有没有办法从非Web应用程序处理MVC视图(aspx文件)？

Question

我有一个后台服务运行,它向我的网站用户发送电子邮件.我想将电子邮件模板编写为MVC视图,以保持一致(以便可以使用相同的模型发送电子邮件以显示网页).

不幸的是,当我尝试执行LoadControl(只是修补到BuildManager.CreateInstanceFromVirtualPath)时,我得到以下内容:

System.NullReferenceException at
  System.Web.dll!System.Web.VirtualPath.GetCacheKey() + 0x26 bytes  
  System.Web.dll!System.Web.Compilation.BuildManager.GetCacheKeyFromVirtualPath + 0x2a bytes
  System.Web.dll!System.Web.Compilation.BuildManager.GetVPathBuildResultFromCacheInternal  + 0x30 bytes

似乎如果我将MvcBuildViews设置为true,那么应该有一些简单的方法来使用编译的视图来构建电子邮件模板,但我无法弄清楚如何.

我从Rick Strahl找到了以下博客,可能会有这样的技巧:http: //www.west-wind.com/presentations/aspnetruntime/aspnetruntime.asp

但是,它似乎启动了一个完整的ASP.NET服务器来处理请求.

有没有一种简单的方法来加载MVC视图并渲染它？或者是Rick Strahl建议的加载ASP.NET运行时的唯一方法？

Answer 1

默认的asp.net视图引擎与asp.net引擎绑定.它与上下文联系在一起,我认为你可以解决它,但它绝对不简单.

问题在于默认的视图引擎+ asp.net引擎组合,其他视图引擎不应该有这个问题.至少火花视图引擎没有.

编辑: OP解决了最后的提示,但fwiw我的版本使用默认的asp.net mvc项目模板的控制器主页索引操作:

public class MyAppHost : MarshalByRefObject
{
    public string RenderHomeIndexAction()
    {
        var controller = new HomeController();
        using (var writer = new StringWriter())
        {
            var httpContext = new HttpContext(new HttpRequest("", "http://example.com", ""), new HttpResponse(writer));
            if (HttpContext.Current != null) throw new NotSupportedException("httpcontext was already set");
            HttpContext.Current = httpContext;
            var controllerName = controller.GetType().Name;
            var routeData = new RouteData();
            routeData.Values.Add("controller", controllerName.Remove(controllerName.LastIndexOf("Controller")));
            routeData.Values.Add("action", "index");
            var controllerContext = new ControllerContext(new HttpContextWrapper(httpContext), routeData, controller);
            var res = controller.Index();
            res.ExecuteResult(controllerContext);
            HttpContext.Current = null;
            return writer.ToString();
        }
    }
}

......来自一个单独的项目:

    [TestMethod]
    public void TestIndexAction()
    {
        var myAppHost = (MyAppHost)ApplicationHost.CreateApplicationHost(
            typeof(MyAppHost), "/", @"c:\full\physical\path\to\the\mvc\project");
        var view = myAppHost.RenderHomeIndexAction();
        Assert.IsTrue(view.Contains("learn more about"));

    }

一些额外的说明:

• 新的HttpRequest中的url无关紧要,但需要是一个有效的url
• 它不是要从已经有上下文的asp.net应用程序中使用,或者说,我不确定它是否真的会产生新的AppDomain并且工作
• 控制器类型的构造函数和特定实例在代码中是显式的,可以替换为在参数中传递的东西,但是需要处理MarshalByRef /最坏情况的限制,可以使用一些简单的反射来实现它

Answer 2

结束回答我自己的问题:)

public class AspHost : MarshalByRefObject
{
    public string _VirtualDir;
    public string _PhysicalDir;

    public string ViewToString<T>(string aspx, Dictionary<string, object> viewData, T model)
    {
        StringBuilder sb = new StringBuilder();
        using (StringWriter sw = new StringWriter(sb))
        {
            using (HtmlTextWriter tw = new HtmlTextWriter(sw))
            {
                var workerRequest = new SimpleWorkerRequest(aspx, "", tw);
                HttpContext.Current = new HttpContext(workerRequest);

                ViewDataDictionary<T> viewDataDictionary = new ViewDataDictionary<T>(model);
                foreach (KeyValuePair<string, object> pair in viewData)
                {
                    viewDataDictionary.Add(pair.Key, pair.Value);
                }

                object view = BuildManager.CreateInstanceFromVirtualPath(aspx, typeof(object));

                ViewPage viewPage = view as ViewPage;
                if (viewPage != null)
                {
                    viewPage.ViewData = viewDataDictionary;
                }
                else
                {
                    ViewUserControl viewUserControl = view as ViewUserControl;
                    if (viewUserControl != null)
                    {
                        viewPage = new ViewPage();
                        viewPage.Controls.Add(viewUserControl);
                    }
                }

                if (viewPage != null)
                {
                    HttpContext.Current.Server.Execute(viewPage, tw, true);

                    return sb.ToString();
                }

                throw new InvalidOperationException();
            }
        }
    }

    public static AspHost SetupFakeHttpContext(string physicalDir, string virtualDir)
    {
        return (AspHost)ApplicationHost.CreateApplicationHost(
            typeof(AspHost), virtualDir, physicalDir);
    }
}

然后,渲染文件:

var host = AspHost.SetupFakeHttpContext("Path/To/Your/MvcApplication", "/");
var viewData = new ViewDataDictionary<SomeModelType>(){ Model = myModel };
String rendered = host.ViewToString("~/Views/MyView.aspx", new Dictionary<string, object>(viewData), viewData.Model);