public class MyInterceptor : IInterceptor<MyType>
{
public void InterceptGetter(IProxy proxy, MyType @object, string propertyName, out object value)
{
// do something before get
proxy.ProceedGetter(propertyName, out value);
// do something after get
}
public void InterceptSetter(IProxy proxy, MyType @object, string propertyName, object value)
{
// do something before set
proxy.ProceedSetter(propertyName, value);
// do something after set
m_setterCalled = true;
}
private bool m_setterCalled = false;
public bool SetterWasCalled
{
get { return m_setterCalled; }
}
}
public class MyType
{
public virtual string Property { get; set; }
}
/////// AUTOGENERATED PROXY ///////
public class MyTypeProxy : MyType, IProxy
{
private MyType m_object;
private IInterceptor<MyType> m_interceptor;
public MyTypeProxy(MyType @object, IInterceptor<MyType> interceptor)
{
m_object = @object;
m_interceptor = interceptor;
}
public override string Property
{
get
{
object value;
m_interceptor.InterceptGetter(this, m_object, "Property", out value);
return (string)value;
}
set { m_interceptor.InterceptSetter(this, m_object, "Property", value); }
}
public void ProceedGetter(string propertyName, out object value)
{
if (propertyName == "Property")
{
value = m_object.Property;
}
else
{
throw new MissingMemberException
();
}
}
public void ProceedSetter(string propertyName, object value)
{
if (propertyName == "Property")
{
m_object.Property = (string)value;
}
else
{
throw new MissingMemberException
();
}
}
}
/////// SUPPORTING CODE ///////
public interface IProxy
{
void ProceedGetter(string propertyName, out object value);
void ProceedSetter(string propertyName, object value);
}
public interface IInterceptor<T>
{
void InterceptGetter(IProxy proxy, T @object, string propertyName, out object value);
void InterceptSetter(IProxy proxy, T @object, string propertyName, object value);
}
/////// TEST ///////
public static class Test
{
public static void ProxyTest()
{
var myType =
new MyType
();
myType.Property = "Test";
var interceptor =
new MyInterceptor
();
MyType wrappedMyType = GenerateProxy(myType, interceptor);
wrappedMyType.Property = "Test2";
Debug.Assert(myType.Property == "Test2");
Debug.Assert(interceptor.SetterWasCalled);
}
// This method belongs in a proxy generator
private static MyType GenerateProxy(MyType myType, IInterceptor<MyType> interceptor)
{
return new MyTypeProxy
(myType, interceptor
);
}
}
a couple of month back. And I just love going back to it and reading chapters again and again. One of the most interesting phrases used in the book is "Coding Smell". And it is way easier to 
