如何获取C#中方法的执行时间以及其代码注入详解

DateTime dateTime = DateTime.Now;

MyFunc();

Console.WriteLine((DateTime.Now - dateTime).TotalMilliseconds);

Stopwatch stopwatch = new Stopwatch();
stopwatch.Start();
MyFunc();

stopwatch.Stop();

Console.WriteLine(stopwatch.ElapsedMilliseconds); //本次MyFunc()方法的运行毫秒数

//重置计时器
stopwatch.Restart(); //此处可以使用stopwatch.Reset(); stopwatch.Start();组合代替

MyFunc();

stopwatch.Stop();
Console.WriteLine(stopwatch.ElapsedMilliseconds); //本次MyFunc()方法的运行毫秒数

using System;
using System.IO;
using System.Linq;
using System.Diagnostics;
using Mono.Cecil;
using Mono.Cecil.Cil;
using Mono.Collections.Generic;

static void Main(string[] args)
 {
 for (int i = 0; i < args.Length; i++)
 {
 FileStream fileStream = new FileStream(args[i], FileMode.Open);
 if (fileStream != null)
 {
 AssemblyDefinition aD = AssemblyDefinition.ReadAssembly(fileStream);
 ModuleDefinition mD = aD.MainModule;
 Collection<TypeDefinition> typeDefinition = mD.Types;
 foreach (TypeDefinition type in typeDefinition)
 {
  if (type.IsClass)
  {
  foreach (MethodDefinition method in type.Methods)
  {
  if (method.IsPublic && !method.IsConstructor)
  {
  ILProcessor il = method.Body.GetILProcessor();
  TypeReference stT = mD.ImportReference(typeof(Stopwatch));
  VariableDefinition stV = new VariableDefinition(stT);
  method.Body.Variables.Add(stV);
  Instruction first = method.Body.Instructions.First();
  il.InsertBefore(first, il.Create(OpCodes.Newobj, 　　　　　　　　　　　　　　　　　　　　　　mD.ImportReference(typeof(Stopwatch).GetConstructor(new Type[] { }))));
  il.InsertBefore(first, il.Create(OpCodes.Stloc_S, stV));
  il.InsertBefore(first, il.Create(OpCodes.Ldloc_S, stV));
  il.InsertBefore(first, il.Create(OpCodes.Callvirt,　　　　　　　　　　　　　　　　　　　　　　mD.ImportReference(typeof(Stopwatch).GetMethod("Start"))));

  Instruction @return = method.Body.Instructions.Last();
  il.InsertBefore(@return, il.Create(OpCodes.Ldloc_S, stV));
  il.InsertBefore(@return, il.Create(OpCodes.Callvirt, 　　　　　　　　　　　　　　　　　　　　　　mD.ImportReference(typeof(Stopwatch).GetMethod("Stop"))));

  il.InsertBefore(@return, il.Create(OpCodes.Ldstr, $"{method.FullName} run time: "));
  il.InsertBefore(@return, il.Create(OpCodes.Ldloc_S, stV));
  il.InsertBefore(@return, il.Create(OpCodes.Callvirt, 　　　　　　　　　　　　　　　　　　　　　　mD.ImportReference(typeof(Stopwatch).GetMethod("get_ElapsedMilliseconds"))));
  il.InsertBefore(@return, il.Create(OpCodes.Box, mD.ImportReference(typeof(long))));
  il.InsertBefore(@return, il.Create(OpCodes.Call, 　　　　　　　　　　　　　　　　　　　　　　mD.ImportReference(typeof(string).GetMethod("Concat", new Type[] { typeof(object), typeof(object) }))));
  il.InsertBefore(@return, il.Create(OpCodes.Call, 　　　　　　　　　　　　　　　　　　　　　　mD.ImportReference(typeof(Console).GetMethod("WriteLine", new Type[] { typeof(string) }))));
  }
  }
  }
 }
 FileInfo fileInfo = new FileInfo(args[i]);
 string fileName = fileInfo.Name;
 int pointIndex = fileName.LastIndexOf('.');
 string frontName = fileName.Substring(0, pointIndex);
 string backName = fileName.Substring(pointIndex, fileName.Length - pointIndex);
 string writeFilePath = Path.Combine(fileInfo.Directory.FullName, frontName + "_inject" + backName);
 aD.Write(writeFilePath);
 Console.WriteLine($"Success! Output path: {writeFilePath}");
 fileStream.Dispose();
 }
 }
 Console.Read();
 }

using System;

public class MyClass
{
 public void MyFunc()
 {
 int num = 1;
 for (int i = 0; i < int.MaxValue; i++)
 {
 num++;
 }
 }
}
public class Program
{
 public static void Main(string[] args)
 {
 MyClass myObj = new MyClass();
 myObj.MyFunc();
 Console.Read();
 }
}