I'm having problems proxying metods with parameters using Castle DynamicProxy v1.1.5.0. - I get the exception "Index was outside the bounds of the array."
If I only use methods with no parameters, OR DynamicProxy v2, everything works ok.
Unfortunately, I'm having trouble convincing the leads on my project to add a dependency to v2 (we're already using v1 as it comes with NHibernate).
So my question boils down to: can this be done in v1? Am I using it wrong?
Here's the nitty-gritty.
I've implemented a mechanism that simulates inheritance without having compile-time dependencies to the base class. Pleeease don't ask why, the reasons are ugly :(
Here is a complete example showing how this breaks. I'm referencing Castle.DynamicProxy.dll (v1). If I change the references to Castle.DynamicProxy[b]2[/b].dll (+ Castle.Core.dll), un-comment the #define at the beginning of the code.
Sorry for the long-ish code, but I was afraid I might let out some vital detail...
Also: DISCLAIMER: The code sample has some NASTY bugs! (Probably more than I found, too :)
//#define DynamicProxyV2
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Reflection;
#if DynamicProxyV2
using Castle.Core.Interceptor;
#endif
using Castle.DynamicProxy;
namespace ProxyTest
{
public interface IMyInterface
{
void Foo(object a);
void Bar(object a);
void Baz(object a);
}
public interface IParam
{
string Value { get;}
}
public class DefaultImplementation : IMyInterface{
public virtual void Foo(object a) {
Console.WriteLine("Default Foo");
Bar(null);
}
public virtual void Bar(object a){
Baz(null);
}
public virtual void Baz(object a){
Console.WriteLine("Default Baz");
}
}
class DerivedImpl : ProxyDerivedImplementation {
public DerivedImpl(IMyInterface i_baseImpl)
: base(i_baseImpl) { }
public override void Foo(object a) {
Console.WriteLine("Derived - Foo!");
base.Bar(null);
}
public override void Baz(object a) {
Console.WriteLine("Derived - Baz!");
}
}
public class DoStuff {
[STAThread]
public static void Main()
{
Type t = typeof(DefaultImplementation);
IMyInterface defaultImpl = (IMyInterface)Activator.CreateInstance(t);
DerivedImpl derived = new DerivedImpl(defaultImpl);
derived.Foo(null);
}
}
public class ProxyDerivedImplementation : IMyInterface, IInterceptor {
private IMyInterface m_proxy;
public ProxyDerivedImplementation(IMyInterface i_defaultImplementation)
{
ProxyGenerator pg = new ProxyGenerator();
Type tt = i_defaultImplementation.GetType();
m_proxy = (IMyInterface)pg.CreateClassProxy(tt, this);
}
#if DynamicProxyV2
#region DynProxy v2
public void Intercept(IInvocation invocation) {
try
{
MethodInfo i_method = invocation.Method;
List<Type> types = new List<Type>();
foreach (ParameterInfo info in i_method.GetParameters())
{
types.Add(info.ParameterType);
}
MethodInfo method = this.GetType().GetMethod(i_method.Name, types.ToArray());
object[] attrs = method.GetCustomAttributes(typeof(NotOverridenAttribute), false);
if (attrs.Length > 0)
{
invocation.Proceed();
}
else
{
invocation.ReturnValue = method.Invoke(this, invocation.Arguments);
}
}
catch (Exception ex)
{
Debug.Fail(ex.Message);
//return null;
}
}
#endregion
#else
#region DynProxy v1
public object Intercept(IInvocation i_invocation, params object[] args) {
try {
MethodInfo proxiedMethod = i_invocation.Method;
List<Type> types = new List<Type>();
foreach (ParameterInfo info in proxiedMethod.GetParameters())
{
types.Add(info.ParameterType);
}
//find the corresponding method in the inheritance tree having this class as root
MethodInfo localMethod = this.GetType().GetMethod(proxiedMethod.Name, types.ToArray());
object[] attrs = localMethod.GetCustomAttributes(typeof(NotOverridenAttribute), false);
if (attrs.Length > 0)
{
//it's one of the methods in THIS class, i.e. it's not overridden
//-> we can't call the method in this class, because it will re-trigger this intercept
// and we'd get an infinite loop
// => just dispatch the method to the original proxied type
//
return i_invocation.Proceed();
}
//else we have an override for this method - call it.
return localMethod.Invoke(this, args);
} catch (Exception ex) {
Debug.Fail(ex.Message);
return null;
}
}
#endregion
#endif
[NotOverriden]
public virtual void Foo(object a) { m_proxy.Foo(a); }
[NotOverriden]
public virtual void Bar(object a) { m_proxy.Bar(a); }
[NotOverriden]
public virtual void Baz(object a) { m_proxy.Baz(a); }
}
class NotOverridenAttribute : Attribute { }
}
Whew! That's a mouthful. Here's the exception that occurs when using v1:
{"Index was outside the bounds of the array."}
[System.IndexOutOfRangeException]: {"Index was outside the bounds of the array."}
Data: {System.Collections.ListDictionaryInternal}
HelpLink: null
InnerException: null
Message: "Index was outside the bounds of the array."
Source: "DynamicAssemblyProxyGen"
StackTrace: " at CProxyTypeDefaultImplementationProxyTest0.__delegate_2.Call(Object[] )\r\n at Castle.DynamicProxy.Invocation.AbstractInvocation.Proceed(Object[] args)\r\n at ProxyTest.ProxyDerivedImplementation.Intercept(IInvocation i_invocation, Object[] args) in D:\\My Documents\\Visual Studio 2005\\Projects\\DefaultImpl\\AddedValue\\AddedValue.cs:line 133"
TargetSite: {System.Object Call(System.Object[])}
When running with v2, all I get is the correct output:
Derived - Foo! Derived - Baz!
...Help?
