[转]C#根据当前时间确定日期范围（本周、本月、本季度、本年度及常见日期方法荟萃 - 岁末年初

标签：00 C# AddDays System DateTime 本季度 日期 date dt

DateTime dt = DateTime.Now;  //当前时间DateTime startWeek = dt.AddDays(1 - Convert.ToInt32(dt.DayOfWeek.ToString("d")));  //本周周一DateTime endWeek = startWeek.AddDays(6);  //本周周日DateTime startMonth = dt.AddDays(1 - dt.Day);  //本月月初DateTime endMonth = startMonth.AddMonths(1).AddDays(-1);  //本月月末//DateTime endMonth = startMonth.AddDays((dt.AddMonths(1) - dt).Days - 1);  //本月月末DateTime startQuarter = dt.AddMonths(0 - (dt.Month - 1) % 3).AddDays(1 - dt.Day);  //本季度初DateTime endQuarter = startQuarter.AddMonths(3).AddDays(-1);  //本季度末DateTime startYear = new DateTime(dt.Year, 1, 1);  //本年年初DateTime endYear = new DateTime(dt.Year, 12, 31);  //本年年末

昨天、明天、上周、上月、上季度、上年度等等，只要AddDays()、AddMonths()、AddYears()这几种方法组合

一.如何获得当月有多少天

int m=System.DateTime.DaysInMonth(System.DateTime.Now.Year,System.DateTime.Now.Month);

二.日期型格式处理通用方法
1.在webconfig中配置如下

<add key="ShortDatePattern" value="MM-dd-yyyy" /><add key="LongDatePattern" value="dddd-MMMM dd-yyyy" /><add key="ShortTimePattern" value="hh:mm tt" /><add key="LongTimePattern" value="hh:mm tt" />2.在global.asax中

protected void Application_BeginRequest(Object sender, EventArgs e){Thread currentThread = Thread.CurrentThread;CultureInfo cul = currentThread.CurrentCulture.Clone() as CultureInfo;cul.DateTimeFormat.ShortDatePattern= BLLFacade.Common.GetShortDatePattern();cul.DateTimeFormat.LongDatePattern= BLLFacade.Common.GetLongDatePattern();cul.DateTimeFormat.ShortTimePattern= BLLFacade.Common.GetShortTimePattern();cul.DateTimeFormat.LongTimePattern= BLLFacade.Common.GetLongTimePattern();currentThread.CurrentCulture = cul;}

3.在业务逻辑层中

public static string GetShortDatePattern(){return System.Configuration.ConfigurationSettings.AppSettings["ShortDatePattern"];}public static string GetLongDatePattern(){return System.Configuration.ConfigurationSettings.AppSettings["LongDatePattern"];}public static string GetShortTimePattern(){return System.Configuration.ConfigurationSettings.AppSettings["ShortTimePattern"];}public static string GetLongTimePattern(){return System.Configuration.ConfigurationSettings.AppSettings["LongTimePattern"];}

4.然后在其他地方正常调用就可以了，如果需要修改格式只需要修改webconfig中的，且可以保证整个系统中的所有格式都是一致的
三.在asp.net中怎么样计算两个日期相差的年、月份、日期、小时、分钟 、妙等
在asp.net中怎么样计算两个日期相差的年、月份、日期、小时、分钟 、妙等#region 在asp.net中怎么样计算两个日期相差的年、月份、日期、小时、分钟 、妙等
// 调用

//        DateTime a=Convert.ToDateTime("2005-09-03 20:15");//        DateTime b=Convert.ToDateTime("2005-09-04 09:09 ");//        double d=Bll.Common.DateDiff(Bll.Common.EnumDateCompare.day,a,b);//        Response.Write(d.ToString("f0"));//四舍五入        public enum EnumDateCompare        {            year    =1,            month    =2,            day        =3,            hour    =4,            minute    =5,            second    =6        }        public static double DateDiff(EnumDateCompare howtocompare, System.DateTime startDate, System.DateTime endDate)        {            double diff=0;            System.TimeSpan TS = new System.TimeSpan(endDate.Ticks-startDate.Ticks);            switch (howtocompare)            {                case EnumDateCompare.year:                    diff = Convert.ToDouble(TS.TotalDays/365);                    break;                case EnumDateCompare.month:                    diff = Convert.ToDouble((TS.TotalDays/365)*12);                    break;                case EnumDateCompare.day:                    diff = Convert.ToDouble(TS.TotalDays);                    break;                case EnumDateCompare.hour:                    diff = Convert.ToDouble(TS.TotalHours);                    break;                case EnumDateCompare.minute:                    diff = Convert.ToDouble(TS.TotalMinutes);                    break;                case EnumDateCompare.second:                    diff = Convert.ToDouble(TS.TotalSeconds);                    break;            }            return diff;        }

四.获取某月的实际工作日(即不包括周六日)
//调用

//int days =getDays(System.DateTime.Now));private int getDays(System.DateTime date1){    int m=System.DateTime.DaysInMonth(date1.Year,date1.Month);    int mm=0;    for(int i=1;i<=m;i++)    {        System.DateTime date=Convert.ToDateTime(date1.Year+"-"+date1.Month+"-"+i);        switch (date.DayOfWeek)        {            case System.DayOfWeek.Monday:            case System.DayOfWeek.Thursday:            case System.DayOfWeek.Tuesday:            case System.DayOfWeek.Wednesday:            case System.DayOfWeek.Friday:                mm=mm+1;                break;        }    }    return mm;}

