求大神帮忙解决日期控件问题
string myStrYear, myStrMonth, myStrDay, myStrDay1;
             string myStrFileName = "";
             myStrYear = myDTTime.Year.ToString().Substring(2, 2);
             if (myDTTime.Month > 9)
             {
                 myStrMonth = myDTTime.Month.ToString();
             }
             else
             {
                 myStrMonth = "0" + myDTTime.Month.ToString();
             }
             if (myDTTime.Day > 9)
             {
                 myStrDay = myDTTime.Day.ToString();
             }
             else
             {
                 myStrDay = "0" + myDTTime.Day.ToString();
             }
             d = Convert.ToInt32(myStrDay) - 1;
             myStrDay1 =  Convert.ToString(d);
             myStrFileName = myStrYear + myStrMonth + myStrDay1 ;
------解决方案--------------------比如:
C# code
DateTime tody = DateTime.Now;
DateTime yesdy = tody.AddDays(-1);
Console.WriteLine(yesdy.ToString());
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------解决方案--------------------
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[code=C#][/code]
DateTime dt=DateTime.Now;
//前一天  
dt.AddDays(-1);
//前一周  
dt.AddDays(-7);
//前一月  
dt.AddMonths(-1);
//前一年  
dt.AddYears(-1);