【强烈推荐】开源C#工具类MSCL系列（七）Date时间日期帮助类

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

namespace MSCL
{
/// <summary>
/// 时间日期处理类
/// </summary>
public class DateHelper
{

#region 返回本年有多少天
/// <summary>返回本年有多少天</summary>
/// <param name="iYear">年份</param>
/// <returns>本年的天数</returns>
public static int GetDaysOfYear(int iYear)
{
int cnt = 0;
if (IsRuYear(iYear))
{
//闰年多 1 天 即：2 月为 29 天
cnt = 366;

}
else
{
//--非闰年少1天 即：2 月为 28 天
cnt = 365;
}
return cnt;
}
#endregion

#region 返回本年有多少天
/// <summary>本年有多少天</summary>
/// <param name="dt">日期</param>
/// <returns>本天在当年的天数</returns>
public static int GetDaysOfYear(DateTime idt)
{
int n;

//取得传入参数的年份部分，用来判断是否是闰年

n = idt.Year;
if (IsRuYear(n))
{
//闰年多 1 天 即：2 月为 29 天
return 366;
}
else
{
//--非闰年少1天 即：2 月为 28 天
return 365;
}

}
#endregion

#region 返回本月有多少天
/// <summary>本月有多少天</summary>
/// <param name="iYear">年</param>
/// <param name="Month">月</param>
/// <returns>天数</returns>
public static int GetDaysOfMonth(int iYear, int Month)
{
int days = 0;
switch (Month)
{
case 1:
days = 31;
break;
case 2:
if (IsRuYear(iYear))
{
//闰年多 1 天 即：2 月为 29 天
days = 29;
}
else
{
//--非闰年少1天 即：2 月为 28 天
days = 28;
}

break;
case 3:
days = 31;
break;
case 4:
days = 30;
break;
case 5:
days = 31;
break;
case 6:
days = 30;
break;
case 7:
days = 31;
break;
case 8:
days = 31;
break;
case 9:
days = 30;
break;
case 10:
days = 31;
break;
case 11:
days = 30;
break;
case 12:
days = 31;
break;
}

return days;
}
#endregion

#region 返回本月有多少天
/// <summary>本月有多少天</summary>
/// <param name="dt">日期</param>
/// <returns>天数</returns>
public static int GetDaysOfMonth(DateTime dt)
{
//--------------------------------//
//--从dt中取得当前的年，月信息  --//
//--------------------------------//
int year, month, days = 0;
year = dt.Year;
month = dt.Month;

//--利用年月信息，得到当前月的天数信息。
switch (month)
{
case 1:
days = 31;
break;
case 2:
if (IsRuYear(year))
{
//闰年多 1 天 即：2 月为 29 天
days = 29;
}
else
{
//--非闰年少1天 即：2 月为 28 天
days = 28;
}

break;
case 3:
days = 31;
break;
case 4:
days = 30;
break;
case 5:
days = 31;
break;
case 6:
days = 30;
break;
case 7:
days = 31;
break;
case 8:
days = 31;
break;
case 9:
days = 30;
break;
case 10:
days = 31;
break;
case 11:
days = 30;
break;
case 12:
days = 31;
break;
}

return days;

}
#endregion

#region 返回当前日期的星期名称
/// <summary>返回当前日期的星期名称</summary>
/// <param name="dt">日期</param>
/// <returns>星期名称</returns>
public static string GetWeekNameOfDay(DateTime idt)
{
string dt, week = "";

dt = idt.DayOfWeek.ToString();
switch (dt)
{
case "Mondy":
week = "星期一";
break;
case "Tuesday":
week = "星期二";
break;
case "Wednesday":
week = "星期三";
break;
case "Thursday":
week = "星期四";
break;
case "Friday":
week = "星期五";
break;
case "Saturday":
week = "星期六";
break;
case "Sunday":
week = "星期日";
break;

}
return week;
}
#endregion

#region 返回当前日期的星期编号
/// <summary>返回当前日期的星期编号</summary>
/// <param name="dt">日期</param>
/// <returns>星期数字编号</returns>
public static string GetWeekNumberOfDay(DateTime idt)
{
string dt, week = "";

dt = idt.DayOfWeek.ToString();
switch (dt)
{
case "Mondy":
week = "1";
break;
case "Tuesday":
week = "2";
break;
case "Wednesday":
week = "3";
break;
case "Thursday":
week = "4";
break;
case "Friday":
week = "5";
break;
case "Saturday":
week = "6";
break;
case "Sunday":
week = "7";
break;

}

return week;

}
#endregion

#region 判断当前日期所属的年份是否是闰年，私有函数
/// <summary>判断当前日期所属的年份是否是闰年，私有函数</summary>
/// <param name="dt">日期</param>
/// <returns>是闰年：True ，不是闰年：False</returns>
private static bool IsRuYear(DateTime idt)
{
//形式参数为日期类型
//例如：2003-12-12
int n;
n = idt.Year;

if ((n % 400 == 0) || (n % 4 == 0 && n % 100 != 0))
{
return true;
}
else
{
return false;
}
}
#endregion

