c# - 使用 Reflection.Emit 调用基类方法

Question

我已经设置了我的代码来定义类型、设置父类型以及实现接口(interface)。我遇到的问题是，当我去创建类型时，它说它找不到接口(interface)的方法实现，即使这些方法是在父类型上实现的。据我所知，您需要为这种情况定义传递方法，这是我的代码:

    public interface IService<TDto, TId>
{
    Task<TId> CreateAsync(TDto entity);
    Task<bool> DeleteAsync(TId id);
    Task<bool> UpdateAsync(TDto entity);
    Task<List<TDto>> GetAllAsync();
    Task<TDto> GetAsync(TId id);
    TDto Get(TId id);
    Task<IEnumerable<TDto>> GetAllPagedAsync(Int32 page, Int32 take);
    Task<Int32> GetCountAsync();
    Task<object> GetForIdsAsync(TId[] ids, Int32? page = null, Int32? pageSize = null);
    object GetForIds(TId[] ids, Int32? page = null, Int32? pageSize = null);
    Task<bool> DeleteForIdsAsync(TId[] ids);
    Task<List<TDto>> CloneEntitiesAsync(List<TDto> dtos);
    Task<IList> GetForTypesAndIdsAsync(List<string> types, List<object[]> typeIds);
    Task<object> GetByConditionsAsync(Query query);
    Task<object> ExceptIdsAsync(TId[] ids, Int32? page = null, Int32? pageSize = null);
    bool Merge(TDto dto);
}

public Type[] CreateServiceType(Type dtoType, Type entityType, ModuleBuilder moduleBuilder)
        {
            string namespaceName = string.Format("Services.{0}", ProfileNamePlural);

            TypeBuilder iserviceTypeBuilder =
                moduleBuilder.DefineType(
                string.Format("{0}.I{1}Service", namespaceName, ClassName), 
                TypeAttributes.Interface | TypeAttributes.Abstract);

            var baseIServiceType = typeof (IService<,>).MakeGenericType(dtoType, entityType);
            iserviceTypeBuilder.AddInterfaceImplementation(baseIServiceType);

            Type iserviceType = iserviceTypeBuilder.CreateType();

            var baseType = typeof(AService<,,>).MakeGenericType(dtoType, entityType, typeof(Guid));

            string serviceClassName = string.Format("{0}.{1}Service", namespaceName, ClassName);

            TypeBuilder serviceTypeBuilder =
                moduleBuilder.DefineType(serviceClassName, TypeAttributes.Public);

            serviceTypeBuilder.SetParent(baseType);

            serviceTypeBuilder
                .AddInterfaceImplementation(iserviceType);

            var repositoryType = typeof(IRepository<>).MakeGenericType(entityType);

            ConstructorBuilder ctorBuilder =
                serviceTypeBuilder.DefineConstructor(
                    MethodAttributes.Public,
                    CallingConventions.Standard,
                    new[] { repositoryType });

            var baseConstructor =
                baseType.GetConstructor(
                BindingFlags.NonPublic | BindingFlags.FlattenHierarchy | BindingFlags.Instance,
                    null, 
                    new[] { repositoryType }, 
                    null);

            var ilGenerator = ctorBuilder.GetILGenerator();

            // Generate constructor code
            ilGenerator.Emit(OpCodes.Ldarg_0);                // push "this" onto stack. 
            ilGenerator.Emit(OpCodes.Ldarg_1);
            ilGenerator.Emit(OpCodes.Call, baseConstructor);
            ilGenerator.Emit(OpCodes.Ret);

            DefinePassThroughs(ref serviceTypeBuilder, baseType, baseIServiceType);

            return new[] { serviceTypeBuilder.CreateType(), iserviceType };
        }

private void DefinePassThroughs(ref TypeBuilder typeBuilder, Type baseType, Type iServiceType)
        {
            var virtualMethods = iServiceType.GetMethods();
            foreach (var imethod in virtualMethods)
            {
                var method = baseType.GetMethod(imethod.Name);
                var paramTypes = method.GetParameters().Select(x => x.ParameterType).ToArray();

                var passThroughMethod =
                    typeBuilder.DefineMethod(
                    method.Name, 
                    MethodAttributes.Public, 
                    CallingConventions.Standard,
                    method.ReturnType,
                    paramTypes);

                var il = passThroughMethod.GetILGenerator();
                il.Emit(OpCodes.Ldarg_0);
                for (var i = 0; i < paramTypes.Length; i++)
                {
                   il.Emit(OpCodes.Ldarg, i + 1); 
                }

                il.EmitCall(OpCodes.Callvirt, method, null);
                il.Emit(OpCodes.Ret);
                typeBuilder.DefineMethodOverride(passThroughMethod, imethod);
            }
        }

当我尝试创建类型实例时出现此错误:“方法实现中的正文签名和声明不匹配。”我在这里缺少什么？

Answer 1

even though those methods are implemented on the parent type.

由于父类型已经实现了接口(interface)，派生类型不需要显式传递(尽管您可能需要将接口(interface)的父类实现声明为虚拟)。

看看这个答案:https://stackoverflow.com/a/3621600/1698246