"Joe McMenimen" wrote:

> I am trying to use the Reflection Emit capability of the framework to
> dynamically inherit a base class. I want to call the base classes constructor
> with arguments passed into the new classes constructor. I think I am close,
> but get the following error trying to activate the new class.
>
>
> System.Reflection.TargetInvocationException was unhandled
> Message="Exception has been thrown by the target of an invocation."
> Source="mscorlib"
> StackTrace:
> at System.RuntimeMethodHandle._InvokeConstructor(Object[] args,
> SignatureStruct& signature, IntPtr declaringType)
> at System.RuntimeMethodHandle.InvokeConstructor(Object[] args,
> SignatureStruct signature, RuntimeTypeHandle declaringType)
> at System.Reflection.RuntimeConstructorInfo.Invoke(BindingFlags
> invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
> at System.RuntimeType.CreateInstanceImpl(BindingFlags bindingAttr,
> Binder binder, Object[] args, CultureInfo culture, Object[]
> activationAttributes)
> at System.Activator.CreateInstance(Type type, BindingFlags
> bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[]
> activationAttributes)
> at System.Activator.CreateInstance(Type type, BindingFlags
> bindingAttr, Binder binder, Object[] args, CultureInfo culture)
> at ReflectionEmit.Program.Main(String[] args) in C:\Documents and
> Settings\jmcmeni\Desktop\ReflectionEmit\ReflectionEmit\Program.cs:line 47
> at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)
> at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence
> assemblySecurity, String[] args)
> at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
> at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
> at System.Threading.ExecutionContext.Run(ExecutionContext
> executionContext, ContextCallback callback, Object state)
> at System.Threading.ThreadHelper.ThreadStart()
> InnerException: System.InvalidProgramException
> Message="Common Language Runtime detected an invalid program."
> Source="Test"
> StackTrace:
> at AmericanCar..ctor(String , String )
> InnerException:
>
>
> Here is the small sample that I'm trying to get to work.
>
> Any help would be great.
>
> thanks
>
> Joe
>
> Program
>
>
>
> using System;
> using System.Reflection;
> using System.Reflection.Emit;
> using System.Threading;
>
> namespace ReflectionEmit
> {
> class Program
> {
> static void Main(string[] args)
> {
> AssemblyName assemblyName = new AssemblyName();
> assemblyName.Name = "Test";
> AssemblyBuilder assemblyBuilder =
> Thread.GetDomain().DefineDynamicAssembly(assemblyName,
> AssemblyBuilderAccess.RunAndSave);
> ModuleBuilder module;
> module = assemblyBuilder.DefineDynamicModule("Test.dll");
>
> // create a new type to hold our Main method
> TypeBuilder typeBuilder = module.DefineType("AmericanCar",
> TypeAttributes.Public | TypeAttributes.Class, typeof(Car));
>
>
> typeBuilder.DefineDefaultConstructor(MethodAttributes.Public);
> FieldBuilder fb = typeBuilder.DefineField("brand",
> typeof(string), FieldAttributes.Private);
>
> ConstructorInfo ci = typeof(Car).GetConstructor(new Type[] {
> typeof(string) });
>
> ConstructorBuilder cb = typeBuilder.DefineConstructor(
> ci.Attributes,
> ci.CallingConvention, new Type[] { typeof(string),
> typeof(string) });
>
> ILGenerator il = cb.GetILGenerator();
>
> int paramCount = ci.GetParameters().Length;
> il.Emit(OpCodes.Ldarg_0);
> for (int i = 1; i <= paramCount; i++)
> {
> il.Emit(OpCodes.Ldarg_S, i);
> }
> il.Emit(OpCodes.Call, ci);
>
> il.Emit(OpCodes.Ldarg_0);
> il.Emit(OpCodes.Ldarg_2);
> il.Emit(OpCodes.Stfld, fb);
>
> Type type = typeBuilder.CreateType();
> assemblyBuilder.Save("Test.dll");
>
> object o = Activator.CreateInstance(type,
> BindingFlags.CreateInstance, null, new object[]{"Red","Corvette"},
> System.Globalization.CultureInfo.CurrentCulture);
>
> }
>
> }
>
> public class Car
> {
> private string color;
>
> public string Color
> {
> get { return color; }
> set { color = value; }
> }
>
> public Car() { }
>
> public Car(string color)
> {
> this.color = color;
> }
> }
> }
>