修改 mao47 对最新 razor 语法的回答，这也将支持部分视图和许多其他辅助方法，因为它使 Microsoft 的辅助方法脱离 System.Web.Mvc.dll 而不仅仅是重新创建它们的一些方法。
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);
}
}
}
}
}