// 计算某个月有多少天
private void GetLastDateForMonth(DateTime DtStart, out DateTime DtEnd)
{
int Dtyear, DtMonth;
Dtyear = DtStart.Year;
DtMonth = DtStart.Month;
int MonthCount = DateTime.DaysInMonth(Dtyear, DtMonth);//計算該月有多少天
DtEnd = Convert.ToDateTime(Dtyear.ToString() + "-" + DtMonth.ToString() + "-" + MonthCount);
}
/// <summary>
/// 取得某月的最后一天
/// 方法二：取出下月的第一天減去一天便是這個月的最后一天
/// </summary>
/// <param name="DtStart"> </param>
/// <param name="DtEnd"> </param>
public static void GetLastDateForMonthEx(DateTime DtStart, out DateTime DtEnd)
{
int Dtyear, DtMonth;
DtStart = DateTime.Now.AddMonths(1); //月份加1
Dtyear = DtStart.Year;
DtMonth = DtStart.Month;
DtEnd = Convert.ToDateTime(Dtyear.ToString() + "-" + DtMonth.ToString() + "-" + "1").AddDays(-1);
//取出下月的第一天減去一天
}
/// <summary>
/// 获取月份的最后一天
/// </summary>
/// <param name="DayOfMonth">月份中的一天</param>
/// <returns>该月的最后一天</returns>
public static DateTime GetLastDateForMonth(DateTime DayOfMonth)
{
DateTime DtEnd;
int Dtyear, DtMonth;
Dtyear = DayOfMonth.Year;
DtMonth = DayOfMonth.Month;
int MonthCount = DateTime.DaysInMonth(Dtyear, DtMonth);//计算该月有多少天
DtEnd = Convert.ToDateTime(Dtyear.ToString() + "-" + DtMonth.ToString() + "-" + MonthCount);
DtEnd.AddDays(1).AddMilliseconds(-1);
return(DtEnd);
}