c# 根据当前时间获取,本周,本月,本季度,月初,月末,各个时间段

2017-05-05 16:39
  1. DateTime dt = DateTime.Now;  //当前时间  
  2. DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss") //24小时制 
  3. DateTime.Now.ToString("yyyy-MM-dd hh:mm:ss")  //12小时制    
  4. DateTime startWeek = dt.AddDays(1 - Convert.ToInt32(dt.DayOfWeek.ToString("d")));  //本周周一  
  5. DateTime endWeek = startWeek.AddDays(6);  //本周周日    
  6. DateTime startMonth = dt.AddDays(1 - dt.Day);  //本月月初  
  7. DateTime endMonth = startMonth.AddMonths(1).AddDays(-1);  //本月月末  //DateTime endMonth = startMonth.AddDays((dt.AddMonths(1) - dt).Days - 1);  //本月月末    
  8. DateTime startQuarter = dt.AddMonths(0 - (dt.Month - 1) % 3).AddDays(1 - dt.Day);  //本季度初  
  9. DateTime endQuarter = startQuarter.AddMonths(3).AddDays(-1);  //本季度末    
  10. DateTime startYear = new DateTime(dt.Year, 1, 1);  //本年年初 
  11. DateTime endYear = new DateTime(dt.Year, 12, 31);  //本年年末     至于昨天、明天、上周、上月、上季度、上年度等等,只要AddDays()、AddMonths()、AddYears()这几种方法组合一下就可以了。
  12. //C#中datetime的使用                 
  13. //如本年度销售额、本季度利润、本月新增客户                  
  14. //C#里内置的DateTime基本上都可以实现这些功能,巧用DateTime会使你处理这些事来变轻松多了                                  
  15. //今天                  
  16. DateTime.Now.Date.ToShortDateString();                   
  17. //昨天,就是今天的日期减一                  
  18. DateTime.Now.AddDays(-1).ToShortDateString();                   
  19. //明天,同理,加一                  
  20. DateTime.Now.AddDays(1).ToShortDateString();                    
  21. //本周(要知道本周的第一天就得先知道今天是星期几,从而得知本周的第一天就是几天前的那一天,要注意的是这里的每一周是从周日始至周六止                  
  22. DateTime.Now.AddDays(Convert.ToDouble((0 -  Convert.ToInt16(DateTime.Now.DayOfWeek)))).ToShortDateString();                   
  23. DateTime.Now.AddDays(Convert.ToDouble((6 -  Convert.ToInt16(DateTime.Now.DayOfWeek)))).ToShortDateString();                   
  24. //如果你还不明白,再看一下中文显示星期几的方法就应该懂了                  
  25. //由于DayOfWeek返回的是数字的星期几,我们要把它转换成汉字方 便我们阅读,有些人可能会用switch来一个一个地对照,其实不用那么麻烦的                               
  26. string[] Day = new string[] { "星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六" };                    
  27. Day[Convert.ToInt16(DateTime.Now.DayOfWeek)];                  //上周,同理,一个周是7天,上周就是本周再减去7天,下周也是一样                 
  28. DateTime.Now.AddDays(Convert.ToDouble((0 -  Convert.ToInt16(DateTime.Now.DayOfWeek))) - 7).ToShortDateString();                   
  29. DateTime.Now.AddDays(Convert.ToDouble((6 -  Convert.ToInt16(DateTime.Now.DayOfWeek))) - 7).ToShortDateString(); //下周                  
  30. DateTime.Now.AddDays(Convert.ToDouble((0 -  Convert.ToInt16(DateTime.Now.DayOfWeek))) + 7).ToShortDateString();                   
  31. DateTime.Now.AddDays(Convert.ToDouble((6 -  Convert.ToInt16(DateTime.Now.DayOfWeek))) + 7).ToShortDateString();  //本月,很多人都会说本月的第一天嘛肯定是1号,最后一天就是下个月一号再减一天。当然这是对的                 
  32. //一般的写法                 
  33. DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString() + "1"; //第一天                 
  34. DateTime.Parse(DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString() +  "1").AddMonths(1).AddDays(-1).ToShortDateString();//最后一天                 
  35. //巧用C#里ToString的字符格式化更简便                  
  36. DateTime.Now.ToString("yyyy-MM-01");                    
  37. DateTime.Parse(DateTime.Now.ToString("yyyy-MM-01")).AddMonths(1).AddDays(-1).ToShortDateString();                                   
  38. DateTime.Parse(DateTime.Now.ToString("yyyy-MM-01")).AddMonths(-1).ToShortDateString();                   //上个月,减去一个月份   
  39. DateTime.Parse(DateTime.Now.ToString("yyyy-MM-01")).AddMonths(1).ToShortDateString();                   //下个月,加去一个月份
  40. DateTime.Now.AddDays(7).ToShortDateString();                 //7天前                  
  41. DateTime.Now.AddDays(-7).ToShortDateString();//7天后       
  42. //本年度,用ToString的字符格式化我们也很容易地算出本年度的第一天和最后一天                   
  43. DateTime.Parse(DateTime.Now.ToString("yyyy-01-01")).ToShortDateString();                    
  44. DateTime.Parse(DateTime.Now.ToString("yyyy-01-01")).AddYears(1).AddDays(-1).ToShortDateString();                                   
  45. DateTime.Parse(DateTime.Now.ToString("yyyy-01-01")).AddYears(-1).ToShortDateString();                 //上年度,不用再解释了吧     
  46. DateTime.Parse(DateTime.Now.ToString("yyyy-01-01")).AddDays(-1).ToShortDateString();                                
  47. DateTime.Parse(DateTime.Now.ToString("yyyy-01-01")).AddYears(1).ToShortDateString();                   //下年度     
  48. DateTime.Parse(DateTime.Now.ToString("yyyy-01-01")).AddYears(2).AddDays(-1).ToShortDateString();                  //本季度,很多人都会觉得这里难点,需要写个长长的过程来判断。其实不用的,我们都知道一年四个季度,一个季度三个月                  //首先我们先把日期推到本季度第一个月,然后这个月的第一天就是本季度的第一天了                  
  49. DateTime.Now.AddMonths(0 - ((DateTime.Now.Month - 1) % 3)).ToString("yyyy-MM-01");                  //同理,本季度的最后一天就是下季度的第一天减一                 
  50. DateTime.Parse(DateTime.Now.AddMonths(3 - ((DateTime.Now.Month - 1) %  3)).ToString("yyyy-MM-01")).AddDays(-1).ToShortDateString();    //下季度,相信你们都知道了。。。。收工                  
  51. DateTime.Now.AddMonths(3 - ((DateTime.Now.Month - 1) % 3)).ToString("yyyy-MM-01");                   
  52. DateTime.Parse(DateTime.Now.AddMonths(6 - ((DateTime.Now.Month - 1) %  3)).ToString("yyyy-MM-01")).AddDays(-1).ToShortDateString();                 //上季度                 
  53. DateTime.Now.AddMonths(-3 - ((DateTime.Now.Month - 1) % 3)).ToString("yyyy-MM-01");                    
  54. DateTime.Parse(DateTime.Now.AddMonths(0 - ((DateTime.Now.Month - 1) %  3)).ToString("yyyy-MM-01")).AddDays(-1).ToShortDateString(); 

转自:http://wenku.baidu.com/link?url=Kq2mVGamPH-nC8y8SwACBd9KqXq41FUkTigP6jod0vyptUSw2HiURuwHzalkAwCmUodxj2nK55nRdj2CSqC77DAcyhyybJ8wsMrIT3aUfR3