用于查询的日期类型转换帮助类
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。
三、代码及下载
/*
*
* 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
}
}