编写高质量代码改善C#程序的157个建议——建议88：并行并不总是速度更快

static void Main(string[] args)  
{  
    Stopwatch watch = new Stopwatch();  
    watch.Start();  
    DoInFor();  
    watch.Stop();  
 
    Console.WriteLine("同步耗时：{0}", watch.Elapsed);  
 
    watch.Restart();  
    DoInParalleFor();  
    watch.Stop();  
    Console.WriteLine("并行耗时：{0}", watch.Elapsed);  
 
    Console.ReadKey();  
}  
 
static void DoSomething()  
{  
    for (int i = 0; i < 10; i++)  
    {  
        i++;  
    }  
}  
 
static void DoInFor()  
{  
    for (int i = 0; i < 200; i++)  
    {  
        DoSomething();  
    }  
}  
 
static void DoInParalleFor()  
{  
    Parallel.For(0, 200, (i) =>
    {  
        DoSomething();  
    });  
}