异常“项目已被添加。”在MetaModel.Register

Question

我的Global.asax包含下面的代码，

public class Global : System.Web.HttpApplication 
    { 
     private MetaModel _s_Model = new AdvancedMetaModel(); 
     public MetaModel s_Model 
     { 
      get 
      { 
       return _s_Model; 
      } 
     } 

     private MetaModel _a_Model = new AdvancedMetaModel(); 
     public MetaModel a_Model 
     { 
      get 
      { 
       return _a_Model; 
      } 
     } 

     public void RegisterRoutes(RouteCollection routes) 
     { 
      Dictionary<Helper.ModelName, MetaModel> registeredRoutes = new Dictionary<Helper.ModelName, MetaModel>(); 

      if (SQLAppModel.ModelQuery.GetUserType() == Utility.Helper.UserType.ApplicationAdmin 
       || SQLAppModel.ModelQuery.GetUserType() == Utility.Helper.UserType.SystemAdmin) 
      { 
       _a_Model.RegisterContext(typeof(SQLAppModel.aEntities), new ContextConfiguration() { ScaffoldAllTables = true }); 

       /** Full Permission **/ 
       routes.Add(new DynamicDataRoute("{table}/ListDetails.aspx") 
       { 
        Action = PageAction.List, 
        ViewName = "ListDetails", 
        Model = a_Model 
       }); 

       routes.Add(new DynamicDataRoute("{table}/ListDetails.aspx") 
       { 
        Action = PageAction.Details, 
        ViewName = "ListDetails", 
        Model = a_Model 
       }); 

       registeredRoutes.Add(Helper.ModelName.Administration, a_Model); 
      } 

      string supportedEnvironments = System.Configuration.ConfigurationManager.AppSettings[Helper.SupportedEnvironmentsAppSettingsKey].ToString(); 

      foreach (string supportedEnvironment in supportedEnvironments.Split(',')) 
      { 

       foreach (var supportedSystem in SQLAppModel.ModelQuery.GetSupportedSystems(supportedEnvironment, true)) 
       { 
        if (supportedEnvironment.ToUpper() == "ORACLE") 
        { 
         if (supportedSystem.Name.ToUpper() == "ADS") 
         { 
          _s_model.RegisterContext(typeof(OracleAppModel.sEntities), new ContextConfiguration() 
          { 
           ScaffoldAllTables = true 
          }); 

          routes.Add(new DynamicDataRoute("{table}/ReadOnlyListDetails.aspx") 
          { 
           Action = PageAction.List, 
           ViewName = "ReadOnlyListDetails", 
           Model = s_model 
          }); 

          routes.Add(new DynamicDataRoute("{table}/ReadOnlyListDetails.aspx") 
          { 
           Action = PageAction.Details, 
           ViewName = "ReadOnlyListDetails", 
           Model = s_model 
          }); 
          registeredRoutes.Add(Helper.ModelName.ADS, s_model); 
         } 
        } 
       } 

      HttpContext.Current.Session[Helper.RegisteredRouteListSessionKey] = registeredRoutes; 
     } 

     void Application_Start(object sender, EventArgs e) 
     { 

     } 

     void Session_Start(object sender, EventArgs e) 
     { 
      SQLAppModel.ModelQuery.GetApplicationUser(); 
      RegisterRoutes(RouteTable.Routes); 
     } 
    } 

当调试我用ASP.NET开发的Web服务器应用程序的第一次，应用程序工作正常，并给出了期望的结果。

但是当我停止了调试，并重新启动它，它提供了以下异常，

项目已添加。键在字典： 'APP.SQLAppModel.sEntities' 键被加入： 'APP.SQLAppModel.sEntities'

线抛出该异常是_a_Model.RegisterContext（typeof运算（SQLAppModel.aEntities），新ContextConfiguration（）{ScaffoldAllTables = true}）;

完整的堆栈跟踪：

[ArgumentException的：项目已添加。键入字典：'APP.SQLAppModel.sEntities'键被添加：'APP.SQLAppModel.sEntities'] System.Collections.Hashtable.Insert（Object key，Object nvalue，Boolean add）+9352427 System.Collections.Hashtable。添加（对象键，对象值）+11 System.Web.DynamicData.MetaModelManager.AddModel（类型contextType，MetaModel模型）+96 System.Web.DynamicData.MetaModel.RegisterContext（DataModelProvider dataModelProvider，ContextConfiguration配置）+727 System .Web.DynamicData.MetaModel.RegisterContext（Func`1 contextFactory，ContextConfiguration配置）+390 System.Web.DynamicData.MetaModel.RegisterContext（Type contextType，ContextConfiguration配置）+88 SAMI.Global.RegisterRoutes（RouteCollection routes）in C ：\ Anand \ SAMI \ SAMI \ SAMI \ Global.asax.cs：42 C：\ Anand \ SAMI \ SAMI \ SAMI \ Global.asax.cs中的SAMI.Global.Session_Start（对象发件人，EventArgs e）：137 System.Web.SessionState.SessionStateModule.RaiseOnStart（EventArgs e）+8955827 System .Web.SessionState.SessionStateModule.CompleteAcquireState（）+148 System.Web.SessionState.SessionStateModule.BeginAcquireState（Object source，EventArgs e，AsyncCallback cb，Object extraData）+561 System.Web.AsyncEventExecutionStep.System.Web.HttpApplication。 IExecutionStep.Execute（）+96 System.Web.HttpApplication.ExecuteStep（IExecutionStep一步，布尔& completedSynchronously）184

请让我知道如何解决这个问题。我很难确定问题。

Answer 1

问题是你从Session_Start调用RegisterRoutes，所以它可以被多次调用。您需要从Application_Start调用它。