第四篇 基于.net搭建热插拔式web框架（RazorEngine实现）_html/css_WEB-ITnose

在开头也是先给大家道个歉，由于最近准备婚事导致这篇文章耽误了许久，同时也谢谢老婆大人对我的支持。

回顾上篇文章，我们重造了一个controller，这个controller中用到了视图引擎，我们的视图引擎虽然也叫Razor，但此Razor非mvc中的Razor，MVC中的Razor同样依赖于HttpContext,我们实现的Razor借用 RazorEngine 。关于 RazorEngine的更多介绍请参阅http://antaris.github.io/RazorEngine/。

在上篇文章中无论是View方法还是PartialView方法，都用到了CompileView对象，我们先来看一下 CompileView类的实现。

/// 
    /// 视图编译类    /// 
    public class CompileView    {        private static Regex layoutEx = new Regex("Layout\\s*=\\s*@?\"(\\S*)\";");//匹配视图中的layout        static InvalidatingCachingProvider cache = new InvalidatingCachingProvider();        static FileSystemWatcher m_Watcher = new FileSystemWatcher();        static CompileView()        {            var config = new TemplateServiceConfiguration();            config.BaseTemplateType = typeof(HuberImplementingTemplateBase);            config.ReferenceResolver = new HuberReferenceResolver();            config.CachingProvider = cache;            cache.InvalidateAll();            Engine.Razor = RazorEngineService.Create(config);            //添加文件修改监控，以便在cshtml文件修改时重新编译该文件            m_Watcher.Path = HuberVariable.CurWebDir;            m_Watcher.IncludeSubdirectories = true;            m_Watcher.Filter = "*.*";            m_Watcher.NotifyFilter = NotifyFilters.LastWrite | NotifyFilters.FileName;            m_Watcher.Created += new FileSystemEventHandler(OnChanged);            m_Watcher.Changed += new FileSystemEventHandler(OnChanged);            m_Watcher.Deleted += new FileSystemEventHandler(OnChanged);            m_Watcher.EnableRaisingEvents = true;        }        //当视图被修改后清除缓存        private static void OnChanged(object sender, FileSystemEventArgs e)        {            if (e.FullPath.EndsWith(".cshtml"))            {                string s = e.FullPath.Replace(HuberVariable.CurWebDir, "/");                var key = Engine.Razor.GetKey(s);                cache.InvalidateCache(key);            }        }        public CompileView()        {        }        public string RunCompile(ITemplateKey key, Type modelType, object model, DynamicViewBag viewBag)        {            //判断唯一视图的缓存            string path = (HuberVariable.CurWebDir + key.Name).Replace(@"\\", @"\");            ICompiledTemplate cacheTemplate;            cache.TryRetrieveTemplate(key, null, out cacheTemplate);            if (cacheTemplate == null || !cacheTemplate.Key.Name.Trim().Equals(key.Name.Trim()))            {                CompileViewAndLayout(key, null, model, viewBag);            }            //当缓存存在返回结果            return Engine.Razor.RunCompile(key, null, model, viewBag);        }        /// 
        /// 编译视图和层layout        /// 
        /// 视图的唯一路径        /// 视图类型 :视图/layout        /// 页面 MODEL        /// viewBag        public void CompileViewAndLayout(ITemplateKey key, Type modelType, object model, DynamicViewBag viewBag)        {            //获取视图            string FullPath = (HuberVariable.CurWebDir + key.Name.Replace("/", @"\")).Replace(@"\\", @"\");            string content = System.IO.File.ReadAllText(FullPath);            //匹配layout            var matchs = layoutEx.Matches(content);            string layoutPath = string.Empty;            if (matchs != null)            {                foreach (Match m in matchs)                {                    layoutPath = m.Groups[1].Value;                }            }            if (layoutPath != string.Empty)            {                //添加layout到模板                string FullLayoutPath = (HuberVariable.CurWebDir + layoutPath.Replace("/", @"\")).Replace(@"\\", @"\");                if (File.Exists(FullLayoutPath))                {                    ITemplateKey layoutKey = Engine.Razor.GetKey(layoutPath, ResolveType.Layout);                    CompileViewAndLayout(layoutKey, null, model, viewBag);                }            }            if (key.TemplateType == ResolveType.Layout)            {                Engine.Razor.AddTemplate(key, content);            }            else            {                //编译视图                Engine.Razor.RunCompile(content, key, null, model);            }        }    }

InvalidatingCachingProvider是RazorEngine对视图文件编译结果的一种缓存策略，RazorEngine提供的缓存策略还有DefaultCachingProvider，也可以自己实现一种缓存策略只要继承ICachingProvider。

HuberImplementingTemplateBase：我们自定义的一种Razor模板标签，如“@Html.Raw”，这个例子也可以在RazorEngine官方文档中找到。我们还可以按照规则定义更多用法，下边是我的一些实现：