#region 判断当前年份是否是闰年，私有函数
/// <summary>判断当前年份是否是闰年，私有函数</summary>
/// <param name="dt">年份</param>
/// <returns>是闰年：True ，不是闰年：False</returns>
private static bool IsRuYear(int iYear)
{
//形式参数为年份
//例如：2003
int n;
n = iYear;

if ((n % 400 == 0) || (n % 4 == 0 && n % 100 != 0))
{
return true;
}
else
{
return false;
}
}
#endregion

#region 将输入的字符串转化为日期。如果字符串的格式非法，则返回当前日期
/// <summary>
/// 将输入的字符串转化为日期。如果字符串的格式非法，则返回当前日期。
/// </summary>
/// <param name="strInput">输入字符串</param>
/// <returns>日期对象</returns>
public static DateTime CStrToDate(string strInput)
{
DateTime oDateTime;

try
{
oDateTime = DateTime.Parse(strInput);
}
catch (Exception)
{
oDateTime = DateTime.Today;
}

return oDateTime;
}
#endregion

#region 将日期对象转化为格式字符串
/// <summary>
/// 将日期对象转化为格式字符串
/// </summary>
/// <param name="oDateTime">日期对象</param>
/// <param name="strFormat">日期格式 如yyyy-MM-dd</param>
/// <returns>日期字符串</returns>
public static string CDateToStr(object oDateTime, string strFormat)
{
string strDate = "";
try
{
strDate = Convert.ToDateTime(oDateTime).ToString(strFormat);
}
catch (Exception)
{
strDate = "";
}
return strDate;
}
#endregion

#region 判断是否为合法日期，必须大于1800年1月1日
/// <summary>
/// 判断是否为合法日期，必须大于1800年1月1日
/// </summary>
/// <param name="strDate">输入日期字符串</param>
/// <returns>True/False</returns>
public static bool IsDateTime(string strDate)
{
try
{
DateTime oDate = DateTime.Parse(strDate);
if (oDate.CompareTo(DateTime.Parse("1800-1-1")) > 0)
return true;
else
return false;
}
catch (Exception)
{
return false;
}
}
#endregion

#region 获取两个日期之间的差值 可返回年 月 日 小时 分钟 秒
/// <summary>
/// 获取两个日期之间的差值
/// </summary>
/// <param name="howtocompare">比较的方式可为：year month day hour minute second</param>
/// <param name="startDate">开始日期</param>
/// <param name="endDate">结束日期</param>
/// <returns>时间差</returns>
public static double DateDiff(string howtocompare, DateTime startDate, DateTime endDate)
{
double diff = 0;
try
{
TimeSpan TS = new TimeSpan(endDate.Ticks - startDate.Ticks);

switch (howtocompare.ToLower())
{
case "year":
diff = Convert.ToDouble(TS.TotalDays / 365);
break;
case "month":
diff = Convert.ToDouble((TS.TotalDays / 365) * 12);
break;
case "day":
diff = Convert.ToDouble(TS.TotalDays);
break;
case "hour":
diff = Convert.ToDouble(TS.TotalHours);
break;
case "minute":
diff = Convert.ToDouble(TS.TotalMinutes);
break;
case "second":
diff = Convert.ToDouble(TS.TotalSeconds);
break;
}
}
catch (Exception)
{
diff = 0;
}
return diff;
}
#endregion

#region 计算两个日期之间相差的工作日天数
///  <summary>
///  计算两个日期之间相差的工作日天数
///  </summary>
///  <param  name="dtStart">开始日期</param>
///  <param  name="dtEnd">结束日期</param>
///  <param  name="Flag">是否除去周六，周日</param>
///  <returns>Int</returns>
public static int CalculateWorkingDays(DateTime dtStart, DateTime dtEnd, bool Flag)
{
int count = 0;
for (DateTime dtTemp = dtStart; dtTemp < dtEnd; dtTemp = dtTemp.AddDays(1))
{
if (Flag)
{
if (dtTemp.DayOfWeek != DayOfWeek.Saturday && dtTemp.DayOfWeek != DayOfWeek.Sunday)
{
count++;
}
}
else
{
count++;
}
}
return count;
}
#endregion

#region 格式化时间显示 如yyyy-MM-dd
/// <summary>
/// 格式化时间显示,如错误返回当前时间
/// </summary>
/// <param name="dateObj">待格式化字符串</param>
/// <param name="format">格式 如yyyy-MM-dd</param>
/// <returns></returns>
public static string FormatDateTime(object dateObj, string format)
{
string resultStr = string.Empty;
try
{
resultStr = Convert.ToDateTime(dateObj).ToString(format);
}
catch
{
resultStr = DateTime.Now.ToString(format);
}
return resultStr;
}
#endregion
}
}