Question

我正在使用ApplicationEventHanlder在应用程序启动后创建内容。这是我的代码

public class CreateContent : ApplicationEventHandler
{
    protected override void ApplicationStarted(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext)
    {
        var root = applicationContext.Services.ContentService.GetRootContent();

        var content = applicationContext.Services.ContentService.CreateContent("Profile", -1, "umbTextPage");

        applicationContext.Services.ContentService.Save(content);

        base.ApplicationStarted(umbracoApplication, applicationContext);
    }
}

[NullReferenceException: Object reference not set to an instance of an object.]
   Umbraco.Core.Security.AuthenticationExtensions.GetCurrentIdentity(HttpContextBase http, Boolean authenticateRequestIfNotFound) +127
   Umbraco.Web.Security.WebSecurity.GetUserId() +55
   Umbraco.Web.Security.WebSecurity.get_CurrentUser() +63
   Umbraco.Web.NotificationServiceExtensions.SendNotification(INotificationService service, IUmbracoEntity entity, IAction action, UmbracoContext umbracoContext, ApplicationContext applicationContext) +221
   Umbraco.Web.NotificationServiceExtensions.SendNotification(INotificationService service, IUmbracoEntity entity, IAction action, UmbracoContext umbracoContext) +118
   Umbraco.Web.NotificationServiceExtensions.SendNotification(INotificationService service, IUmbracoEntity entity, IAction action, ApplicationContext applicationContext) +111
   Umbraco.Web.Strategies.c__DisplayClass7.b__2(IContentService sender, SaveEventArgs`1 args) +219
   Umbraco.Core.Events.TypedEventHandler`2.Invoke(TSender sender, TEventArgs e) +0
   Umbraco.Core.Events.EventExtensions.RaiseEvent(TypedEventHandler`2 eventHandler, TArgs args, TSender sender) +48
   Umbraco.Core.Services.ContentService.Save(IContent content, Boolean changeState, Int32 userId, Boolean raiseEvents) +632
   Umbraco.Core.Services.ContentService.Save(IContent content, Int32 userId, Boolean raiseEvents) +47
   MyUmbraco.CreateContent.ApplicationStarted(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext) in c:\Users\duongdd\Documents\Visual Studio 2013\Projects\MyUmbraco\MyUmbraco\CreateContent.cs:19
   Umbraco.Core.ApplicationEventHandler.OnApplicationStarted(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext) +62
   Umbraco.Core.CoreBootManager.b__5(IApplicationEventHandler x) +79
   Umbraco.Core.EnumerableExtensions.ForEach(IEnumerable`1 items, Action`1 action) +204
   Umbraco.Core.CoreBootManager.Complete(Action`1 afterComplete) +185
   Umbraco.Web.WebBootManager.Complete(Action`1 afterComplete) +74
   Umbraco.Core.UmbracoApplicationBase.StartApplication(Object sender, EventArgs e) +242
   Umbraco.Core.UmbracoApplicationBase.Application_Start(Object sender, EventArgs e) +40

[HttpException (0x80004005): Object reference not set to an instance of an object.]
   System.Web.HttpApplicationFactory.EnsureAppStartCalledForIntegratedMode(HttpContext context, HttpApplication app) +572
   System.Web.HttpApplication.RegisterEventSubscriptionsWithIIS(IntPtr appContext, HttpContext context, MethodInfo[] handlers) +178
   System.Web.HttpApplication.InitSpecial(HttpApplicationState state, MethodInfo[] handlers, IntPtr appContext, HttpContext context) +218
   System.Web.HttpApplicationFactory.GetSpecialApplicationInstance(IntPtr appContext, HttpContext context) +369
   System.Web.HttpApplicationFactory.GetPipelineApplicationInstance(IntPtr appContext, HttpContext context) +102
   System.Web.Hosting.PipelineRuntime.InitializeApplication(IntPtr appContext) +275

[HttpException (0x80004005): Object reference not set to an instance of an object.]
   System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +761
   System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +150
   System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +245

是否有人与此错误相似并为我提供解决方案？

谢谢！

Answer 1

看起来这个问题已经得到修复 - 至少部分是：https://github.com/umbraco/Umbraco-CMS/commit/ac88da4188365b101debf0f3e9ad7ec7c300a898用于即将发布的7.1.3补丁版本。

我说部分是因为我认为这里有两个问题：

您发布的例外情况是在CurrentUser周围，但不会发生使用API时存在。这个问题尚未解决。
用于发送通知的NotificationService需要一个HttpContext，因为它涉及一些遗留代码。这在上面的提交中已得到修复，因此如果HttpContext不可用，则不会发送通知。

但幸运的是，在您提供的代码示例中有一种解决方法。 ContentService中的Save-method有一个重载，用于指定该方法不应引发事件。当您不为Save方法引发事件时，NotificationService将无法被调用，并且异常不会发生。但当然，这也意味着不会使用API从代码中为您创建的内容项目发送通知。

示例：

public class CreateContent : ApplicationEventHandler
{
    protected override void ApplicationStarted(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext)
    {
        var root = applicationContext.Services.ContentService.GetRootContent();

        var content = applicationContext.Services.ContentService.CreateContent("Profile", -1, "umbTextPage");

        applicationContext.Services.ContentService.Save(content, 0, false);

        base.ApplicationStarted(umbracoApplication, applicationContext);
    }
}

请注意applicationContext.Services.ContentService.Save(content, 0, false);包含两个额外的参数：0表示用户ID（零通常是始终存在的admin用户），false表示raiseEvents = false。

使用此方法应确保您的代码不会调用NotificationService，然后会抛出异常。

希望这有帮助！

Umbraco - 尝试使用ContentService保存内容时出错

1 个答案: