using System;

using System.Reflection;

using System.Reflection.Emit;

namespace LX1_ILDemo

{

    class Demo27_NestedType

    {

        static string binaryName = "Demo27_NestedType.dll";

        static string namespaceName = "LX1_ILDemo";

        static string typeName = "DemoNestedType";

        static AssemblyBuilder assemblyBuilder;

        static ModuleBuilder moduleBuilder;

        static TypeBuilder typeBuilder;

        static void Emit_NestedMethod()

        {

            TypeBuilder nestedBuilder = typeBuilder.DefineNestedType("NestedClass", TypeAttributes.NestedPublic | TypeAttributes.Sealed);

            var testMethod = nestedBuilder.DefineMethod("Hello", MethodAttributes.Public

               | MethodAttributes.Static, typeof(void), new Type[] { });

            ILGenerator ilGenerator = testMethod.GetILGenerator();

            ilGenerator.EmitWriteLine("hello");

            ilGenerator.Emit(OpCodes.Ret);

            Type nestedType = nestedBuilder.CreateType();

        }

        public static void Generate()

        {

            InitAssembly();

            typeBuilder = moduleBuilder.DefineType(namespaceName + "." + typeName, TypeAttributes.Public);

            Emit_NestedMethod();

            GenerateMain();

            SaveAssembly();

            Console.WriteLine("生成成功");

        }

        static void GenerateMain()

        {

           var  mainMethod = typeBuilder.DefineMethod("Test", MethodAttributes.Public

                | MethodAttributes.Static, typeof(void), new Type[] { });

            var ilGenerator = mainMethod.GetILGenerator();

            ilGenerator.EmitWriteLine("Test");

            ilGenerator.Emit(OpCodes.Ret);

        }

        static void InitAssembly()

        {

            AssemblyName assemblyName = new AssemblyName(namespaceName);

            assemblyBuilder = AppDomain.CurrentDomain.DefineDynamicAssembly(assemblyName, AssemblyBuilderAccess.RunAndSave);

            moduleBuilder = assemblyBuilder.DefineDynamicModule(assemblyName.Name, binaryName);

        }

        static void SaveAssembly()

        {

            Type t = typeBuilder.CreateType(); //完成Type，这是必须的

            assemblyBuilder.Save(binaryName);

        }

    }

}