请教C#中如何取到当前日期是在一年中的第几周

请问C#中怎么取到当前日期是在一年中的第几周
请问C#中怎么取到当前日期是在一年中的第几周

[解决办法]
private int WeekOfYear(string date)
{
DateTime curDay = Convert.ToDateTime(date);

int firstdayofweek = Convert.ToInt32(Convert.ToDateTime(curDay.Year.ToString() + "- " + "1-1 ").DayOfWeek);

int days = curDay.DayOfYear;
int daysOutOneWeek = days - (7 - firstdayofweek);

if (daysOutOneWeek <= 0)
{
return 1;
}
else
{
int weeks = daysOutOneWeek / 7;
if (daysOutOneWeek % 7 != 0)
weeks ++;

return weeks + 1;
}
}
这是我写的