五.获得任意两日期之间的有效工作日(不包括周六日) 获得任意两日期之间的有效工作日(不包括周六日)#region 获得任意两日期之间的有效工作日(不包括周六日)
//调用

        //DateTime date1=Convert.ToDateTime("2005-10-20");        //DateTime date2=Convert.ToDateTime("2005-11-01");        //int days =getDays(date1,date2);        private int getDays(System.DateTime date1,System.DateTime date2)        {            string m=DateDiff(EnumDateCompare.day,date1,date2).ToString("f0");            int mm=0;            for(int i=0;i<=Convert.ToInt32(m);i++)            {                System.DateTime date=Convert.ToDateTime(date1.AddDays(i));                switch (date.DayOfWeek)                {                    case System.DayOfWeek.Monday:                    case System.DayOfWeek.Thursday:                    case System.DayOfWeek.Tuesday:                    case System.DayOfWeek.Wednesday:                    case System.DayOfWeek.Friday:                        mm=mm+1;                        break;                }            }            return mm;        }

六.格式输出
格式输出#region 格式输出

        private void Page_Load(object sender, System.EventArgs e)        {            System.Globalization.DateTimeFormatInfo myDTFI = new System.Globalization.CultureInfo( "en-US", false ).DateTimeFormat;//中国用zh-cn            DateTime myDT =System.DateTime.Now;            Response.Write(myDT.ToString("f",myDTFI));            /**//**//**//*            This code produces the following output.            FORMAT  en-US EXAMPLE            CHAR    VALUE OF ASSOCIATED PROPERTY, IF ANY              d     1/3/2002                    M/d/yyyy (ShortDatePattern)              D     Thursday, January 03, 2002                    dddd, MMMM dd, yyyy (LongDatePattern)              f     Thursday, January 03, 2002 12:00 AM              F     Thursday, January 03, 2002 12:00:00 AM                    dddd, MMMM dd, yyyy h:mm:ss tt (FullDateTimePattern)              g     1/3/2002 12:00 AM              G     1/3/2002 12:00:00 AM              m     January 03                    MMMM dd (MonthDayPattern)              M     January 03                    MMMM dd (MonthDayPattern)              r     Thu, 03 Jan 2002 00:00:00 GMT                    ddd, dd MMM yyyy HH':'mm':'ss 'GMT' (RFC1123Pattern)              R     Thu, 03 Jan 2002 00:00:00 GMT                    ddd, dd MMM yyyy HH':'mm':'ss 'GMT' (RFC1123Pattern)              s     2002-01-03T00:00:00                    yyyy'-'MM'-'dd'T'HH':'mm':'ss (SortableDateTimePattern)              t     12:00 AM                    h:mm tt (ShortTimePattern)              T     12:00:00 AM                    h:mm:ss tt (LongTimePattern)              u     2002-01-03 00:00:00Z                    yyyy'-'MM'-'dd HH':'mm':'ss'Z' (UniversalSortableDateTimePattern)              U     Thursday, January 03, 2002 8:00:00 AM              y     January, 2002                    MMMM, yyyy (YearMonthPattern)              Y     January, 2002                    MMMM, yyyy (YearMonthPattern)            */        }

七.获得本周的周六和周日

ConvertDateToWeek#region ConvertDateToWeek        public static void ConvertDateToWeek(DateTime date,out DateTime firstdate,out DateTime lastdate)        {            DateTime first=System.DateTime.Now;            DateTime last=System.DateTime.Now;            switch (date.DayOfWeek)            {                case System.DayOfWeek.Monday:                    first=date.AddDays(-1);                    last=date.AddDays(5);                    break;                case System.DayOfWeek.Tuesday:                    first=date.AddDays(-2);                    last=date.AddDays(4);                    break;                case System.DayOfWeek.Wednesday:                    first=date.AddDays(-3);                    last=date.AddDays(3);                    break;                case System.DayOfWeek.Thursday:                    first=date.AddDays(-4);                    last=date.AddDays(2);                    break;                case System.DayOfWeek.Friday:                    first=date.AddDays(-5);                    last=date.AddDays(1);                    break;                case System.DayOfWeek.Saturday:                    first=date.AddDays(-6);                    last=date;                    break;                case System.DayOfWeek.Sunday:                    first=date;                    last=date.AddDays(6);                    break;            }            firstdate=first;            lastdate=last;        }        #endregion

//调用

DateTime firstdate=System.DateTime.Now;DateTime lastdate=System.DateTime.Now;ConvertDateToWeek(date,out firstdate,out lastdate);八获得当前日期是该年度的第几周DateTime dt = Convert.ToDateTime("2006-05-01");int weeks = dt.DayOfYear / 7 + 1;

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作者：岁末年初
来源：CNBLOGS
原文：https://www.cnblogs.com/xptopsky/p/16385220.html
版权声明：本文为作者原创文章，转载请附上博文链接！
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标签：00,C#,AddDays,System,DateTime,本季度,日期,date,dt
From： https://www.cnblogs.com/kevinl/p/16954987.html