DateTime.Now的Millisecond

Question

 static void Main(string[] args)
        {            for(int i =0;i<100;i++)
            {
               
                Console.WriteLine( i.ToString()+"__"+ DateTime.Now.ToString()+":"+DateTime.Now.Millisecond.ToString());
                
            }
}
怎么才能保证for循环执行时，打印的DateTime.Now不一样，，主要是指Millisecond，，毫秒我试过在for里面加上Thead.Sleep(1);但是打印出来的东西还是有些毫秒是一样的

Answer 1

我记得Thread.Sleep最小间隔是10毫秒。

Answer 2

如果你想要按1递增的话，实现起来比较麻烦，你不如让Sleep的时间长一些。
Sleep在毫秒等级上，不是你写多少就能停止多长时间的，有些误差

Answer 3

 for (int i = 0; i < 100; i++)
            {
                Console.WriteLine(i.ToString() + "__" + DateTime.Now.ToString() + ":" + DateTime.Now.Millisecond.ToString());
                Thread.Sleep(1);
            }没啥问题啊

Answer 4

一个歪招
DateTime dt = DateTime.Now;
for (int i = 0; i < 100; i++)
{
    for (int j = 0; j < 10000000; j++)
    {
    }
    dt = DateTime.Now;
    this.listBox1.Items.Add(i.ToString() + "__" + dt.ToString() + ":" + dt.Millisecond.ToString());
}

Answer 5

数据表明加上Sleep(1)不会重复
0__9/27/2011 16:57:36 PM:790
1__9/27/2011 16:57:36 PM:794
2__9/27/2011 16:57:36 PM:796
3__9/27/2011 16:57:36 PM:799
4__9/27/2011 16:57:36 PM:801
5__9/27/2011 16:57:36 PM:803
6__9/27/2011 16:57:36 PM:805
7__9/27/2011 16:57:36 PM:807
8__9/27/2011 16:57:36 PM:824
9__9/27/2011 16:57:36 PM:832
10__9/27/2011 16:57:36 PM:834
11__9/27/2011 16:57:36 PM:836
12__9/27/2011 16:57:36 PM:838
13__9/27/2011 16:57:36 PM:841
14__9/27/2011 16:57:36 PM:843
15__9/27/2011 16:57:36 PM:845
16__9/27/2011 16:57:36 PM:847
17__9/27/2011 16:57:36 PM:849
18__9/27/2011 16:57:36 PM:851
19__9/27/2011 16:57:36 PM:853
20__9/27/2011 16:57:36 PM:855
21__9/27/2011 16:57:36 PM:857
22__9/27/2011 16:57:36 PM:859
23__9/27/2011 16:57:36 PM:861
24__9/27/2011 16:57:36 PM:863
25__9/27/2011 16:57:36 PM:865
26__9/27/2011 16:57:36 PM:867
27__9/27/2011 16:57:36 PM:869
28__9/27/2011 16:57:36 PM:873
29__9/27/2011 16:57:36 PM:877
30__9/27/2011 16:57:36 PM:881
31__9/27/2011 16:57:36 PM:884
32__9/27/2011 16:57:36 PM:890
33__9/27/2011 16:57:36 PM:894
34__9/27/2011 16:57:36 PM:897
35__9/27/2011 16:57:36 PM:902
36__9/27/2011 16:57:36 PM:905
37__9/27/2011 16:57:36 PM:908
38__9/27/2011 16:57:36 PM:911
39__9/27/2011 16:57:36 PM:917
40__9/27/2011 16:57:36 PM:921
41__9/27/2011 16:57:36 PM:924
42__9/27/2011 16:57:36 PM:927
43__9/27/2011 16:57:36 PM:930
44__9/27/2011 16:57:36 PM:933
45__9/27/2011 16:57:36 PM:936
46__9/27/2011 16:57:36 PM:939
47__9/27/2011 16:57:36 PM:942
48__9/27/2011 16:57:36 PM:946
49__9/27/2011 16:57:36 PM:948
50__9/27/2011 16:57:36 PM:951
51__9/27/2011 16:57:36 PM:954
52__9/27/2011 16:57:36 PM:957
53__9/27/2011 16:57:36 PM:960
54__9/27/2011 16:57:36 PM:964
55__9/27/2011 16:57:36 PM:967
56__9/27/2011 16:57:36 PM:970
57__9/27/2011 16:57:36 PM:973
58__9/27/2011 16:57:36 PM:976
59__9/27/2011 16:57:36 PM:979
60__9/27/2011 16:57:36 PM:986
61__9/27/2011 16:57:36 PM:989
62__9/27/2011 16:57:36 PM:991
63__9/27/2011 16:57:36 PM:994
64__9/27/2011 16:57:36 PM:997
65__9/27/2011 16:57:37 PM:0
66__9/27/2011 16:57:37 PM:3
67__9/27/2011 16:57:37 PM:5
68__9/27/2011 16:57:37 PM:8
69__9/27/2011 16:57:37 PM:11
70__9/27/2011 16:57:37 PM:14
71__9/27/2011 16:57:37 PM:17
72__9/27/2011 16:57:37 PM:21
73__9/27/2011 16:57:37 PM:24
74__9/27/2011 16:57:37 PM:27
75__9/27/2011 16:57:37 PM:30
76__9/27/2011 16:57:37 PM:32
77__9/27/2011 16:57:37 PM:35
78__9/27/2011 16:57:37 PM:38
79__9/27/2011 16:57:37 PM:41
80__9/27/2011 16:57:37 PM:44
81__9/27/2011 16:57:37 PM:47
82__9/27/2011 16:57:37 PM:52
83__9/27/2011 16:57:37 PM:55
84__9/27/2011 16:57:37 PM:58
85__9/27/2011 16:57:37 PM:61
86__9/27/2011 16:57:37 PM:64
87__9/27/2011 16:57:37 PM:67
88__9/27/2011 16:57:37 PM:70
89__9/27/2011 16:57:37 PM:73
90__9/27/2011 16:57:37 PM:75
91__9/27/2011 16:57:37 PM:78
92__9/27/2011 16:57:37 PM:81
93__9/27/2011 16:57:37 PM:84
94__9/27/2011 16:57:37 PM:87
95__9/27/2011 16:57:37 PM:91
96__9/27/2011 16:57:37 PM:94
97__9/27/2011 16:57:37 PM:97
98__9/27/2011 16:57:37 PM:100
99__9/27/2011 16:57:37 PM:103
Press any key to continue . . .

