DateDiff

悠悠 2022-04-01 13:37 186阅读 0赞

using System;  
using System.Collections.Generic;  
using System.Text;  
  
namespace IntrBar  
\{  
public enum DateInterval  
\{  
Day,  
DayOfYear,  
Hour,  
Minute,  
Month,  
Quarter,  
Second,  
Weekday,  
WeekOfYear,  
Year  
\}  
  
public class DateAndTime  
\{  
public static long DateDiff(DateInterval interval, DateTime dt1, DateTime dt2)  
\{  
return DateDiff(interval, dt1, dt2, System.Globalization.DateTimeFormatInfo.CurrentInfo.FirstDayOfWeek);  
\}  
  
private static int GetQuarter(int nMonth)  
\{  
if (nMonth <= 3)  
return 1;  
if (nMonth <= 6)  
return 2;  
if (nMonth <= 9)  
return 3;  
return 4;  
\}  
  
public static long DateDiff(DateInterval interval, DateTime dt1, DateTime dt2, DayOfWeek eFirstDayOfWeek)  
\{  
if (interval == DateInterval.Year)  
return dt2.Year - dt1.Year;  
  
if (interval == DateInterval.Month)  
return (dt2.Month - dt1.Month) + (12 \* (dt2.Year - dt1.Year));  
  
TimeSpan ts = dt2 - dt1;  
  
if (interval == DateInterval.Day || interval == DateInterval.DayOfYear)  
return Round(ts.TotalDays);  
  
if (interval == DateInterval.Hour)  
return Round(ts.TotalHours);  
  
if (interval == DateInterval.Minute)  
return Round(ts.TotalMinutes);  
  
if (interval == DateInterval.Second)  
return Round(ts.TotalSeconds);  
  
if (interval == DateInterval.Weekday)  
\{  
return Round(ts.TotalDays / 7.0);  
\}  
  
if (interval == DateInterval.WeekOfYear)  
\{  
while (dt2.DayOfWeek != eFirstDayOfWeek)  
dt2 = dt2.AddDays(-1);  
while (dt1.DayOfWeek != eFirstDayOfWeek)  
dt1 = dt1.AddDays(-1);  
ts = dt2 - dt1;  
return Round(ts.TotalDays / 7.0);  
\}  
  
if (interval == DateInterval.Quarter)  
\{  
double d1Quarter = GetQuarter(dt1.Month);  
double d2Quarter = GetQuarter(dt2.Month);  
double d1 = d2Quarter - d1Quarter;  
double d2 = (4 \* (dt2.Year - dt1.Year));  
return Round(d1 + d2);  
\}  
  
return 0;  
  
\}  
  
private static long Round(double dVal)  
\{  
if (dVal >= 0)  
return (long)Math.Floor(dVal);  
return (long)Math.Ceiling(dVal);  
\}  
\}  
\}