You are creating an application that consumes a Windows Communication Foundation (WCF) service. The service implements the IService contract. The client application contains the CallbackHandler class, which implements IServiceCallback.You need to ensure that a client proxy is created that can communicate with the service over a duplex channel.
Which code segment should you use?（）

单项选择题You are creating a Windows Communication Foundation (WCF) service that uses claims-based authorization. The following code retrieves the correct claim set.var claims = ServiceSecurityContext.Current.AuthorizationContext.ClaimSets[0];You need to validate that the requesting client application has included a valid DNS value in the claim. Which code segment should you use to retrieve the claim for validation?（）

A. claims.FindClaims(ClaimTypes.Dns, Rights.PossessProperty).FirstOrDefault();
B. claims.FindClaims(ClaimTypes.Dns, Rights.Identity).FirstOrDefault();
C. claims.ContainsClaim(Claim.CreateDnsClaim(ClaimTypes.Dns));
D. claims.Equals(ClaimTypes.Dns);

单项选择题You create a Windows Communication Foundation (WCF) service. It is deployed on Microsoft Internet Information Services (IIS) with an application pool running as Network Service. You enable WMI tracing before launching the service. Your IT support staff adds WMI data collection through ASP.NET WMI tracing.You need to restrict the collection of WMI data to a privileged account. What should you do in WMI Control in the Computer Management console?（）

A.
B.
C.
D.

单项选择题You are developing a Windows Communication Foundation (WCF) service that does not operate on a duplex channel.You find that operations do not start until all previous operations have finished. The service hosting code contains the following lines.var service = new WarehouseService(); var host = new ServiceHost(service);You need to ensure that new operations do not wait for previous operations to finish. Which attribute should you use to decorate the service?（）

A. [ServiceBehavior(InstanceContextMode=InstanceContextMode.Single, ConcurrencyMode=ConcurrencyMode.Multiple)]
B. [CallbackBehavior(ConcurrencyMode=ConcurrencyMode.Multiple)]
C. [ServiceBehavior(InstanceContextMode=InstanceContextMode.Single, ConcurrencyMode=ConcurrencyMode.Single)]
D. [ServiceBehavior(InstanceContextMode=InstanceContextMode.Single, ConcurrencyMode=ConcurrencyMode.Reentrant)]

单项选择题You are developing a Windows Communication Foundation (WCF) service that allows customers to update financial data. The client applications call the service in a transaction. The service contract is defined as follows. (Line numbers are included for reference only.) 01 [ServiceContract] 02 public interface IDataUpdate 03 { 04 [OperationContract] 05 [TransactionFlow(TransactionFlowOption.Mandatory)] 06 void Update(string accountNumber, double amount); 07 } 08 09 ... 10 class UpdateService : IDataUpdate 11 { 12 [OperationBehavior(TransactionScopeRequired = true, TransactionAutoComplete = true)]13 public void Update(string accountNumber, double amount) 14 { 15 try 16 { 17 ... 18 } 19 catch(Exception ex) 20 { 21 WriteErrorLog(ex); 22 ... 23 } 24 } 25 } 26Customers report that the transaction completes successfully even if the Update method throws an exception.You need to ensure that the transaction is aborted if the Update method is not successful. What should you do? （）

A. Insert the following line at line 22: throw;
B. Insert the following line at line 09: [ServiceBehavior(TransactionAutoCompleteOnSessionClose=false)]
C. Replace line 12 with the following line: [OperationBehavior(TransactionScopeRequired=true, TransactionAutoComplete= false)]
D. Insert the following line at line 09.: [ServiceBehavior(TransactionAutoCompleteOnSessionClose=true)]

单项选择题You are developing a Windows Communication Foundation (WCF) service that must be discoverable.You need to ensure that the ServiceHost instance supports multiple discovery versions. What should you do?（）

A. - Specify a unique DiscoveryVersion parameter for each endpoint constructor. - Use the same value for the Address property of each endpoint.
B. - Use the endpoint constructor without the DiscoveryVersion parameter. - Use a unique value for the Address property of each endpoint.
C. - Specify a unique DiscoveryVersion parameter for each endpoint constructor. - Use a unique value for the Address property of each endpoint.
D. - Use the endpoint constructor without the DiscoveryVersion parameter. - Use the same value for the Address property of each endpoint.