Ah, I just saw in your later message that you want a method pointer (i.e. a delegate) which magically instantiates the target method when you supply a type argument.
yep That can be emulated via the MethodInfo approach described in the previous paragraph. With a bit of moderately clever design, you could create set of related reusable generic types, all with different arity of their Invoke methods, that solves this problem in a totally general way. Boooo.....I just need it the once....I can see how one would do it 'long hand'. I was hoping that I was just ignorant of some minor syntactical thing. Thanks anyway.... -----Original Message----- From: Discussion of advanced .NET topics. [mailto:[EMAIL PROTECTED] On Behalf Of Barry Kelly Sent: 30 March 2007 17:35 To: ADVANCED-DOTNET@DISCUSS.DEVELOP.COM Subject: Re: [ADVANCED-DOTNET] delegate to genetic method.... Mark Nicholls <[EMAIL PROTECTED]> wrote: > class Bar > { > int Foo<X>(X x); > } > > how do I define a single delegate that can refer to Foo? > > delegate int FooDelegate<X>(X x); Sure, that'll work: ---8<--- using System; class App { int Foo<X>(X x) { return 0; } delegate int FooDelegate<X>(X x); void P<T>() { FooDelegate<T> f = Foo<T>; // works just fine } static void Main(string[] args) { } } --->8--- What you can't do is create a delegate to an uninstantiated generic method in non-generic code - for one thing, what would the type of the delegate be? How could you call it, when it expects a value of type X, and you've got no way of specifying the type X for a normal delegate? FooDelegate f = Foo<>; f(???) If you want to be able to pass around something which can be called, and resolved (i.e. type arguments bound) later, try getting the MethodInfo for Bar.Foo<>, and passing that around instead. You can call MethodInfo.MakeGenericMethod to supply the type arguments, and use Delegate.CreateDelegate to turn it into something that's more efficiently callable than via reflection. Ah, I just saw in your later message that you want a method pointer (i.e. a delegate) which magically instantiates the target method when you supply a type argument. That can be emulated via the MethodInfo approach described in the previous paragraph. With a bit of moderately clever design, you could create set of related reusable generic types, all with different arity of their Invoke methods, that solves this problem in a totally general way. -- Barry -- http://barrkel.blogspot.com/ =================================== This list is hosted by DevelopMentor(r) http://www.develop.com View archives and manage your subscription(s) at http://discuss.develop.com =================================== This list is hosted by DevelopMentor® http://www.develop.com View archives and manage your subscription(s) at http://discuss.develop.com
