Using the Create Method

To create a new configured instance of an interceptable target class, the developer calls the static Create method of the Policy Injection Application Block factory class named PolicyInjection.

If the application block determines that the configuration specifies handlers for a method or property of the specified target class, it does the following:

• It creates an instance of the target class.
• It creates a suitable proxy for the class or for the specified interface that the class implements.
• It wires up the specified handlers into a pipeline between the relevant methods and properties of the proxy and the concrete target class instance.
• It returns a reference to the proxy.

If the application block determines that the configuration or target class attributes do not specify any matching handlers, the Create method just returns a new instance of the target class.

Target Classes That Inherit from MarshalByRefObject

For a target class that inherits from MarshalByRefObject, client code uses the .NET Framework generic code syntax to specify the class name and any parameters that the target class constructor requires. The Create method returns an instance of a policy-enabled proxy through which client code can access that class, as shown in the following code.

TargetClass theTarget 
    = PolicyInjection.Create<TargetClass>(parameter1, parameter2);

Dim theTarget As TargetClass _
    = PolicyInjection.Create(Of TargetClass)(parameter1, parameter2)

Target Classes That Implement an Interface

For a target class that implements an interface, client code can use the .NET Framework generic code syntax to specify the implementing class name, the interface name, and any parameters that this target class constructor requires. The Create method returns an instance of a policy-enabled proxy through which client code can access the target class that implements the specified interface type, as shown in the following code.

ITargetInterface theTarget = PolicyInjection.Create<TargetClass,
                               ITargetInterface>(parameter1, parameter2);

Dim theTarget As ITargetInterface
theTarget = PolicyInjection.Create(Of TargetClass, ITargetInterface) _
                                        (parameter1, parameter2)