在本节我们需要看看这个Mono.Cecil,先来一个简单的认识。
我来在我们的方法执行前后加入我们的输出信息:
原来代码:
class Program
{
static void Main(string[] args)
{
Console.WriteLine("破浪Blog:http://www.cnblogs.com/whitewolf/");
}
}
任务:
1我将在方法执行前后添加一个Console.WriteLine("Method start…");
2方法最后添加Console.WriteLine("Method finish…“);
具体Mono.Cecil Code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Mono.Cecil;
using Mono.Cecil.Cil;
namespace BlogSample
{
class Program
{
static void Main(string[] args)
{
AssemblyDefinition assembiy = AssemblyFactory.GetAssembly(args[0]); //后期版本AssemblyFactory已被去掉,改用AssemblyDefinition.ReadAssembly(fileName);
foreach (Mono.Cecil.TypeDefinition item in assembiy.MainModule.Types)
{
foreach (MethodDefinition method in item.Methods)
{
if (method.Name.Equals("Main"))
{
var ins = method.Body.Instructions[0];
var worker = method.Body.CilWorker;
worker.InsertBefore(ins, worker.Create(OpCodes.Ldstr, "Method start…"));
worker.InsertBefore(ins, worker.Create(OpCodes.Call,
assembiy.MainModule.Import(typeof(Console).GetMethod("WriteLine", new Type[] { typeof(string) }))));
ins = method.Body.Instructions[method.Body.Instructions.Count - 1];
worker.InsertBefore(ins, worker.Create(OpCodes.Ldstr, "Method finish…"));
break;
}
}
}
AssemblyFactory.SaveAssembly(assembiy, "IL_" + args[0]); //后期版本:assembiy.Write(fileName);
Console.Read();
}
}
}
DOS运行结果:
![](https://img.laitimes.com/img/_0nNw4CM6IyYiwiM6ICdiwiInBnauQGZkVDZ4ImN3IGN5YjMmdDMmhDOhNzNyIDNiJmZiRGOfdWbp9CXt92Yu4GZjlGbh5SZslmZxl3Lc9CX6MHc0RHaiojIsJye.jpg)
我们在来看看反编译后的MSIL
C#: