Issue intercepting property in Silverlight application
- by joblot
I am using Ninject as DI container in a Silverlight application. Now I am extending the application to support interception and started integrating DynamicProxy2 extension for Ninject. I am trying to intercept call to properties on a ViewModel and ending up getting following exception:
“Attempt to access the method failed: System.Reflection.Emit.DynamicMethod..ctor(System.String, System.Type, System.Type[], System.Reflection.Module, Boolean)”
This exception is thrown when invocation.Proceed() method is called. I tried two implementations of the interceptor and they both fail
public class NotifyPropertyChangedInterceptor: SimpleInterceptor
{
protected override void AfterInvoke(IInvocation invocation)
{
var model = (IAutoNotifyPropertyChanged)invocation.Request.Proxy;
model.OnPropertyChanged(invocation.Request.Method.Name.Substring("set_".Length));
}
}
public class NotifyPropertyChangedInterceptor: IInterceptor
{
public void Intercept(IInvocation invocation)
{
invocation.Proceed();
var model = (IAutoNotifyPropertyChanged)invocation.Request.Proxy;
model.OnPropertyChanged(invocation.Request.Method.Name.Substring("set_".Length));
}
}
I want to call OnPropertyChanged method on the ViewModel when property value is set.
I am using Attribute based interception.
[AttributeUsage(AttributeTargets.Property, AllowMultiple = false, Inherited = true)]
public class NotifyPropertyChangedAttribute : InterceptAttribute
{
public override IInterceptor CreateInterceptor(IProxyRequest request)
{
if(request.Method.Name.StartsWith("set_"))
return request.Context.Kernel.Get<NotifyPropertyChangedInterceptor>();
return null;
}
}
I tested the implementation with a Console Application and it works alright.
I also noted in Console Application as long as I had Ninject.Extensions.Interception.DynamicProxy2.dll in same folder as Ninject.dll I did not have to explicitly load DynamicProxy2Module into the Kernel, where as I had to explicitly load it for Silverlight application as follows:
IKernel kernel = new StandardKernel(new DIModules(), new DynamicProxy2Module());
Could someone please help? Thanks
