c\#에서 DateTime.Now 함수 의 사용 에 대한 상세 한 설명

//2008 4 24 
     System.DateTime.Now.ToString("D");
     //2008-4-24
     System.DateTime.Now.ToString("d");
     //2008 4 24  16:30:15
     System.DateTime.Now.ToString("F");
     //2008 4 24  16:30
     System.DateTime.Now.ToString("f");
     //2008-4-24 16:30:15
     System.DateTime.Now.ToString("G");
     //2008-4-24 16:30
     System.DateTime.Now.ToString("g");
     //16:30:15
     System.DateTime.Now.ToString("T");
     //16:30
     System.DateTime.Now.ToString("t");
     //2008 4 24  8:30:15
     System.DateTime.Now.ToString("U");
     //2008-04-24 16:30:15Z
     System.DateTime.Now.ToString("u");
     //4 24 
     System.DateTime.Now.ToString("m");
     System.DateTime.Now.ToString("M");
     //Tue, 24 Apr 2008 16:30:15 GMT
     System.DateTime.Now.ToString("r");
     System.DateTime.Now.ToString("R");
     //2008 4 
     System.DateTime.Now.ToString("y");
     System.DateTime.Now.ToString("Y");
     //2008-04-24T15:52:19.1562500+08:00
     System.DateTime.Now.ToString("o");
     System.DateTime.Now.ToString("O");
     //2008-04-24T16:30:15
     System.DateTime.Now.ToString("s");
     //2008-04-24 15:52:19
     System.DateTime.Now.ToString("yyyy-MM-dd HH：mm：ss：ffff");
     //2008 04 24 15 56 48 
     System.DateTime.Now.ToString("yyyy MM dd HH mm ss ");
     //   ,    24 2008
     System.DateTime.Now.ToString("dddd, MMMM dd yyyy");
     // ,    24 '08
     System.DateTime.Now.ToString("ddd, MMM d \"'\"yy");
     //   ,    24
     System.DateTime.Now.ToString("dddd, MMMM dd");
     //4-08
     System.DateTime.Now.ToString("M/yy");
     //24-04-08
     System.DateTime.Now.ToString("dd-MM-yy");
    //          
.ToString("n");  //   12,345.00
.ToString("C"); //   ￥12,345.00
.ToString("e"); //   1.234500e+004
.ToString("f4"); //   12345.0000
.ToString("x"); //   3039 (16  )
.ToString("p"); //   1,234,500
     //      、     、       
  　//  
     DateTime.Now.Date.ToShortDateString();
     //  ，         
     DateTime.Now.AddDays(-1).ToShortDateString();
     //  ，  ，  
     DateTime.Now.AddDays(1).ToShortDateString();
     //  (                    ，                   ，                    
     DateTime.Now.AddDays(Convert.ToDouble((0 - Convert.ToInt16(DateTime.Now.DayOfWeek)))).ToShortDateString();
     DateTime.Now.AddDays(Convert.ToDouble((6 - Convert.ToInt16(DateTime.Now.DayOfWeek)))).ToShortDateString();
     //       ，                   
     //  DayOfWeek          ，                ，       switch        ，                      
     string[] Day = new string[]{ "   ", "   ", "   ", "   ", "   ", "   ", "   " };
     Day[Convert.ToInt16(DateTime.Now.DayOfWeek)];
     //  ，  ，    7 ，         7 ，      
     DateTime.Now.AddDays(Convert.ToDouble((0 - Convert.ToInt16(DateTime.Now.DayOfWeek))) - 7).ToShortDateString();
     DateTime.Now.AddDays(Convert.ToDouble((6 - Convert.ToInt16(DateTime.Now.DayOfWeek))) - 7).ToShortDateString();
     //  
     DateTime.Now.AddDays(Convert.ToDouble((0 - Convert.ToInt16(DateTime.Now.DayOfWeek))) + 7).ToShortDateString();
     DateTime.Now.AddDays(Convert.ToDouble((6 - Convert.ToInt16(DateTime.Now.DayOfWeek))) + 7).ToShortDateString();
     //  ,                1 ，               。      
     //     
     DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString() + "1"; //   
     DateTime.Parse(DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString() + "1").AddMonths(1).AddDays(-1).ToShortDateString();//    
     //  C# ToString         
     DateTime.Now.ToString("yyyy-MM-01");
     DateTime.Parse(DateTime.Now.ToString("yyyy-MM-01")).AddMonths(1).AddDays(-1).ToShortDateString();
     //   ，      
     DateTime.Parse(DateTime.Now.ToString("yyyy-MM-01")).AddMonths(-1).ToShortDateString();
     DateTime.Parse(DateTime.Now.ToString("yyyy-MM-01")).AddDays(-1).ToShortDateString();
     //   ，      
     DateTime.Parse(DateTime.Now.ToString("yyyy-MM-01")).AddMonths(1).ToShortDateString();
     DateTime.Parse(DateTime.Now.ToString("yyyy-MM-01")).AddMonths(2).AddDays(-1).ToShortDateString();
     //7  
     DateTime.Now.Date.ToShortDateString();
     DateTime.Now.AddDays(7).ToShortDateString();
     //7  
     DateTime.Now.AddDays(-7).ToShortDateString();
     DateTime.Now.Date.ToShortDateString();
     //   ， ToString                           
     DateTime.Parse(DateTime.Now.ToString("yyyy-01-01")).ToShortDateString();
     DateTime.Parse(DateTime.Now.ToString("yyyy-01-01")).AddYears(1).AddDays(-1).ToShortDateString();
     //   ，       
     DateTime.Parse(DateTime.Now.ToString("yyyy-01-01")).AddYears(-1).ToShortDateString();
     DateTime.Parse(DateTime.Now.ToString("yyyy-01-01")).AddDays(-1).ToShortDateString();
     //   
     DateTime.Parse(DateTime.Now.ToString("yyyy-01-01")).AddYears(1).ToShortDateString();
     DateTime.Parse(DateTime.Now.ToString("yyyy-01-01")).AddYears(2).AddDays(-1).ToShortDateString();
     //   ，           ，            。     ，           ，       
     //                 ，                   
     DateTime.Now.AddMonths(0 - ((DateTime.Now.Month - 1) % 22)).ToString("yyyy-MM-01");
     //  ，                   
     DateTime.Parse(DateTime.Now.AddMonths(22 - ((DateTime.Now.Month - 1) % 22)).ToString("yyyy-MM-01")).AddDays(-1).ToShortDateString();
     //   ，        。。。。  
     DateTime.Now.AddMonths(22 - ((DateTime.Now.Month - 1) % 22)).ToString("yyyy-MM-01");
     DateTime.Parse(DateTime.Now.AddMonths(6 - ((DateTime.Now.Month - 1) % 22)).ToString("yyyy-MM-01")).AddDays(-1).ToShortDateString();
     //   
     DateTime.Now.AddMonths(-22 - ((DateTime.Now.Month - 1) % 22)).ToString("yyyy-MM-01");
     DateTime.Parse(DateTime.Now.AddMonths(0 - ((DateTime.Now.Month - 1) % 22)).ToString("yyyy-MM-01")).AddDays(-1).ToShortDateString();