C # computing time-determine the week by date and determine the date range by week

Using System;
Using System. Globalization;
Namespace ConvertDateTime
{
/// <Summary>
/// ConvertDateTime returns a brief description of the specified parameters.

/// </Summary>
Public class ConvertDate
{
Public ConvertDate ()
{}
//************************************** *****************************//
# Region determines the current day of the week based on the current date
Public static string GetWeekDay (string strDate)
{
Try
{
// Time To be determined
DateTime dTime = Convert. ToDateTime (strDate );

Return GetWeekDay (dTime );
}
Catch (Exception ex)
{
Throw new Exception (ex. Message );
}

}
Public static string GetWeekDay (DateTime dTime)
{
Try
{
// Determine the day of the week
Int index = (int) dTime. DayOfWeek;
Return GetWeekDay (index );
}
Catch (Exception ex)
{
Throw new Exception (ex. Message );
}

}
# Endregion

//************************************** *****************************//
# Region obtain the maximum number of weeks in the current year
Public static int GetMaxWeekOfYear (int year)
{
Try
{
DateTime tempDate = new DateTime (year, 12, 31 );
Int tempDayOfWeek = (int) tempDate. DayOfWeek;
If (tempDayOfWeek! = 0)
{
TempDate = tempDate. Date. AddDays (-tempDayOfWeek );
}
Return GetWeekIndex (tempDate );
}
Catch (Exception ex)
{
Throw new Exception (ex. Message );
}
}
Public static int GetMaxWeekOfYear (DateTime dTime)
{
Try
{
Return GetMaxWeekOfYear (dTime. Year );
}
Catch (Exception ex)
{
Throw new Exception (ex. Message );
}
}
# Endregion

//************************************** *****************************//
# Region obtain the week number based on the time

// If the year December 31 and the year January 1 are the same week, the first week of the year is counted.
Public static int GetWeekIndex (DateTime dTime)
{
Try
{
// Time To be determined
// DateTime dTime = Convert. ToDateTime (strDate );
// Determine the position of the time in one year
Int dayOfYear = dTime. DayOfYear;

// DateTime tempDate = new DateTime (dTime. Year, 1, 6, calendar );
// The first day of the current year
DateTime tempDate = new DateTime (dTime. Year, 1, 1 );

// Confirm the first day of the current year
Int tempDayOfWeek = (int) tempDate. DayOfWeek;
TempDayOfWeek = 0? 7: tempDayOfWeek;
// Determine the day of the week
Int index = (int) dTime. DayOfWeek;

Index = 0? 7: index;

// The range of the current week
DateTime retStartDay = dTime. AddDays (-(index-1 ));
DateTime retEndDay = dTime. AddDays (7-index );

// Determine the week
Int weekIndex = (int) Math. Ceiling (double) dayOfYear + tempDayOfWeek-1)/7 );

If (retStartDay. Year <retEndDay. Year)
{
WeekIndex = 1;
}

Return weekIndex;
}
Catch (Exception ex)
{
Throw new Exception (ex. Message );
}
// String retVal = retStartDay. ToString ("yyyy/MM/dd") + "~ "+ RetEndDay. ToString (" yyyy/MM/dd ");

}
Public static int GetWeekIndex (string strDate)
{
Try
{
// Time To be determined
DateTime dTime = Convert. ToDateTime (strDate );
Return GetWeekIndex (dTime );
}
Catch (Exception ex)
{
Throw new Exception (ex. Message );
}

}
# Endregion

//************************************** *****************************//
# Region obtain the date range of the week based on the time

Public static string GetWeekRange (string strDate)
{
Try
{
// Time To be determined
DateTime dTime = Convert. ToDateTime (strDate );
Return GetWeekRange (dTime );
}
Catch (Exception ex)
{
Throw new Exception (ex. Message );
}
}
Public static string GetWeekRange (DateTime dTime)
{
Try
{
Int index = (int) dTime. DayOfWeek;

Index = 0? 7: index;

// The range of the current week
DateTime retStartDay = dTime. AddDays (-(index-1 ));
DateTime retEndDay = dTime. AddDays (7-index );

Return WeekRangeToString (retStartDay, retEndDay );
}
Catch (Exception ex)
{
Throw new Exception (ex. Message );
}

}

Public static string GetWeekRange (int year, int weekIndex)
{
Try
{
If (weekIndex <1)
{
Throw new Exception ("enter an integer greater than 0 ");
}

Int allDays = (weekIndex-1) * 7;
// Confirm the first day of the current year
DateTime firstDate = new DateTime (year, 1, 1 );
Int firstDayOfWeek = (int) firstDate. DayOfWeek;

FirstDayOfWeek = 0? 7: firstDayOfWeek;

// Week start day
Int startAddDays = allDays + (1-firstDayOfWeek );
DateTime weekRangeStart = firstDate. AddDays (startAddDays );
// End day of the week
Int endAddDays = allDays + (7-firstDayOfWeek );
DateTime weekRangeEnd = firstDate. AddDays (endAddDays );

If (weekRangeStart. Year> year |
(WeekRangeStart. Year = year & weekRangeEnd. Year> year ))
{
Throw new Exception ("No Week" + weekIndex + "this year. ");
}

Return WeekRangeToString (weekRangeStart, weekRangeEnd );
}
Catch (Exception ex)
{
Throw new Exception (ex. Message );
}
}
Public static string GetWeekRange (int weekIndex)
{
Try
{
Return GetWeekRange (DateTime. Now. Year, weekIndex );
}
Catch (Exception ex)
{
Throw new Exception (ex. Message );
}
}

Private static string WeekRangeToString (DateTime weekRangeStart, DateTime weekRangeEnd)
{
String strWeekRangeStart = weekRangeStart. ToString ("yyyy/MM/dd ");
String strWeekRangeend = weekRangeEnd. AddDays. ToString ("yyyy/MM/dd ");

Return strWeekRangeStart + "~ "+ StrWeekRangeend;

}
# Endregion

//************************************** *****************************//
# Region expression of the week

Private static string GetWeekDay (int index)
{
String retVal = string. Empty;
Switch (index)
{
Case 0:
{
RetVal = "Sunday ";
Break;
}
Case 1:
{
RetVal = "Monday ";
Break;
}
Case 2:
{
RetVal = "Tuesday ";
Break;
}
Case 3:
{
RetVal = "Wednesday ";
Break;
}
Case 4:
{
RetVal = "Thursday ";
Break;
}
Case 5:
{
RetVal = "Friday ";
Break;
}
Case 6:
{
RetVal = "Saturday ";
Break;
}
}

Return retVal;
}
# Endregion
}
}