  1 /// 
页面帮助类  2     /// A simple helper demonstrating the @Html.Raw  3     /// 
  4     ///   5     public class HuberImplementingTemplateBase : TemplateBase  6     {  7         /// 
  8         /// A simple helper demonstrating the @Html.Raw  9         /// 
 10         public HuberImplementingTemplateBase() 11         { 12             Html = new RazorHtmlHelper(); 13         } 14  15         /// 
 16         /// A simple helper demonstrating the @Html.Raw 17         ///  18         /// 
 19         public RazorHtmlHelper Html { get; set; } 20    21     } 22  23 public class RazorHtmlHelper 24     { 25  26         /// 
 27         /// 调用Action视图 28         /// 
 29         /// action方法名称 30         /// 控制器名称 31         ///  32         public IEncodedString Action(string actionName, string controllerName) 33         { 34             return Action(actionName, controllerName, new { }); 35  36         } 37  38         /// 
 39         /// 调用Action视图 40         /// 
 41         ///  42         ///  43         /// 传入参数 44         ///  45         public IEncodedString Action(string actionName, string controllerName, object routeValues) 46         { 47             RefRequestEntity paras = SetParamValue(routeValues); 48  49             var t = HuberHttpModule.CurDomainAssembly.GetType(HuberHttpModule.CurDomainAssemblyName + ".Controllers." + controllerName + "Controller"); 50             var m = t.GetMethod(actionName); 51             object dObj = Activator.CreateInstance(t); 52             object result = m.Invoke(dObj, new object[] { paras }); 53             return new RawString((result as RefRespondEntity).ResultContext.ToString()); 54         } 55  56         /// 
 57         /// 根据model设置传入参数 58         /// 
 59         ///  60         ///  61         private static RefRequestEntity SetParamValue(object routeValues) 62         { 63             RefRequestEntity paras = new RefRequestEntity(); 64  65             Type t1 = routeValues.GetType(); 66             PropertyInfo[] pis = t1.GetProperties(); 67             foreach (PropertyInfo pi in pis) 68             { 69                 paras.Request.Add(pi.Name, pi.GetValue(routeValues)); 70  71             } 72             return paras; 73         } 74  75  76         public IEncodedString RenderAction(string actionName, string controllerName) 77         { 78             return Action(actionName, controllerName, new { }); 79         } 80  81         public IEncodedString RenderAction(string actionName, string controllerName, object routeValues) 82         { 83             return Action(actionName, controllerName, routeValues); 84         } 85  86         public IEncodedString RenderPartial(string partialViewName, string controllerName) 87         { 88             return RenderPartial(partialViewName, controllerName, new { }, new DynamicViewBag()); 89         } 90  91         // Renders the partial view with the given view data and, implicitly, the given view data's model 92         public IEncodedString RenderPartial(string partialViewName, string controllerName, DynamicViewBag ViewBag) 93         { 94             return RenderPartial(partialViewName, controllerName, new { }, ViewBag); 95         } 96  97         // Renders the partial view with an empty view data and the given model 98         public IEncodedString RenderPartial(string partialViewName, string controllerName, object model) 99         {100             return RenderPartial(partialViewName, controllerName, model, new DynamicViewBag());101         }102 103 104         // Renders the partial view with a copy of the given view data plus the given model105         /// 
106         /// 部分视图107         /// 
108         /// 部分视图名称109         /// 控制器名称110         ///  model111         /// ViewBag112         /// 113         public IEncodedString RenderPartial(string partialViewName, string controllerName, object model, DynamicViewBag ViewBag)114         {115 116 117             RefRequestEntity paras = SetParamValue(model);118 119             var t = HuberHttpModule.CurDomainAssembly.GetType(HuberHttpModule.CurDomainAssemblyName + ".Controllers." + controllerName + "Controller");120             var ActionFunc = t.GetMethod(partialViewName);121             object dObj = Activator.CreateInstance(t);122 123             var AddViewBageFunc = t.GetMethod("AddViewBageValues");124 125             foreach (string key in ViewBag.GetDynamicMemberNames())126             {127 128                 AddViewBageFunc.Invoke(dObj, new object[] { key, Impromptu.InvokeGet(ViewBag, key) });129             }130 131             object result = ActionFunc.Invoke(dObj, new object[] { paras });132             return new RawString((result as RefRespondEntity).ResultContext.ToString());133         }134 135     }View Code

HuberReferenceResolver：我们定义的Razor中用的类库依赖。

 1 public class HuberReferenceResolver : IReferenceResolver 2     { 3  4         static List compilerReference; 5         static HuberReferenceResolver() 6         { 7             //加载本地所有类库,@using 使用 8             compilerReference = new List(); 9             IEnumerable loadedAssemblies = (new UseCurrentAssembliesReferenceResolver())10                 .GetReferences(null, null)11                 .Select(r => r.GetFile())12                 .ToArray();13             foreach (var l in loadedAssemblies)14             {15                 compilerReference.Add(CompilerReference.From(l));16             }17 18 19 20         }21 22         public string FindLoaded(IEnumerable refs, string find)23         {24             return refs.First(r => r.EndsWith(System.IO.Path.DirectorySeparatorChar + find));25         }26         public IEnumerable GetReferences(TypeContext context, IEnumerable includeAssemblies)27         {28 29             #region 加载依赖程序集  此处是加载所有程序集，效率需要改进30 31             return compilerReference;32             #endregion33         }34     }View Code

CompileViewAndLayout()是编译视图文件的主要部分，其中有路径的转换、key的定义规则等。

获取视图文件对应编译后的缓存key： Engine.Razor.GetKey()；

编译模板文件（即layout部分）： Engine.Razor.AddTemplate();

编译视图文件： Engine.Razor.RunCompile()。

转载请注明出处：http://www.cnblogs.com/eric-z/p/5102718.html