本文转载：http://www.cnblogs.com/iamlilinfeng/p/3378659.html
1.按指定日期查询
（1）用户在UI上选择日期;
（2）系统计算出今天的起始时间(****年**月**日 00:00:00)和今天的结束时间(****年**月**日 23:59:59);
（3）系统根据根据该日期范围到数据库取出该日期范围的数据。
/* * * 创建人：李林峰 * * 时 间：2009-05-04 * * 描 述：日期转换帮助类，常用于报表开发; * 可以转换成为：本日开始时间、本日结束时间、本周开始时间、本周结束时间、本月开始时间、本月结束时间、本年开始时间、本年结束时间 * */using
System;namespace
SongCai8.WebSite{ /// <summary> /// 日期转换帮助类 /// </summary> public
static class DateTimeHelper { #region 日 /// <summary> /// 将日期转换为本日的开始时间 /// </summary> /// <param name="value">2001-01-01</param> /// <returns>2001-01-01 00:00:00</returns> public
static DateTime ToDayStart(string
value) { //转换成日期类型 DateTime date = System.Convert.ToDateTime(value); //转换成短日期类型字符 string
shortDate = date.ToShortDateString(); //返回日期类型 return
System.Convert.ToDateTime(shortDate); } /// <summary> /// 将日期转换为本日的开始时间 /// </summary> /// <param name="value">任意时间</param> /// <returns>2001-01-01 00:00:00</returns> public
static DateTime ToDayStart(DateTime value) { //转换成短日期类型字符 string
shortDate = value.ToShortDateString(); //返回日期类型 return
System.Convert.ToDateTime(shortDate); } /// <summary> /// 将日期转换为本日的开始时间 /// </summary> /// <param name="value">2001-01-01</param> /// <returns>2001-01-01 23:59:59</returns> public
static DateTime ToDayEnd(string
value) { //转换成日期类型 DateTime date = System.Convert.ToDateTime(value); //转换成短日期类型 DateTime shortDate = System.Convert.ToDateTime(date.ToShortDateString()); //返回日期加一天减一秒 return
shortDate.AddDays(1).AddSeconds(-1); } /// <summary> /// 将日期转换为本日的结束时间 /// </summary> /// <param name="value">任意时间</param> /// <returns>2001-01-01 23:59:59</returns> public
static DateTime ToDayEnd(DateTime value) { //转换成短日期类型 DateTime shortDate = System.Convert.ToDateTime(value.ToShortDateString()); //返回日期加一天减一秒 return
shortDate.AddDays(1).AddSeconds(-1); } #endregion #region 周 /// <summary> /// 将日期转换为本周的开始时间 /// </summary> /// <param name="value">2001-01-01</param> /// <returns>2001-01-01 00:00:00</returns> public
static DateTime ToWeekStart(string
value) { //转换成日期类型 DateTime date = System.Convert.ToDateTime(value); //根据当前时间取出该周周一的当前时间 DateTime weekStart = ToWeekStart(date, date.Date.DayOfWeek); //转换成短日期类型字符 string
shortDate = weekStart.ToShortDateString(); //返回日期类型 return
System.Convert.ToDateTime(shortDate); } /// <summary> /// 将日期转换为本周的开始时间 /// </summary> /// <param name="value">任意时间</param> /// <returns>2001-01-01 00:00:00</returns> public
static DateTime ToWeekStart(DateTime value) { //根据当前时间取出该周周一的当前时间 DateTime weekStart = ToWeekStart(value, value.Date.DayOfWeek); //转换成短日期类型字符 string
shortDate = weekStart.ToShortDateString(); //返回日期类型 return
System.Convert.ToDateTime(shortDate); } /// <summary> /// 将日期转换为本周的结束时间 /// </summary> /// <param name="value">2001-01-01</param> /// <returns>2001-01-01 23:59:59</returns> public
static DateTime ToWeekEnd(string
value) { //转换成日期类型 DateTime date = System.Convert.ToDateTime(value); //根据当前时间取出该周周末的当前时间 DateTime weekEnd = ToWeekEnd(date, date.Date.DayOfWeek); //转换成短日期类型字符 string
shortDate = weekEnd.ToShortDateString(); //返回日期加一天减一秒 return
Convert.ToDateTime(shortDate).AddDays(1).AddSeconds(-1); } /// <summary> /// 将日期转换为本周的结束时间 /// </summary> /// <param name="value">任意时间</param> /// <returns>2001-01-01 23:59:59</returns> public
static DateTime ToWeekEnd(DateTime value) { //根据当前时间取出该周周末的当前时间 DateTime weekEnd = ToWeekEnd(value, value.Date.DayOfWeek); //转换成短日期类型字符 string
shortDate = weekEnd.ToShortDateString(); //返回日期类型 //返回日期加一天减一秒 return
Convert.ToDateTime(shortDate).AddDays(1).AddSeconds(-1); } /// <summary> /// 将日期转换为本周周一的某一时间 /// </summary> /// <param name="date">将要转换的日期</param> /// <param name="week">传入日期的周的枚举类型</param> /// <returns>2001-01-01 12:12:12</returns> private
static DateTime ToWeekStart(DateTime date, DayOfWeek week) { DateTime WeekStart = new
DateTime(); switch
(week) { case
DayOfWeek.Monday: WeekStart = date; break; case
DayOfWeek.Tuesday: WeekStart = date.AddDays(-1); break; case
DayOfWeek.Wednesday: WeekStart = date.AddDays(-2); break; case
DayOfWeek.Thursday: WeekStart = date.AddDays(-3); break; case
DayOfWeek.Friday: WeekStart = date.AddDays(-4); break; case
DayOfWeek.Saturday: WeekStart = date.AddDays(-5); break; case
DayOfWeek.Sunday: WeekStart = date.AddDays(-6); break; } return
WeekStart; } /// <summary> /// 将日期转换为本周周日的某一时间 /// </summary> /// <param name="date">将要转换的日期</param> /// <param name="week">传入日期的周的枚举类型</param> /// <returns>2001-01-01 12:12:12</returns> private
static DateTime ToWeekEnd(DateTime date, DayOfWeek week) { DateTime WeekStart = new
DateTime(); switch
(week) { case
DayOfWeek.Monday: WeekStart = date.AddDays(6); break; case
DayOfWeek.Tuesday: WeekStart = date.AddDays(5); break; case
DayOfWeek.Wednesday: WeekStart = date.AddDays(4); break; case
DayOfWeek.Thursday: WeekStart = date.AddDays(3); break; case
DayOfWeek.Friday: WeekStart = date.AddDays(2); break; case
DayOfWeek.Saturday: WeekStart = date.AddDays(1); break; case
DayOfWeek.Sunday: WeekStart = date; break; } return
WeekStart; } #endregion #region 月 /// <summary> /// 将日期转换为本月的开始时间 /// </summary> /// <param name="value">2001-01-01</param> /// <returns>2001-01-01 00:00:00</returns> public
static DateTime ToMonthStart(string
value) { //转换成日期类型 DateTime date = System.Convert.ToDateTime(value); //根据年、月重新创建日期 return
new DateTime(date.Year, date.Month, 1); } /// <summary> /// 将日期转换为本月的开始时间 /// </summary> /// <param name="value">任意时间</param> /// <returns>2001-01-01 00:00:00</returns> public
static DateTime ToMonthStart(DateTime value) { //根据年、月重新创建日期 return
new DateTime(value.Year, value.Month, 1); } /// <summary> /// 将日期转换为本月的结束时间 /// </summary> /// <param name="value">2001-01-01</param> /// <returns>2001-01-31 23:59:59</returns> public
static DateTime ToMonthEnd(string
value) { //转换成日期类型 DateTime date = System.Convert.ToDateTime(value); //根据年、月重新创建日期 DateTime monthStart = new
DateTime(date.Year, date.Month, 1); //创建结束日期 return
monthStart.AddMonths(1).AddSeconds(-1); } /// <summary> /// 将日期转换为本月的结束时间 /// </summary> /// <param name="value">任意时间</param> /// <returns>2001-01-31 23:59:59</returns> public
static DateTime ToMonthEnd(DateTime value) { //根据年、月重新创建日期 DateTime monthStart = new
DateTime(value.Year, value.Month, 1); //创建结束日期 return
monthStart.AddMonths(1).AddSeconds(-1); } #endregion #region 年 /// <summary> /// 将日期转换为本年的开始时间 /// </summary> /// <param name="value">2001-01-01</param> /// <returns>2001-01-01 00:00:00</returns> public
static DateTime ToYearStart(string
value) { //转换成日期类型 DateTime date = System.Convert.ToDateTime(value); //根据年、月重新创建日期 return
new DateTime(date.Year, 1, 1); } /// <summary> /// 将日期转换为本年的开始时间 /// </summary> /// <param name="value">任意时间</param> /// <returns>2001-01-01 00:00:00</returns> public
static DateTime ToYearStart(DateTime value) { //根据年、月重新创建日期 return
new DateTime(value.Year, 1, 1); } /// <summary> /// 将日期转换为本年的结束时间 /// </summary> /// <param name="value">2001-01-01</param> /// <returns>2001-12-31 23:59:59</returns> public
static DateTime ToYearEnd(string
value) { //转换成日期类型 DateTime date = System.Convert.ToDateTime(value); //根据年、月重新创建日期 DateTime yearStart = new
DateTime(date.Year, 1, 1); //创建结束日期 DateTime yearEnd = new
DateTime(date.Year, 1, 1).AddYears(1).AddSeconds(-1); return
yearEnd; } /// <summary> /// 将日期转换为本年的结束时间 /// </summary> /// <param name="value">任意时间</param> /// <returns>2001-12-31 23:59:59</returns> public
static DateTime ToYearEnd(DateTime value) { //根据年、月重新创建日期 DateTime yearStart = new
DateTime(value.Year, 1, 1); //创建结束日期 return
new DateTime(value.Year, 1, 1).AddYears(1).AddSeconds(-1); } #endregion }} |
原文：http://www.cnblogs.com/zfanlong1314/p/3573667.html