转自：http://www.cnblogs.com/yuan-chong/p/HolidayHelper.html
一、开发背景：
最近在公司开发的系统中，需要计算工作日，就是给出一个采购周期（n天），我需要计算出在n个工作日之后的日期。开始准备去调接口（ps:找了半天发现没有太合适的，还有吐槽下国家*单位都没有官方接口的），但是负责这个项目的大佬说，万一别个的接口崩了，会影响我们自己的系统的正常运行，自己开发还是稳点，我就写了这个功能，特此记录下实现这个功能的思路。
二、定义：
工作日想必大家都知道，就是除去周末和每年国务院颁布的节假日放假安排(例如：2017年部分节假日安排)，其他就都是工作日(对了，差点忘记补班，这也算是工作日哦)。
三、实践：
“废话”说的够多了，下面撸起袖子开干吧，代码都写了注释。
提供了两个公共方法，先给大家看下简单测试的运行结果：
(1).根据传入的工作日天数，获得计算后的日期
(2).根据传入的时间，计算工作日天数；
具体代码：
public class HolidayHelper
{
#region 字段属性
private static object _syncObj = new object();
private static HolidayHelper _instance { get; set; }
private static List<DateModel> cacheDateList { get; set; }
private HolidayHelper() { }
/// <summary>
/// 获得单例对象,使用懒汉式（双重锁定）
/// </summary>
/// <returns></returns>
public static HolidayHelper GetInstance()
{
if (_instance == null)
{
lock (_syncObj)
{
if (_instance == null)
{
_instance = new HolidayHelper();
}
}
}
return _instance;
}
#endregion
#region 私有方法
/// <summary>
/// 读取文件
/// </summary>
/// <param name="filePath"></param>
/// <returns></returns>
private string GetFileContent(string filePath)
{
string result = "";
if (File.Exists(filePath))
{
result = File.ReadAllText(filePath);
}
return result;
}
/// <summary>
/// 获取配置的Json文件
/// </summary>
/// <returns>经过反序列化之后的对象集合</returns>
private List<DateModel> GetConfigList()
{
string path = string.Format("{0}/../../Config/holidayConfig.json", System.AppDomain.CurrentDomain.BaseDirectory);
string fileContent = GetFileContent(path);
if (!string.IsNullOrWhiteSpace(fileContent))
{
cacheDateList = Newtonsoft.Json.JsonConvert.DeserializeObject<List<DateModel>>(fileContent);
}
return cacheDateList;
}
/// <summary>
/// 获取指定年份的数据
/// </summary>
/// <param name="year"></param>
/// <returns></returns>
private DateModel GetConfigDataByYear(int year)
{
if (cacheDateList == null)//取配置数据
GetConfigList();
DateModel result = cacheDateList.FirstOrDefault(m => m.Year == year);
return result;
}
/// <summary>
/// 判断是否为工作日
/// </summary>
/// <param name="currDate">要判断的时间</param>
/// <param name="thisYearData">当前的数据</param>
/// <returns></returns>
private bool IsWorkDay(DateTime currDate, DateModel thisYearData)
{
if (currDate.Year != thisYearData.Year)//跨年重新读取数据
{
thisYearData = GetConfigDataByYear(currDate.Year);
}
if (thisYearData.Year > 0)
{
string date = currDate.ToString("MMdd");
int week = (int)currDate.DayOfWeek;
if (thisYearData.Work.IndexOf(date) >= 0)
{
return true;
}
if (thisYearData.Holiday.IndexOf(date) >= 0)
{
return false;
}
if (week != 0 && week != 6)
{
return true;
}
}
return false;
}
#endregion
#region 公共方法
public void CleraCacheData()
{
if (cacheDateList != null)
{
cacheDateList.Clear();
}
}
/// <summary>
/// 根据传入的工作日天数，获得计算后的日期,可传负数
/// </summary>
/// <param name="day">天数</param>
/// <param name="isContainToday">当天是否算工作日（默认：true）</param>
/// <returns></returns>
public DateTime GetReckonDate(int day, bool isContainToday = true)
{
DateTime currDate = DateTime.Now;
int addDay = day >= 0 ? 1 : -1;
if (isContainToday)
currDate = currDate.AddDays(-addDay);
DateModel thisYearData = GetConfigDataByYear(currDate.Year);
if (thisYearData.Year > 0)
{
int sumDay = Math.Abs(day);
int workDayNum = 0;
while (workDayNum < sumDay)
{
currDate = currDate.AddDays(addDay);
if (IsWorkDay(currDate, thisYearData))
workDayNum++;
}
}
return currDate;
}
/// <summary>
/// 根据传入的时间，计算工作日天数
/// </summary>
/// <param name="date">带计算的时间</param>
/// <param name="isContainToday">当天是否算工作日（默认：true）</param>
/// <returns></returns>
public int GetWorkDayNum(DateTime date, bool isContainToday = true)
{
var currDate = DateTime.Now;
int workDayNum = 0;
int addDay = date.Date > currDate.Date ? 1 : -1;
if (isContainToday)
{
currDate = currDate.AddDays(-addDay);
}
DateModel thisYearData = GetConfigDataByYear(currDate.Year);
if (thisYearData.Year > 0)
{
bool isEnd = false;
do
{
currDate = currDate.AddDays(addDay);
if (IsWorkDay(currDate, thisYearData))
workDayNum += addDay;
isEnd = addDay > 0 ? (date.Date > currDate.Date) : (date.Date < currDate.Date);
} while (isEnd);
}
return workDayNum;
}
#endregion
}
public struct DateModel
{
public int Year { get; set; }
public List<string> Work { get; set; }
public List<string> Holiday { get; set; }
}
说明下，法定节假日我是自己用json来配置的，大家可以自己维护，或者做成自己的接口。下面展示下json的格式，这是我自己配置的(2015-2017年)，大家可以按照自己的需求来修改。
[
{
"Year": "2015",
"Work": [ "0104", "0215", "0228", "0906", "1010" ],
"Holiday": [ "0101", "0102", "0103", "0218", "0219", "0220", "0221", "0222", "0223", "0224", "0404", "0405", "0406", "0501", "0502", "0503", "0620", "0621", "0622", "0903", "0904", "0905", "0927", "1001", "1002", "1003", "1004", "1005", "1006", "1007" ]
},
{
"Year": "2016",
"Work": [ "0206", "0214", "0612", "0918", "1008", "1009" ],
"Holiday": [ "0101", "0207", "0208", "0209", "0210", "0211", "0212", "0213", "0404", "0501", "0502", "0609", "0610", "0611", "0915", "0916", "0917", "1001", "1002", "1003", "1004", "1005", "1006", "1007" ]
},
{
"Year": "2017",
"Work": [ "0122", "0204", "0401", "0527", "0930" ],
"Holiday": [ "0101", "0102", "0127", "0128", "0129", "0130", "0201", "0202", "0501", "0529", "0530", "1001", "1002", "1003", "1004", "1005", "1006" ]
}
]
holidayConfig.json