为ASP.NET MVC 2.0添加Razor模板引擎 (on .NET4)

根据ScottGu的博客记述(http://weblogs.asp.net/scottgu/archive/2010/07/02/introducing-razor.aspx),在未来不久将会发布一个ASP.NET MVC 3.0的Preview版本,在这个版本中可以使用多个内置的模板引擎,以它发布出来的截图来看,其中包括NHaml,Spark以及微软刚刚发布的ASP.NET Web Pages(Razor)。 ASP.NET Web Pages包含在Web Matrix中,提供了一种新的模板模式,其扩展名为 .vbhtml/.cshtml,可以使用类似以下语法来做视图显示:

@{
	var i = 11;
}

@(i+1)
<br>

@if (i%2==1){
	<p>true</p>
}else{
	<p>false</p>
}

输出结果为:

12
<br>
 
<p>true</p>

在不久之后Ms还会对此提供Visual Studio 高亮及智能感知支持。

这种模板如此简捷,如果能用在现有的ASP.NET MVC 2.0上做为一个模板引擎是不错的。

首先我们要安装ASP.NET Web Pages,下载地址:http://bbs.eice.com.cn/showtopic-409.aspx ,当然直接安装WebMatrix也是可以。

安装之后在IIS中就会添加对cshtml及vbhtml的支持。

安装后程序集文件会被复制到Program Files\Microsoft ASP.NET\ASP.NET Web Pages\v1.0\Assemblies目录下。

其中包括

Microsoft.Data.dll
Microsoft.Web.Infrastructure.dll
Microsoft.Webpages.Compilation.dll
Microsoft.Webpages.Configuration.dll
Microsoft.Webpages.dll
Microsoft.Webpages.Helpers.dll
Microsoft.Webpages.Helpers.Toolkit.dll

下面我们就动手对ASP.NET MVC程序添加一个Razor的模板引擎:

首先建立一个ASP.NET MVC的项目,然后对其中的Web.Config的system.web/compilation/assemblies节点上添加内容:

<add assembly="Microsoft.WebPages.Compilation, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
<add assembly="Microsoft.Data, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
<add assembly="Microsoft.WebPages.Helpers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
<add assembly="Microsoft.WebPages, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>


并对system.web/compilation/buildProviders添加内容:

<add extension=".cshtml" type="Microsoft.WebPages.Compilation.InlinePageBuildProvider" />

 

并引用相应的

Microsoft.Data.dll 
Microsoft.Webpages.dll 
Microsoft.Webpages.Helpers.dll 
Microsoft.Webpages.Compilation.dll 

几个文件

准备工作做好了,下面就来实现相应的模板引擎,我们先来实现一个IView对象:

public class WebPageView : IView
    {
        public WebPageView(string viewPath)
            : this(viewPath, null)
        {
        }

        public WebPageView(string viewPath, string masterPath)
        {
            if (string.IsNullOrEmpty(viewPath))
            {
                throw new ArgumentException("viewPath can't null", "viewPath");
            }
            this.ViewPath = viewPath;
            this.MasterPath = masterPath ?? string.Empty;
        }

        public virtual void Render(ViewContext viewContext, TextWriter writer)
        {
            if (viewContext == null)
            {
                throw new ArgumentNullException("viewContext");
            }
            WebPage page = WebPage.CreateInstanceFromVirtualPath(this.ViewPath);//load cshtml file
            if (page == null)
            {
                throw new InvalidOperationException("cshtml file not exists");
            }
            else
            {
                this.RenderViewPage(viewContext, page);
            }
        }

        private void RenderViewPage(ViewContext context, WebPage page)
        {
            if (!string.IsNullOrEmpty(this.MasterPath))
            {
                page.LayoutPage = this.MasterPath;
            }
            page.VirtualPath = this.ViewPath;
            page.ExecutePageHierarchy(CreatePageContext(context)
                , context.HttpContext.Response.Output, null);
            //execute cshtml file
        }

        internal static WebPageContext CreatePageContext(ViewContext content)
        {
            var pc = new WebPageContext();
            var t = pc.GetType();
            t.InvokeMember("HttpContext", BindingFlags.SetProperty | BindingFlags.NonPublic | BindingFlags.Instance
                , null, pc, new[] { content.HttpContext });
            t.InvokeMember("ViewContext", BindingFlags.SetProperty
                | BindingFlags.NonPublic | BindingFlags.Instance
                , null, pc, new[] { content });
            return pc;
        }

        /// <summary>Gets or sets the master path.</summary>
        /// <returns>The master path.</returns>
        public string MasterPath { get; private set; }

        /// <summary>Gets or sets the view path.</summary>
        /// <returns>The view path.</returns>
        public string ViewPath { get; private set; }
    }

 

然后我们再来实现一个IViewEngine对象:

    /// <summary>
    /// WebPage View Engine
    /// </summary>
    class WebPageEngine : VirtualPathProviderViewEngine
    {
       
        public WebPageEngine()
        {
            // how to find the template path
            base.MasterLocationFormats = new string[] { 
                "~/Views/{1}/{0}.cshtml", 
                "~/Views/Shared/{0}.cshtml" 
            };
            base.AreaMasterLocationFormats = new string[] { 
                "~/Areas/{2}/Views/{1}/{0}.cshtml", 
                "~/Areas/{2}/Views/Shared/{0}.cshtml"
            };
            base.ViewLocationFormats = new string[] { 
                "~/Views/{1}/{0}.cshtml", 
               "~/Views/Shared/{0}.cshtml"
            };
            base.AreaViewLocationFormats = new string[] { 
                "~/Areas/{2}/Views/{1}/{0}.cshtml", 
                "~/Areas/{2}/Views/Shared/{0}.cshtml" 
            };
            base.PartialViewLocationFormats = base.ViewLocationFormats;
            base.AreaPartialViewLocationFormats = base.AreaViewLocationFormats;
        }

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

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

    }

 

这样我们就实现了Razor的模板引擎了,我们只要在Global.asax中将模板引擎添加进去:

        protected void Application_Start()
        {
            AreaRegistration.RegisterAllAreas();
            RegisterRoutes(RouteTable.Routes);
            ViewEngines.Engines.Clear();
            ViewEngines.Engines.Add(new WebPageEngine());
        }

 

并且将Global的基类改为WebPageHttpApplication:

public class MvcApplication : WebPageHttpApplication
{
//...
}

这样整个程序就可以工作了

我们在Views/Home下添加一个Index.cshtml:

@Html.ActionLink("Home","index","User")
<br>
@ViewData["Message"]

 

这样在我们访问/Home/Index的时候就可以得到ASP.NET MVC默认工程的HomeController.Index所生成的页面了:

<a href="/User">Home</a>
<br>
欢迎使用 ASP.NET MVC!

 

可见在这个模板引擎中,先天对ASP.NET MVC有良好的支持,本身已经集成了Helper、ViewData等诸多ASP.NET MVC的特性。

让我们期待ASP.NET MVC 3.0及Razor对VS的支持吧

8189E6B8-FBE4-4F01-8F9F-5687C0EA9F59

posted @ 2010-07-10 18:09  重典  阅读(12568)  评论(34编辑  收藏  举报