C# 如何判断两个日期不在同一周

public static int IsStartTask(string s_Task, DateTime LastTime)
        {
            int Ret = 0;
            DateTime ClockOfNow = DateTime.Now;
            int iYear = ClockOfNow.Year;
            int iMonth = ClockOfNow.Month;
            int iDay = ClockOfNow.Day;
            int iDayName = GetDayName(ClockOfNow.DayOfWeek);
            int iHour = ClockOfNow.Hour;
            int iMinute = ClockOfNow.Minute;
            int iSecond = ClockOfNow.Second;

            int Year = LastTime.Year;
            int Month = LastTime.Month;
            int Day = LastTime.Day;
            int DayName = GetDayName(LastTime.DayOfWeek);
            int Hour = LastTime.Hour;
            int Minute = LastTime.Minute;
            int Second = LastTime.Second;


            string sType, sTime, sValue;
            TimeSpan tTime, tNow;
            string[] ssValue = new String[10];

            tNow = TimeSpan.Parse(String.Format("{0}:{1}:{2}", iHour, iMinute, iSecond));

            bool Flag = false;
            int length = 0;
            int i = 0;

            sType = s_Task.Split('|')[0];
            sTime = s_Task.Split('|')[1];
            sValue = s_Task.Split('|')[2];
            if (sValue.Length > 1)
            {
                Flag = true;
                length = (sValue.Length + 1) / 2;
                for (i = 0; i < length; i++)
                    ssValue[i] = sValue.Split(',')[i];
            }
            if (sValue.Trim() == "")
                sValue = "0";
            tTime = TimeSpan.Parse(sTime);

            bool iFlag = false;

            switch (sType)
            {
                case "day":    //按天调度           
                    {

                        if (iYear == Year && iMonth == Month && iDay == Day)
                            iFlag = true;

                        if (tNow >= tTime && DateTime.Compare(ClockOfNow, LastTime) > 0 && !iFlag)
                            Ret = 1;
                        else
                            Ret = 0;
                        break;
                    }
                case "week":   //按周调度
                    {
                        if (Flag == false)
                        {
                            if (int.Parse(sValue) == iDayName)
                            {

                                TimeSpan ts = ClockOfNow - LastTime;
                                double db1 = ts.TotalDays;
                                int intDow = iDayName;
                                if (intDow == 0)
                                    intDow = 7;
                                if (db1 >= 7 || db1 >= intDow)
                                {
                                    if (tNow >= tTime)
                                    {
                                        Ret = 1;
                                    }
                                    else
                                    {
                                        Ret = 0;
                                    }
                                }
                                else
                                {
                                    Ret = 0;
                                }

                            }
                            else
                                Ret = 0;
                        }
                        else
                        {
                            bool jFlag = false;
                            for (i = 0; i < length; i++)
                                if (int.Parse(ssValue[i]) == iDayName)
                                {
                                    jFlag = true;
                                    break;
                                }
                            if (jFlag == true)
                            {
                                TimeSpan ts = ClockOfNow - LastTime;
                                double db1 = ts.TotalDays;
                                int intDow = iDayName;
                                if (intDow == 0)
                                    intDow = 7;
                                if (db1 >= 7 || db1 >= intDow)
                                {
                                    if (tNow >= tTime)
                                    {
                                        Ret = 1;
                                    }
                                    else
                                    {
                                        Ret = 0;
                                    }
                                }
                                else
                                {
                                    Ret = 0;
                                }
                            }
                            else
                            {
                                Ret = 0;
                            }

                        }
                        break;
                    }

                case "month": //按月调度
                    {
                        if (int.Parse(sValue) == iDay)
                        {
                            if (iYear == Year && iMonth == Month)
                                iFlag = true;
                            if (tNow >= tTime && !iFlag && DateTime.Compare(ClockOfNow, LastTime) > 0)
                                Ret = 1;
                            else
                                Ret = 0;

                        }
                        break;
                    }
                default: Ret = 0; break;
            }

            return Ret;
        }

 

2010 暑假--公司实习