在运行时实现接口:未实现get_Value方法

Question

我试图在运行时定义一个继承自已知类并实现接口的类型.

public class ParentClass
{
}

public interface IImplementMe
{
    double Value{get;set}
}

以下是显示我如何实现目标的代码段.

   public class ClassBuilder
   {
    public Type Build()
    {
        try
        {
            AssemblyName assemblyName = new AssemblyName("DataBuilderAssembly");
            AssemblyBuilder assemBuilder = Thread.GetDomain().DefineDynamicAssembly(assemblyName, AssemblyBuilderAccess.Run);
            ModuleBuilder moduleBuilder = assemBuilder.DefineDynamicModule("DataBuilderModule");
            TypeBuilder typeBuilder = moduleBuilder.DefineType("NewClass", TypeAttributes.Class, typeof(ParentClass));
            typeBuilder.AddInterfaceImplementation(typeof(IImplementMe));
            BuildProperty(typeBuilder, "Value", typeof(double));
            Type type = typeBuilder.CreateType();

            return type;
        }
        catch (Exception e)
        {
            return null;
        }

    }

    private void BuildProperty(TypeBuilder typeBuilder, string name, Type type)
    {
        FieldBuilder field = typeBuilder.DefineField("m" + name, type, FieldAttributes.Private);
        PropertyBuilder propertyBuilder = typeBuilder.DefineProperty(name, PropertyAttributes.None, type, null);

        MethodAttributes getSetAttr = MethodAttributes.Public | MethodAttributes.HideBySig;

        MethodBuilder getter = typeBuilder.DefineMethod("get_" + name, getSetAttr, type, Type.EmptyTypes);

        ILGenerator getIL = getter.GetILGenerator();
        getIL.Emit(OpCodes.Ldarg_0);
        getIL.Emit(OpCodes.Ldfld, field);
        getIL.Emit(OpCodes.Ret);

        MethodBuilder setter = typeBuilder.DefineMethod("set_" + name, getSetAttr, null, new Type[] { type });

        ILGenerator setIL = setter.GetILGenerator();
        setIL.Emit(OpCodes.Ldarg_0);
        setIL.Emit(OpCodes.Ldarg_1);
        setIL.Emit(OpCodes.Stfld, field);
        setIL.Emit(OpCodes.Ret);


        propertyBuilder.SetGetMethod(getter);
        propertyBuilder.SetSetMethod(setter);
    }
}

出于某种原因,我在调用时遇到"get_Value方法未实现"异常typeBuilder.CreateType().到目前为止无法看到背后的原因.

Answer 1

c#隐式接口实现(通过名称匹配)仅是方便的; 手动执行时,需要使用typeBuilder.DefineMethodOverride将虚拟方法表中的每个关联起来,传入新的(生成的)方法和接口方法来满足.必须为要实现的每个接口的每个方法执行此操作.

Answer 2

将您的行更改为:

MethodAttributes getSetAttr = MethodAttributes.Public | 
    MethodAttributes.HideBySig | MethodAttributes.SpecialName | MethodAttributes.Virtual;

你的代码然后为我工作.(虚拟是必需的.)