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 DateTimeHelper
  {
    #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 ConvertStringToDate(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">
    /// 格式：
    ///    "SHORTDATE"===短日期
    ///    "LONGDATE"==长日期
    ///    其它====自定义格式
    /// /param>
    /// returns>日期字符串/returns>
    public static string ConvertDateToString(DateTime oDateTime, string strFormat)
    {
      string strDate = "";
      try
      {
        switch (strFormat.ToUpper())
        {
          case "SHORTDATE":
            strDate = oDateTime.ToShortDateString();
            break;
          case "LONGDATE":
            strDate = oDateTime.ToLongDateString();
            break;
          default:
            strDate = oDateTime.ToString(strFormat);
            break;
        }
      }
      catch (Exception)
      {
        strDate = oDateTime.ToShortDateString();
      }
      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
  }
}