silly question.
the machine where this does not work....is framework 2.0 installed? -----Original Message----- From: Discussion of advanced .NET topics. [mailto:[EMAIL PROTECTED] Behalf Of Brad Wilson Sent: Monday, July 23, 2007 12:43 PM To: ADVANCED-DOTNET@DISCUSS.DEVELOP.COM Subject: Re: [ADVANCED-DOTNET] What's wrong with typeof(GenericClass<>) for Reflection Emit? FWIW, using typeof(System.Collections.Generic.List<>) yields the same error. On 7/23/07, Brad Wilson <[EMAIL PROTECTED]> wrote: > > I'm using AssemblyBuilder and friends to emit a wrapper class that derives > from a given type. When provided with typeof(NonGenericClass), it works > great. However, when it is provided with typeof(GenericClass<>), it fails to > find that type at the final stages of the emit: > > System.TypeLoadException was unhandled > Message="Could not load type 'GenericClass`1' from assembly 'Example, > Version= 0.0.0.0, Culture=neutral, PublicKeyToken=null'." > Source="mscorlib" > TypeName="GenericClass`1" > StackTrace: > at System.Reflection.Emit.TypeBuilder.TermCreateClass(Int32 handle, > Module module) > at System.Reflection.Emit.TypeBuilder.CreateTypeNoLock() > at System.Reflection.Emit.TypeBuilder.CreateType() > at Program.WrapType(Type typeToWrap) in Program.cs:line 46 > at Program.Main() in Program.cs:line 15 > > The problem is, "Example" is the name of the dynamic assembly module, not > the name of the EXE where GenericClass<> is found. I believe it's looking in > the wrong place to find the generic type, even though we pass a Type object > to DefineType(). > > The code is pretty straight-forward Reflection Emit code, which I have > narrowed down to the smallest amount of code necessary to repro (attached > below). > > Thoughts? Why does this work for non-generics and not for generics? > > - Brad > > P.S. Just to complicate matters, this code works on the machine we > developed it on, but no others. We can't figure out exactly what the > difference between that machine and any others is. > > -------- Repro Code -------- > > using System; > using System.Reflection ; > using System.Reflection.Emit; > using System.Threading; > > public class NonGenericClass {} > > public class GenericClass<T> {} > > public class Program > { > public static void Main() > { > WrapType(typeof(NonGenericClass)); // This works fine > WrapType(typeof(GenericClass<>)); // This throws the above > exception > } > > public static Type WrapType(Type typeToWrap) > { > // Create the wrapper type > AppDomain appDomain = Thread.GetDomain(); > AssemblyBuilder assemblyBuilder = appDomain.DefineDynamicAssembly(new > AssemblyName("Example"), AssemblyBuilderAccess.Run); > ModuleBuilder module = assemblyBuilder.DefineDynamicModule(" > Example.dll"); > TypeBuilder typeBuilder = module.DefineType("Wrappers." + > typeToWrap.Name, typeToWrap.Attributes, typeToWrap); > > // Setup generic arguments > Type[] genericParameterTypes = typeToWrap.GetGenericArguments(); > > if (genericParameterTypes.Length > 0) > { > string[] genericParameterNames = new string[ > genericParameterTypes.Length]; > for (int idx = 0; idx < genericParameterTypes.Length; idx++) > genericParameterNames[idx] = > genericParameterTypes[idx].Name; > > GenericTypeParameterBuilder[] genericBuilders = > typeBuilder.DefineGenericParameters (genericParameterNames); > > for (int idx = 0; idx < genericBuilders.Length ; idx++) > { > > genericBuilders[idx].SetGenericParameterAttributes(genericParameterTypes[idx].GenericParameterAttributes); > foreach (Type type in > genericParameterTypes[idx].GetGenericParameterConstraints()) > genericBuilders[idx].SetBaseTypeConstraint(type); > } > } > > // Return wrapper type > return typeBuilder.CreateType(); > } > } -- http://www.agileprogrammer.com/dotnetguy/ http://www.flickr.com/photos/dotnetguy/ http://www.last.fm/user/dotnetguy/ (\__/) (='.'=) This is Bunny. Copy and paste bunny into your (")_(") signature to help him gain world domination. =================================== This list is hosted by DevelopMentor 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
