I am receiving a FaultException from a WCF service as follows when it is invoked:
2012-04-02 16:26:00.3593|Error|System.ServiceModel.FaultException`1[System.ServiceModel.ExceptionDetail]: The type initializer for 'vService.CheckService' threw an exception. (Fault Detail is equal to An ExceptionDetail, likely created by IncludeExceptionDetailInFaults=true, whose value is:
System.TypeInitializationException: The type initializer for 'vService.CheckService' threw an exception. ----> System.NullReferenceException: Object reference not set to an instance of an object.
at vService.CheckService..cctor() in d:\working\code\VioletServer\vService\CheckService.cs:line 14
--- End of inner ExceptionDetail stack trace ---
at vService.CheckService..ctor()
at CreatevService.CheckService()
at System.ServiceModel.Dispatcher.InstanceProvider.GetInstance(InstanceContext instanceContext, Message message)
at System.ServiceModel.Dispatcher.InstanceBehavior.GetInstance(InstanceContext instanceContext, Message request)
at System.ServiceModel.InstanceContext.GetServiceInstance(Message message)
at System.ServiceModel.Dispatcher.InstanceBehavior.EnsureServiceInstance(MessageRpc& rpc)
at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage41(MessageRpc& rpc)
...).
Line 14 of CheckService.cs is
private static string connStr = ConfigurationManager.ConnectionStrings["violetdb"].ConnectionString;
What does the exception mean in this context and how can I resolve it?
//CheckService.cs
public class CheckService : ICheckService
{
private static string connStr = ConfigurationManager.ConnectionStrings["violetdb"].ConnectionString;
MessageRepository _repo = new MessageRepository(connStr);
public CheckService(){}
public CheckService(MessageRepository repo)
{
_repo = repo;
}
public void SendMessage(string sender, string recipient, string messagetext)
{
_repo.DeliverMessage(sender,recipient,messagetext);
}
}
Most likely your WCF service does not have a connection string named "violetdb" in its application configuration file.
A TypeInitializerException
is thrown in this circumstance, because you have a static
field which is being initialised ahead of type construction, and because the ConnectionStrings["violetdb"]
call is returning null
, and it is throwing an NullReferenceException
.
Bottom line, check the <connectionStrings>
section of your configuration file and ensure that the connection string exists.