using System;

using System.Net;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Documents;

using System.Windows.Ink;

using System.Windows.Input;

using System.Windows.Media;

using System.Windows.Media.Animation;

using System.Windows.Shapes;

using System.Reflection;

using System.Reflection.Emit;

namespace Emit

{

    public class CModuleBuilder

    {

        public static void Demo(System.Windows.Controls.TextBlock outputBlock)

        {

            // 创建应用程序域.

            AppDomain myCurrentDomain = AppDomain.CurrentDomain;

            AssemblyName myAssemblyName = new AssemblyName("TempAssembly");

            // 创建动态程序集

            AssemblyBuilder myAssemblyBuilder = myCurrentDomain.DefineDynamicAssembly

                           (myAssemblyName, AssemblyBuilderAccess.Run);

            // 动态模块.

            ModuleBuilder myModuleBuilder = myAssemblyBuilder.

                                            DefineDynamicModule("TempModule");

            // 定义类.

            TypeBuilder myTypeBuilder = myModuleBuilder.DefineType

                                             ("TempClass", TypeAttributes.Public);

            // 添加字段.

            FieldBuilder greetingField = myTypeBuilder.DefineField("Greeting",

                                                   typeof(String), FieldAttributes.Public);

            Type[] myMethodArgs = { typeof(String) };

            // 动态类的方法.

            MethodBuilder myMethod = myTypeBuilder.DefineMethod("MyMethod",

               MethodAttributes.Public, CallingConventions.Standard, typeof(String), myMethodArgs);

            // 方法的属性.

            MethodInfo stringConcat = typeof(String).GetMethod("Concat",

               BindingFlags.Static | BindingFlags.Public, Type.DefaultBinder,

               new Type[] { typeof(String), typeof(String) },

               null);

            ILGenerator methodIL = myMethod.GetILGenerator();

            methodIL.EmitWriteLine("In the method...");

            methodIL.Emit(OpCodes.Ldarg_0);

            methodIL.Emit(OpCodes.Ldarg_1);

            methodIL.Emit(OpCodes.Stfld, greetingField);

            methodIL.Emit(OpCodes.Ldstr, "Hello, ");

            methodIL.Emit(OpCodes.Ldarg_1);

            methodIL.Emit(OpCodes.Call, stringConcat);

            methodIL.Emit(OpCodes.Ret);

            Type myType = myTypeBuilder.CreateType();

            MethodInfo myMethodInfo =

                                    myType.GetMethod("MyMethod");

            // Get the token used to identify the method within this module.

            MethodToken myMethodToken =

                              myModuleBuilder.GetMethodToken(myMethodInfo);

            outputBlock.Text += String.Format(

               "Token used to identify the method of 'myType' within the module is {0:x}\n",

               myMethodToken.Token);

            object[] args = { "World!" };

            object myObject = Activator.CreateInstance(myType);

            outputBlock.Text += "Return value from MyMethod(\"World!\"): " +

               myMethodInfo.Invoke(myObject, args);

        }

    }

}