OperationBehavior Attribute And Its Parameters In WCF

This blog is a brief introduction to the OperationBehavior attribute and parameters, which can be used with this attribute.

OperationBehavior Attribute

OperationBehavior attribute is used to specify the execution behavior of a service operation and placed on the method of service implementation class. Like ServiceBehavior attribute (see ServiceBehavior Attribute for detail), this attribute is also optional.

Example

[ServiceContract]
public interface IServiceClass {
    [OperationContract]
    int Square(int number);
}
[ServiceBehavior]
public class ServiceClass: IServiceClass {
    [OperationBehavior]
    public int Square(int number) {
        return number * number;
    }
}

OperationBehavior attribute parameters

OperationBehavior attribute contains parameters that specify additional information about OperationBehavior attribute. The name of these parameters and their functions are given below.

AutoDisposeParameters

This parameter is used to specify whether the service will dispose parameters of associated methods automatically or cache them. This parameter is of bool type and its false value indicates that service will cache the parameter resources.

Example

[OperationBehavior(AutoDisposeParameters = true)]
public void Square(int number) {
    result = number * number;
}

The default value for this property is true.

Impersonation

This parameter specifies the impersonation behavior for a service operation. This parameter lets you specify  the method which is to be executed under the impersonated caller’s identity. The value for this parameter can be set by following ImpersonationOption enumerations values

 

ImpersonationOption enumerations values	Brief Description
Allowed	Impersonation will be performed if credentials are available
NotAllowed	Impersonation will not be performed
Required	Impersonation is required.

If Impersonation is set to either Allowed or Required than a binding must also be used that supports impersonation. Its default value is NotAllowed

Example 

[OperationBehavior(Impersonation = ImpersonationOption.Allowed)]
public void Square(int number) {
    result = number * number;
}

ReleaseInstanceMode

This parameter is used to determine the recycle point of the service object during the course of an operation. The default behavior of this parameter is according to the InstanceContextMode parameter value of [ServiceContract] attribute. The value of this parameter can be set from the following ReleaseInstanceMode enumeration values

ReleaseInstanceMode enumeration values	Brief Description
AfterCall	Recycles the object after the operation has completed
BeforeAndAfterCall	Recycles the object before calling the operation and after operation completion
BeforeCall	Recycles the object before calling the operation
None	Recycles the object according to the InstanceContextMode

Example 

[OperationBehavior(ReleaseInstanceMode = ReleaseInstanceMode.AfterCall)]
public void Square(int number) {
    result = number * number;
}

The default value for this parameter is None.

TransactionAutoComplete

This parameter specify whether to complete current transaction automatically or cancelled in case if exceptions are found.

Example 

[OperationBehavior(TransactionAutoComplete = true)]
public void Square(int number) {
    result = number * number;
}

TransactionScopeRequired

This parameter specifies whether the associated method requires a transaction scope. In case of flowed transaction (a transaction in which transaction id is passed over the wire and used on the receiving side to perform some task), the method will execute within that transaction, otherwise a new transaction is created and used for that method execution.

Example 

[OperationBehavior(TransactionScopeRequired = true)]
public void Square(int number) {
    result = number * number;
}