeName)
        {
            Theme = themeName;
        }

        /// <summary>
        /// 设置视图的搜索路径集合
        /// </summary>
        /// <param name="themeName">主题名</param>
        private void SetLocationFormats(string themeName)
        {
            base.MasterLocationFormats = new[] {
                "~/Views/Themes/" + themeName + "/{1}/{0}.master",
                "~/Views/Themes/" + themeName + "/Shared/{0}.master",
                "~/Views/Themes/Shared/{0}.master"
            };

            base.ViewLocationFormats = new[] {
                "~/Views/Themes/" + themeName + "/{1}/{0}.aspx",
                "~/Views/Themes/" + themeName + "/{1}/{0}.ascx",
                "~/Views/Themes/" + themeName + "/Shared/{0}.aspx",
                "~/Views/Themes/" + themeName + "/Shared/{0}.ascx",
                "~/Views/Themes/Shared/{1}/{0}.aspx",
                "~/Views/Themes/Shared/{1}/{0}.ascx",
                "~/Views/Themes/Shared/{0}.aspx",
                "~/Views/Themes/Shared/{0}.ascx"
            };

            base.PartialViewLocationFormats = base.ViewLocationFormats;
        }

        protected override IView CreatePartialView(ControllerContext controllerContext, string partialPath)
        {
            return new WebFormView(partialPath);
        }

        protected override IView CreateView(ControllerContext controllerContext, string viewPath, string masterPath)
        {
            return new WebFormView(viewPath, masterPath);
        }
    }
}

   Global.asax 设置如下：

   protected void Application_Start()
        {
            AreaRegistration.RegisterAllAreas();

            ///初始化ViewEngine
            InitViewEngine();

            RegisterRoutes(RouteTable.Routes);
        }

        private void InitViewEngine()
        {
            
            ViewEngines.Engines.Clear();
            //在RC中目前还没找到好的在Controller中修改ViewEngine的办法
            //只好在这里将顺序换一下，对性能有一点影响
            //ViewEngines.Engines.Add(new ThemeViewEngine(theme));
           
            ViewEngines.Engines.Add(new ThemeViewEngine("default"));
        }

切换视图引擎：



  (ViewEngines.Engines[0] as ThemeViewEngine).Theme = "green";

 项目结构如下：

  如果你想定义强大的视图引擎，可以参考这个：

  http://www.cnblogs.com/webabcd/archive/2009/05/14/1456453.html