zoukankan      html  css  js  c++  java
  • MSIL实用指南-IL版hello world

    我们学习编程开始时,一般用输出"hello world"的一段程序。

    C#版的"hello world"是

    using System;
    
    namespace L01_HelloDemo
    {
        class HelloWorld
        {
            class Hello
            {
                public static void Main2()
                {
                    Console.WriteLine("Hello World!");
                    Console.ReadKey();
                }
            }
        }
    }
    

    用生成IL方式也可以输出"hello world",它的实现源码是

    using System;
    using System.Reflection;
    using System.Reflection.Emit;
    
    namespace L01_HelloDemo
    {
        class HelloWorldILGenerator
        {
            static string binaryName = "ILHelloWorldDemo.exe";
            static string namespaceName = "ILHelloWorldDemo";
            static string typeName = "HelloWorld";
            
            static AssemblyBuilder assemblyBuilder;
            static ModuleBuilder moduleBuilder;
            static TypeBuilder typeBuilder;
    
            public static void Generate()
            {
                InitAssembly();
    
                /* 生成 public class HelloWorld */
                typeBuilder = moduleBuilder.DefineType(typeName, TypeAttributes.Public);
    
                /* 生成 public static void Main() */
                MethodBuilder mainMethod = typeBuilder.DefineMethod("Main",MethodAttributes.Public | MethodAttributes.Static, typeof(void), new Type[] { });
                ILGenerator methIL = mainMethod.GetILGenerator();
    
                /* 生成 Console.WriteLine("Hello World!"); */
                MethodInfo writeLineMethod = typeof(Console).GetMethod("WriteLine",new Type[]{ typeof(string) });
                methIL.Emit(OpCodes.Ldstr, "Hello World!");
                methIL.Emit(OpCodes.Call, writeLineMethod);
    
                /* 生成 Console.ReadKey(); */
                MethodInfo readKeyMethod = typeof(Console).GetMethod("ReadKey", new Type[] { });
                methIL.Emit(OpCodes.Call, readKeyMethod);
                methIL.Emit(OpCodes.Pop);
    
                methIL.Emit(OpCodes.Ret);
    
                /*  设置assembly入口方法 */
                assemblyBuilder.SetEntryPoint(mainMethod, PEFileKinds.ConsoleApplication);
    
                SaveAssembly();
                Console.WriteLine("生成成功");
                Console.ReadKey();
            }
    
            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);
            }
        }
    }

    调用 HelloWorldILGenerator.Generate()后生成ILHelloWorldDemo.exe文件,打开它运行的效果和C#版的"hello world"的是一样的,

    用ILSpy对ILHelloWorldDemo.exe进行反编译,反编译的源码也和和C#版的"hello world"的是一样的。

  • 相关阅读:
    C#操作REDIS例子
    A C# Framework for Interprocess Synchronization and Communication
    UTF8 GBK UTF8 GB2312 之间的区别和关系
    开源项目选型问题
    Mysql命令大全——入门经典
    RAM, SDRAM ,ROM, NAND FLASH, NOR FLASH 详解(引用)
    zabbix邮件报警通过脚本来发送邮件
    centos启动提示unexpected inconsistency RUN fsck MANUALLY
    rm 或者ls 报Argument list too long
    初遇Citymaker (六)
  • 原文地址:https://www.cnblogs.com/tkt2016/p/8565877.html
Copyright © 2011-2022 走看看