Code inspection: One way operations must not return values

This inspection reports violations of the IsOneWay=true contract in the System.ServiceModel.OperationContract context.

The IsOneWay=true contract is used in Windows Communication Foundation (WCF) to indicate that an operation should be invoked in a fire-and-forget manner, which means that the client does not wait for a response from the server after invoking the operation.

If a non-void method is annotated this way, you have an inconsistency that might indicate an error.

There are two ways to fix that:

If your intention is to receive a response from the service, remove the IsOneWay=true contract:

            
[OperationContract(IsOneWay=true)]
public string GetString()
{
    return "something";
}
    
        

            
[OperationContract]
public string GetString()
{
    return "something";
}
    
        

If you intend to keep the one-way operation behavior and don't need the return value, modify the method to return void instead:

            
[OperationContract(IsOneWay=true)]
public string GetString()
{
    return "something";
}
    
        

            
[OperationContract(IsOneWay=true)
public void GetString()
{
    /*Do something*/
}
    
        

Last modified: 08 April 2024