MSIL实用指南-数学运算

C#支持的数学运算是加、减、乘、除、取模，它们对应的指令是
Add、Sub、Mul、Div、Rem。

这五个运算都需要两个参数，它们的通用步骤
1.生成加载左边变量
2.生成加载右边变量
3.生成运算指令

实例：

ilGenerator.Emit(OpCodes.Ldarg_0);

ilGenerator.Emit(OpCodes.Ldarg_1);

ilGenerator.Emit(OpCodes.Sub);

完整的程序如下：

using System;

using System.Reflection;

using System.Reflection.Emit;

namespace LX1_ILDemo

{

    class Demo16_NumberOP

    {

        static string binaryName = "Demo16_NumberOP.exe";

        static string namespaceName = "LX1_ILDemo";

        static string typeName = "NumberOPDemo";

        static AssemblyBuilder assemblyBuilder;

        static ModuleBuilder moduleBuilder;

        static TypeBuilder typeBuilder;

        static MethodBuilder mainMethod;

        static MethodBuilder testMethod;

        static void Emit_Test()

        {

            testMethod = typeBuilder.DefineMethod("TestOP", MethodAttributes.Public

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

            var println= typeof(Console).GetMethod("WriteLine", new Type[] { typeof(double) });

            var ilGenerator = testMethod.GetILGenerator();

            ilGenerator.Emit(OpCodes.Ldarg_0);

            ilGenerator.Emit(OpCodes.Ldarg_1);

            ilGenerator.Emit(OpCodes.Add);

            ilGenerator.Emit(OpCodes.Call, println);

            ilGenerator.Emit(OpCodes.Ldarg_0);

            ilGenerator.Emit(OpCodes.Ldarg_1);

            ilGenerator.Emit(OpCodes.Sub);

            ilGenerator.Emit(OpCodes.Call, println);

            ilGenerator.Emit(OpCodes.Ldarg_0);

            ilGenerator.Emit(OpCodes.Ldarg_1);

            ilGenerator.Emit(OpCodes.Mul);

            ilGenerator.Emit(OpCodes.Call, println);

            ilGenerator.Emit(OpCodes.Ldarg_0);

            ilGenerator.Emit(OpCodes.Ldarg_1);

            ilGenerator.Emit(OpCodes.Div);

            ilGenerator.Emit(OpCodes.Call, println);

            ilGenerator.Emit(OpCodes.Ldarg_0);

            ilGenerator.Emit(OpCodes.Ldarg_1);

            ilGenerator.Emit(OpCodes.Rem);

            ilGenerator.Emit(OpCodes.Call, println);

            ilGenerator.Emit(OpCodes.Ret);

        }

        public static void Generate()

        {

            InitAssembly();

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

            Emit_Test();

            GenerateMain();

            assemblyBuilder.SetEntryPoint(mainMethod, PEFileKinds.ConsoleApplication);

            SaveAssembly();

            Console.WriteLine("生成成功");

        }

        static void GenerateMain()

        {

            mainMethod = typeBuilder.DefineMethod("Main", MethodAttributes.Public

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

            var ilGenerator = mainMethod.GetILGenerator();

            ilGenerator.Emit(OpCodes.Ldc_R8,(double));

            ilGenerator.Emit(OpCodes.Ldc_R8, (double));

            ilGenerator.Emit(OpCodes.Call, testMethod);

            ilGenerator.Emit(OpCodes.Call, typeof(Console).GetMethod("ReadKey", new Type[] { }));

            ilGenerator.Emit(OpCodes.Pop);

            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);

        }

    }

}

巴特西

MSIL实用指南-数学运算

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