已知月日计算周次

当前周次

DateTimedtime=Convert.ToDateTime(TextBox2.Text);

DateTimedtime=DateTime.Now;

intweeknum=0;

DateTimetmpdate=DateTime.Parse(dtime.Year.ToString()+"-1"+"-1");

DayOfWeekfirstweek=tmpdate.DayOfWeek;

//if(firstweek)

for(inti=(int)firstweek+1;i<=dtime.DayOfYear;i=i+7)

{

weeknum=weeknum+1;

}

inta=weeknum;



一年总周次

stringtime=DateTime.Now.ToString();

string[]tmil=time.Split('''');

string[]tmi=tmil[0].Split(''-'');

stringreturnStr="";

stringstrYear=tmi[0];

System.DateTimefDt=DateTime.Parse(strYear+"-01-01");

intk=Convert.ToInt32(fDt.DayOfWeek);//得到该年的第一天是周几

if(k==1)

{

intcountDay=fDt.AddYears(1).AddDays(-1).DayOfYear;

intcountWeek=countDay/7+1;

//returncountWeek;



}

else

{

intcountDay=fDt.AddYears(1).AddDays(-1).DayOfYear;

intcountWeek=countDay/7+2;

//returncountWeek;

}