I created an ASP.NET app containing a WCF Data Service using Visual Studio 2015, based on the AdventureWorks2014 OLTP, by following this walkthrough.
When I build the app and run it in a debugger (on IIS Express), the service loads fine and I see the XML metadata displayed in my browser, and can make further requests to subpaths to view the rows of my database. I can continue to make such requests as long as the debugging session continues.
As soon as I stop the debugger and start it again, without a rebuild in between, my browser instead displays an error:
The type 'AdventureWorks.Internal.WebService.DataService', provided as the Service attribute value in the ServiceHost directive, or provided in the configuration element system.serviceModel/serviceHostingEnvironment/serviceActivations could not be found.
[InvalidOperationException: The type 'AdventureWorks.Internal.WebService.DataService', provided as the Service attribute value in the ServiceHost directive, or provided in the configuration element system.serviceModel/serviceHostingEnvironment/serviceActivations could not be found.]
System.ServiceModel.Activation.ServiceHostFactory.CreateServiceHost(String constructorString, Uri[] baseAddresses) +741
System.ServiceModel.HostingManager.CreateService(String normalizedVirtualPath, EventTraceActivity eventTraceActivity) +1417
System.ServiceModel.HostingManager.ActivateService(ServiceActivationInfo serviceActivationInfo, EventTraceActivity eventTraceActivity) +53
System.ServiceModel.HostingManager.EnsureServiceAvailable(String normalizedVirtualPath, EventTraceActivity eventTraceActivity) +660
[ServiceActivationException: The service '/DataService.svc' cannot be activated due to an exception during compilation. The exception message is: The type 'AdventureWorks.Internal.WebService.DataService', provided as the Service attribute value in the ServiceHost directive, or provided in the configuration element system.serviceModel/serviceHostingEnvironment/serviceActivations could not be found..]
System.Runtime.AsyncResult.End(IAsyncResult result) +386
System.ServiceModel.Activation.HostedHttpRequestAsyncResult.End(IAsyncResult result) +174
System.ServiceModel.Activation.ServiceHttpHandler.EndProcessRequest(IAsyncResult result) +7
System.Web.CallHandlerExecutionStep.OnAsyncHandlerCompletion(IAsyncResult ar) +129
This happens when I develop either in Visual Studio 2015 or 2017. I'm using Windows 10 with my ASP.NET app targeting .NET Framework 4.6.1.
DataService.svc:
<%@ ServiceHost Language="C#" Factory="System.ServiceModel.Activation.WebServiceHostFactory, System.ServiceModel.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" Service="AdventureWorks.Internal.WebService.DataService" %>
DataService.svc.cs:
namespace AdventureWorks.Internal.WebService
{
//[ServiceBehavior(IncludeExceptionDetailInFaults = true)]
public class DataService : DataService<AdventureWorksDatabaseEntities>
{
// This method is called only once to initialize service-wide policies.
public static void InitializeService(DataServiceConfiguration config)
{
config.SetEntitySetAccessRule("*", EntitySetRights.All);
config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V3;
}
}
}
Web.config:
<?xml version="1.0" encoding="utf-8"?>
<!--
For more information on how to configure your ASP.NET application, please visit
http://go.microsoft.com/fwlink/?LinkId=169433
-->
<configuration>
<configSections>
<!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
<section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
</configSections>
<system.web>
<compilation debug="true" targetFramework="4.6.1" />
<httpRuntime targetFramework="4.6.1" />
<httpModules>
<add name="ApplicationInsightsWebTracking" type="Microsoft.ApplicationInsights.Web.ApplicationInsightsHttpModule, Microsoft.AI.Web" />
</httpModules>
</system.web>
<system.codedom>
<compilers>
<compiler language="c#;cs;csharp" extension=".cs" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.CSharpCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:6 /nowarn:1659;1699;1701" />
<compiler language="vb;vbs;visualbasic;vbscript" extension=".vb" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.VBCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:14 /nowarn:41008 /define:_MYTYPE=\"Web\" /optionInfer+" />
</compilers>
</system.codedom>
<system.webServer>
<validation validateIntegratedModeConfiguration="false" />
<modules>
<remove name="ApplicationInsightsWebTracking" />
<add name="ApplicationInsightsWebTracking" type="Microsoft.ApplicationInsights.Web.ApplicationInsightsHttpModule, Microsoft.AI.Web" preCondition="managedHandler" />
</modules>
</system.webServer>
<connectionStrings>
<add name="AdventureWorksDatabaseEntities" connectionString="metadata=res://*/DataModel.csdl|res://*/DataModel.ssdl|res://*/DataModel.msl;provider=System.Data.SqlClient;provider connection string="data source=(LocalDB)\MSSQLLocalDB;attachdbfilename=|DataDirectory|\AdventureWorksDatabase.mdf;integrated security=True;connect timeout=30;MultipleActiveResultSets=True;App=EntityFramework"" providerName="System.Data.EntityClient" />
</connectionStrings>
<entityFramework>
<defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">
<parameters>
<parameter value="v13.0" />
</parameters>
</defaultConnectionFactory>
</entityFramework>
<system.serviceModel>
<serviceHostingEnvironment aspNetCompatibilityEnabled="true" />
</system.serviceModel>
</configuration>
This error occurs due to namespace inconsistencies. please check all the namespaces. it should work.