MVC学习系列——RazorViewEngine扩展

有时候，我们的项目涉及到多种风格，我们可以通过扩展RazorViewEngine，这样就可以保持后台代码不发生变化。

新建类ThemeViewEngine继承于RazorViewEngine

  public class ThemeViewEngine : RazorViewEngine
     {
         public ThemeViewEngine(string theme)
         {
             ViewLocationFormats = new[]
            {
                 "~/Views/Themes/" + theme + "/{1}/{0}.cshtml",
                 "~/Views/Themes/" + theme + "/Shared/{0}.cshtml"
             };

             PartialViewLocationFormats = new[]
             {
                 "~/Views/Themes/" + theme + "/{1}/{0}.cshtml",
                 "~/Views/Themes/" + theme + "/Shared/{0}.cshtml"
             };

             AreaViewLocationFormats = new[]
             {
                 "~Areas/{2}/Views/Themes/" + theme + "/{1}/{0}.cshtml",
                 "~Areas/{2}/Views/Themes/" + theme + "/Shared/{0}.cshtml"
             };

             AreaPartialViewLocationFormats = new[]
             {
                 "~Areas/{2}/Views/Themes/" + theme + "/{1}/{0}.cshtml",
                 "~Areas/{2}/Views/Themes/" + theme + "/Shared/{0}.cshtml"
             };
         }
     }

Global类中，注册这种引擎

   //不同风格
             if (!string.IsNullOrEmpty(ConfigurationManager.AppSettings["Theme"]))
             {
                 var activeTheme = ConfigurationManager.AppSettings["Theme"];
                 ViewEngines.Engines.Insert(, new ThemeViewEngine(activeTheme));
             }

web.config配置具体风格：

 <add key="Theme" value="China" />

项目文件结构：

View:

America:

 @{
     ViewBag.Title = "ShowTheme";
 }

 <h2>ShowTheme   America</h2>

China:

 @{
     ViewBag.Title = "ShowTheme";
 }

 <h2>ShowTheme   China</h2>

运行：

  public ActionResult ShowTheme()
         {
             return View();
         }

效果图: