RazorEngine问题与@Html

RazorEngine issues with @Html

我正在使用RazorEngine渲染一些基本内容(一个非常粗糙的内容管理系统)。

直到我将任何@Html语法包含在标记中之前，它的效果都很好。

如果标记包含@html，则会出现以下错误：

Unable to compile template. The name 'Html' does not exist in the
current context

这是呈现标记的视图：

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@Model Models.ContentPage

@{
ViewBag.Title = Model.MetaTitle;
Layout ="~/Views/Shared/Templates/_" + Model.Layout +"Layout.cshtml";

}
@Html.Raw(RazorEngine.Razor.Parse(Model.Markup, Model))

我已经在RazorEngine的Codeplex站点上看到@Html的使用(我知道那里的版本已经过时，并且我是通过nuget获得版本的)。

任何帮助都会很棒。

相关讨论

检查https://github.com/Antaris/RazorEngine/wiki/6.-Encoding-Values页面。我在这里复制/粘贴它：

默认情况下，RazorEngine配置为编码为HTML。当您希望按原样输出时，有时会出现某些字符编码为HTML的问题。

要以原始格式输出内容，请使用@Raw()内置方法，如以下示例所示：

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string template ="@Raw(Model.Data)";
var model = new { Data ="My raw double quotes appears here \"hello!\"" };

string result = Razor.Parse(template, model);

这应导致：

1	My raw double quotes appears here"hello!"

相关讨论

Html和Url助手属性是MVC在其视图引擎中实现Razor的实际功能。如果不专门定制自定义基础模板，则当前不支持Html和Url。

即将发布的v3版本将与相关的RazorEngine.Web版本一起发布，该版本将有望包含具有Html和Url支持的MVC3兼容基本模板。

我在项目主页上编写的示例纯粹是使用自定义基本模板的示例。

您可以在https://github.com/Antaris/RazorEngine上找到有关v3的更多信息。

相关讨论

这是一个很老的问题，但是我在coderwall上找到了很好的答案。解决方案是使用：

1	@(new RawString("Bold!"))

要不就：

1	@(new RawString(Model.YourHTMLStrinInModel))

希望对您有所帮助。

相关讨论

这已经一年多了，但是由于我没有在互联网上的任何地方找到工作副本，并且github页面处于非活动状态，所以我想我会分享我的实现，以向RazorEngine添加@Html帮助器语法。这是我最后得到的实施，以Abu Haider的实施为起点。

感谢miketrash的评论：如果尝试使用@ Html.Action()，则需要添加RequestContext(可以使用HttpContext.Current.Request.RequestContext)。我没有包括请求上下文，因为它并不总是可用于我的应用程序。

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[RequireNamespaces("System.Web.Mvc.Html")]
public class HtmlTemplateBase< T >:TemplateBase< T >, IViewDataContainer
{
private HtmlHelper< T > helper = null;
private ViewDataDictionary viewdata = null;

public HtmlHelper< T > Html
{
get
{
if (helper == null)
{
var writer = this.CurrentWriter; //TemplateBase.CurrentWriter
var vcontext = new ViewContext() { Writer = writer, ViewData = this.ViewData};

helper = new HtmlHelper< T >(vcontext, this);
}
return helper;
}
}

public ViewDataDictionary ViewData
{
get
{
if (viewdata == null)
{
viewdata = new ViewDataDictionary();
viewdata.TemplateInfo = new TemplateInfo() { HtmlFieldPrefix = string.Empty };

if (this.Model != null)
{
viewdata.Model = Model;
}
}
return viewdata;
}
set
{
viewdata = value;
}
}

public override void WriteTo(TextWriter writer, object value)
{
if (writer == null)
throw new ArgumentNullException("writer");

if (value == null) return;

//try to cast to RazorEngine IEncodedString
var encodedString = value as IEncodedString;
if (encodedString != null)
{
writer.Write(encodedString);
}
else
{
//try to cast to IHtmlString (Could be returned by Mvc Html helper methods)
var htmlString = value as IHtmlString;
if (htmlString != null) writer.Write(htmlString.ToHtmlString());
else
{
//default implementation is to convert to RazorEngine encoded string
encodedString = TemplateService.EncodedStringFactory.CreateEncodedString(value);
writer.Write(encodedString);
}

}
}
}

我还必须重写TemplateBase的WriteTo方法，因为否则RazorEngine将对辅助方法的结果进行html编码，这意味着您将转义'<'，'>'和引号(请参阅此问题)。覆盖在执行编码之前添加了对值为IHtmlString的检查。

相关讨论

抱歉，我没有50条信誉才能添加评论，因此必须提出答案。

如果有人想知道(就像JamesStuddart一样)，则缺少SetTemplateBase()方法，但是您可以创建一个配置实例以使用基本模板初始化服务。

来自http://razorengine.codeplex.com/discussions/285937，我修改了代码，如下所示：

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var config = new RazorEngine.Configuration.TemplateServiceConfiguration
{
BaseTemplateType = typeof(MyHtmlTemplateBase<>)
};

using (var service = new RazorEngine.Templating.TemplateService(config))
{
// Use template service.
Razor.SetTemplateService(service);
result = Razor.Parse(templateString, model);
}

我的答案使用了hannes neukermans的答案。

我需要使用RazorEngine发送包含存储在数据库中的html字符串的电子邮件，以便管理员用户可以对其进行编辑。

标准配置不允许@ Html.Raw工作。

在我的电子邮件课程中，我设置了一个新的Engine.Razor(Engine是静态的)，其中包含了Hannes建议的课程。我只需要Raw方法，但是您显然可以添加其他方法：

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public class HtmlSupportTemplateBase< T > : TemplateBase< T >
{
public HtmlSupportTemplateBase()
{
Html = new MyHtmlHelper();
}
public MyHtmlHelper Html { get; set; }
}

public class MyHtmlHelper
{
/// <summary>
/// Instructs razor to render a string without applying html encoding.
/// </summary>
/// <param name="htmlString"></param>
/// <returns></returns>
public IEncodedString Raw(string htmlString)
{
return new RawString(WebUtility.HtmlEncode(htmlString));
}
}

然后，我可以在电子邮件模板中使用@ Html.Raw来合并可编辑的html。

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public class Emails
{
public static TemplateServiceConfiguration config
= new TemplateServiceConfiguration(); // create a new config

public Emails()
{
config.BaseTemplateType = typeof(HtmlSupportTemplateBase<>);// incorporate the Html helper class
Engine.Razor = RazorEngineService.Create(config);// use that config to assign a new razor service
}

public static void SendHtmlEmail(string template, EmailModel model)
{
string emailBody
= Engine.Razor.RunCompile(template, model.Type.ToString(), typeof(EmailModel), model);

以下内容并不是答案的真正组成部分，但为使用它发送电子邮件的人提供了有用的代码:)

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var smtpClient = getStaticSmtpObject(); // an external method not included here
MailMessage message = new MailMessage();
message.From = new MailAddress(model.FromAddress);
message.To.Add(model.EmailAddress);
message.Subject = model.Subject;
message.IsBodyHtml = true;
message.Body = System.Net.WebUtility.HtmlDecode(emailBody);
smtpClient.SendAsync(message, model);
}
}

然后，我可以通过传入从实际的.cshtml模板读取的字符串和包含电子邮件数据的模型来使用它。 (ResolveConfigurationPath是我在此页面中找到的另一个外部函数)

1 2	string template = System.IO.File.ReadAllText(ResolveConfigurationPath("~/Views/Emails/MAPEmail.cshtml")); SendHtmlEmail(template, model);

HTML.Raw最简单的解决方案！需要3个步骤

步骤1：从TemplateBase继承：

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public class HtmlSupportTemplateBase< T > : TemplateBase< T >
{
public HtmlSupportTemplateBase()
{
Html = new MyHtmlHelper();
}

public MyHtmlHelper Html { get; set; }

}

步骤2：创建一个对象，使模板使用的所有Html方法可用。
在此示例中，Html.Raw和Html.Encode在cshtml中可用。模板

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public class MyHtmlHelper
{
/// <summary>
/// Instructs razor to render a string without applying html encoding.
/// </summary>
/// <param name="htmlString"></param>
/// <returns></returns>
public IEncodedString Raw(string htmlString)
{
return new RawString(htmlString);
}

public string Encode(string value)
{
return System.Net.WebUtility.HtmlEncode(value);
}

public string Encode(object value)
{
return"do whatever";
}
}

第三步：

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var config = new TemplateServiceConfiguration
{
TemplateManager = templateManager,
BaseTemplateType = typeof(HtmlSupportTemplateBase<>)
};

相关讨论

修改mao47答案以获取最新的剃刀语法，这也将支持部分视图。

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using System;
using System.Collections.Concurrent;
using System.IO;
using System.Linq;
using System.Web.Hosting;
using System.Xml.Linq;
using RazorEngine.Configuration;
using RazorEngine.Templating;
public static class DynamicRazorTemplateParser
{
private static readonly IRazorEngineService service = RazorEngineService.Create(TemplateServiceConfiguration);
public static string RunCompile< T >(string template, string placeholder, T model, DynamicViewBag viewBag) where T : class
{
var templateSource = new LoadedTemplateSource(template);
return RunCompile(templateSource, placeholder, model, viewBag);
}
public static string RunCompile< T >(ITemplateSource template, string placeholder, T model, DynamicViewBag viewBag) where T : class
{
return service.RunCompile(template, placeholder, model.GetType(), model, viewBag);
}
public static string RunCompile(ITemplateSource template, string placeholder)
{

return service.RunCompile(template, placeholder);

}

private static TemplateServiceConfiguration TemplateServiceConfiguration
{
get
{
var config = new TemplateServiceConfiguration
{
BaseTemplateType = typeof(HtmlTemplateBase<>),
TemplateManager = new TemplateManager()
};
//TODO: Is this the best way?
var xDocument = XDocument.Load(AppDomain.CurrentDomain.SetupInformation.ApplicationBase +"/Views/Web.config");
if (xDocument.Root != null)
{
var sysWeb = xDocument.Root.Element("system.web.webPages.razor");
if (sysWeb == null) return config;
var pages = sysWeb.Element("pages");
if (pages != null)
{
var namespaces = pages.Element("namespaces");
if (namespaces != null)
{
var namespacesAdd = namespaces.Elements("add")
.Where(x => x.Attribute("namespace") != null)
.Select(x =>

x.Attribute("namespace").Value
);
foreach (var ns in namespacesAdd)
{
config.Namespaces.Add(ns);
}
}
}
}
return config;
}
}
private class TemplateManager : ITemplateManager
{
private readonly ConcurrentDictionary<ITemplateKey, ITemplateSource> _dynamicTemplates = new ConcurrentDictionary<ITemplateKey, ITemplateSource>();
private readonly string baseTemplatePath;
public TemplateManager()
{
baseTemplatePath = HostingEnvironment.MapPath("~/Views/");
}

public ITemplateSource Resolve(ITemplateKey key)
{
ITemplateSource templateSource;
if (this._dynamicTemplates.TryGetValue(key, out templateSource))
return templateSource;

string template = key.Name;
var ubuilder = new UriBuilder();
ubuilder.Path = template;
var newURL = ubuilder.Uri.LocalPath.TrimStart('/');
string path = Path.Combine(baseTemplatePath, string.Format("{0}", newURL));

string content = File.ReadAllText(path);
return new LoadedTemplateSource(content, path);
}

public ITemplateKey GetKey(string name, ResolveType resolveType, ITemplateKey context)
{
return new NameOnlyTemplateKey(name, resolveType, context);
}

public void AddDynamic(ITemplateKey key, ITemplateSource source)
{
this._dynamicTemplates.AddOrUpdate(key, source, (k, oldSource) =>
{
if (oldSource.Template != source.Template)
throw new InvalidOperationException("The same key was already used for another template!");
return source;
});
}
}
}

using System;
using System.IO;
using System.Web;
using System.Web.Mvc;
using System.Web.Routing;
using RazorEngine.Templating;
using RazorEngine.Text;
// ReSharper disable ClassWithVirtualMembersNeverInherited.Global
// ReSharper disable MemberCanBePrivate.Global

namespace Common.Core.Razor
{
[RequireNamespaces("System.Web.Mvc.Html")]
public class HtmlTemplateBase< T > : RazorEngine.Templating.HtmlTemplateBase< T >, IViewDataContainer
{
private HtmlHelper< T > helper;
private ViewDataDictionary viewdata;
private TempDataDictionary tempdata;
private AjaxHelper< T > ajaxHelper;
private ViewContext viewContext;
private UrlHelper urlHelper;
private readonly RequestContext _requestContext = HttpContext.Current.Request.RequestContext;

public UrlHelper Url => urlHelper ?? (urlHelper = new UrlHelper(_requestContext));

public ViewContext ViewContext
{
get
{
if (viewContext != null) return viewContext;
viewContext = GetViewContext();
return viewContext;
}
}

public AjaxHelper< T > Ajax
{
get
{
if (ajaxHelper != null) return ajaxHelper;
ajaxHelper = new AjaxHelper< T >(ViewContext, this);
return ajaxHelper;
}
}

public HtmlHelper< T > Html
{
get
{
if (helper != null) return helper;
helper = new HtmlHelper< T >(ViewContext, this);
return helper;
}
}

public ViewDataDictionary ViewData
{
get
{
if (viewdata == null)
{
viewdata = new ViewDataDictionary
{
TemplateInfo = new TemplateInfo() { HtmlFieldPrefix = string.Empty }
};

if (Model != null)
{
viewdata.Model = Model;
}
}
return viewdata;
}
set
{
viewdata = value;
}
}
public TempDataDictionary TempData
{
get { return tempdata ?? (tempdata = new TempDataDictionary()); }
set
{
tempdata = value;
}
}
public virtual string RenderView()
{
using (var writer = new StringWriter())
{
ViewContext.View.Render(ViewContext, CurrentWriter);
return writer.GetStringBuilder().ToString();
}
}

private ViewContext GetViewContext()
{
if (HttpContext.Current == null) throw new NotImplementedException();
var requestContext = _requestContext;
var controllerContext = ControllerContext(requestContext);

var view = GetView(requestContext, controllerContext);
//Can't check if string writer is closed, need to catch exception
try
{
var vContext = new ViewContext(controllerContext, view, ViewData, TempData, CurrentWriter);
return vContext;

}
catch
{
using (var sw = new StringWriter())
{
var vContext = new ViewContext(controllerContext, view, ViewData, TempData, sw);
return vContext;
}
}
}

private IView GetView(RequestContext requestContext, ControllerContext controllerContext)
{
if ((string)requestContext.RouteData.DataTokens["Action"] != null)
{
requestContext.RouteData.Values["action"] = (string)requestContext.RouteData.DataTokens["Action"];
}

var action = requestContext.RouteData.GetRequiredString("action");
var viewEngineResult = ViewEngines.Engines.FindPartialView(controllerContext, action);
if (viewEngineResult != null && viewEngineResult.View != null)
{
return viewEngineResult.View;
}

viewEngineResult = ViewEngines.Engines.FindView(controllerContext, action, null);
if (viewEngineResult == null)
{
throw new Exception("No PartialView assigned in route");
}
return viewEngineResult.View;

}

public void SetView(string view)
{
_requestContext.RouteData.DataTokens["Action"] = view;
}

private ControllerContext ControllerContext(RequestContext requestContext)
{
ControllerBase controllerBase;
var routeDataValue ="EmptyController";
if (requestContext.RouteData.Values["controller"] != null && (string)requestContext.RouteData.Values["controller"] != routeDataValue)
{
var controllerName = (string)requestContext.RouteData.Values["controller"];
IController controller = ControllerBuilder.Current.GetControllerFactory().CreateController(requestContext, controllerName);
controllerBase = controller as ControllerBase;
}
else
{

var controller = new EmptyController();
controllerBase = controller; //ControllerBase implements IController which this returns
requestContext.RouteData.Values["controller"] = routeDataValue;
}
var controllerContext =
new ControllerContext(requestContext.HttpContext, requestContext.RouteData, controllerBase);
return controllerContext;
}
private class EmptyController : Controller { }
public override void WriteTo(TextWriter writer, object value)
{
if (writer == null)
throw new ArgumentNullException("writer");

if (value == null) return;

//try to cast to RazorEngine IEncodedString
var encodedString = value as IEncodedString;
if (encodedString != null)
{
writer.Write(encodedString);
}
else
{
//try to cast to IHtmlString (Could be returned by Mvc Html helper methods)
var htmlString = value as IHtmlString;
if (htmlString != null) writer.Write(htmlString.ToHtmlString());
else
{
//default implementation is to convert to RazorEngine encoded string
base.WriteTo(writer, value);

}

}
}
}
}