Answer 6

不可能保证...因为非实时系统系统时钟是有精度限制的，PC Windows系统大约是15毫秒，也就是说在系统时钟的一个Tick内这个值是不变的...你这问题跟月经的Random重复值问题本质是一样的...

Answer 7

虽然无法保证精确的时间但是Sleep(1)能够确保等待的时间大于1毫秒
也就是说他的MilliSecond是不会重复才对

Answer 8

你在想当然，精度只有15毫秒，你sleep1毫秒怎么可能...除非你的计算机被各种任务阻塞慢的不像话，稍微正常一点的计算机都不可能...

Answer 9

问题时Sleep的时候线程被挂起了照你这么说那线程至少15毫秒以后才能再得到执行机会事实显然不是这样

Answer 10

事实是sleep 1毫秒很可能系统时钟还没有走完一个Tick...你为什么不多测试几次呢...而且人家楼主一开始就说了...

Answer 11

你也是想当然，都是系统时钟怎么可能有差别...只有sleep超过系统时钟精度才行，否则就不能用系统时钟，只有CPU晶振才足够快...

Answer 12

事实上我的Thread.Sleep(1)是加在打印之前，，加在打印之后，就没有重复的了。。如Icedmilk打印的效果了。。
请vrhero和Icedmilk告诉我哈呢

Answer 13

搞开发的经常会开发一种玩笑，对于一些自认为很牛的人，如果遇到了bug，会自嘲地说：“我是不人品不行，所以才出这种bug？”。肯到你的这个“设计”我也只好苦笑。你知道电脑运行有多快？你硬要连续运行两次 DateTime.Now 返回的毫秒数必须不一样，这是什么“研究”呢？想转而研究如何编写出100%保证低效率的程序的方法么？

Answer 14

既然一个tick都没走完，那就是系统认为时间没变，那线程怎么会继续计时不精确只会导致Sleep(1)消耗掉的时间大于1ms我在家里的机器又试了下，确实要比公司里的机器间隔小多了，不过依然没有重复

Answer 15

我的测试数据表明Sleep(1)会出现2-5不等的重复数据

Answer 16

static void Main(string[] args)
        {            for(int i =0;i<100;i++)
            {
               
                Console.WriteLine(System.Environment.TickCount.ToString());
                
            }
}