swift之日历NSCalender、日期Date

 

参考：https://www.jianshu.com/p/2d3195f9556e

/**
 时间Date、日历calender
 */
import UIKit

class LYBCalenderAndDateExtention: NSObject {
    
   
}


extension String{
    // 获取当前系统时间，转换成字符串
  static  func dateTodateStr(date:Date)->(String){
        let timeFormatter = DateFormatter()
//        let timeZone = TimeZone.init(identifier: "UTC")//时区,不加上这个时区设置就是世界标准协调时间，比中国现在的时间少8小时
//        timeFormatter.timeZone = timeZone
        timeFormatter.locale = Locale.init(identifier: "zh_CN")//本地化设置
        timeFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss.SSS"//年月日时分秒毫秒
        let nowTimestr = timeFormatter.string(from: date as Date) as String
      return nowTimestr
    }
    
    //时间字符串转换成date
    static   func dateStrToDate(dateStr:String)->(Date){
      
        let timeFormatter = DateFormatter()
        let timeZone = TimeZone.init(identifier: "UTC")//时区
        timeFormatter.timeZone = timeZone//不设置时区，就会少8小时
        timeFormatter.locale = Locale.init(identifier: "zh_CN")//本地化设置
        timeFormatter.dateFormat = "yyyyMMddHHmmss"
        
        return timeFormatter.date(from: dateStr)!
    }
    
    //比较两个日期字符串相差几天
//    调用：String.compareDate(oneDateStr:oneDateStr:String,twoDateStr:String,twoDateStr:"2016-12-24")
    static   func compareDate(oneDateStr:String,twoDateStr:String)->Int{
        let firstDate = oneDateStr
        let secondDate = twoDateStr
        let cformatter = DateFormatter()
        cformatter.dateFormat = "yyyy-MM-dd"
        let sDate = cformatter.date(from: firstDate)
        let cDate = cformatter.date(from: secondDate)
        let intervals = cDate?.timeIntervalSince(sDate!)//时间差(单位是秒)
        let day_seconds = 24*3600 //一天的秒数
        let days = Int(intervals!)/day_seconds //结果就是两个日期的时间差(单位是天)
        return days
    }
    
    
    
    //MARK: 日历的基本知识
    static   fileprivate func calendarBasic(){
        
        var calendar = Calendar.current
        calendar.locale = Locale.init(identifier: "zh_CN")
        print(calendar.timeZone)
        print(Date.init())
        
        //Date.init()是默认的值，是格林威治的标准时间，如果需要本地话，可以用formatter格式一下即可
        
        /*
         let timeFormatter = DateFormatter()
         timeFormatter.dateFormat = "yyy-MM-dd HH:mm:ss.S Z" //(格式可按自己需求修整)
         let strNowTime = timeFormatter.string(from: Date.init()) as String
         print(strNowTime)
         */
        
        /*历标示符
         identifier 的范围可以是:
         NSCalendarIdentifierGregorian         公历
         NSCalendarIdentifierBuddhist          佛教日历
         NSCalendarIdentifierChinese           中国农历
         NSCalendarIdentifierHebrew            希伯来日历
         NSCalendarIdentifierIslamic           伊斯兰日历
         NSCalendarIdentifierIslamicCivil      伊斯兰教日历
         NSCalendarIdentifierJapanese          日本日历
         NSCalendarIdentifierRepublicOfChina   中华民国日历（台湾）
         NSCalendarIdentifierPersian           波斯历
         NSCalendarIdentifierIndian            印度日历
         NSCalendarIdentifierISO8601           ISO8601
         */
        // 获取地区信息标示符
        let calendarIdentifier = calendar.identifier
        print(calendarIdentifier)//gregorian代表公历
        
        // 获取地区信息
        let calendarLocalIdentifier = calendar.locale?.identifier
        print(calendarLocalIdentifier ?? "calendarLocalIdentifier is nil")
        
        // 获取时区信息
        let calendarTimeZone = calendar.timeZone
        print(calendarTimeZone)
        
        //获取每周的第一天从星期几开始
        let firstWeekDay = calendar.firstWeekday
        print(firstWeekDay)//1代表sunday，周日
        
        // 获取第一周必须包含的最少天数
        let minDaysInFirstWeek = calendar.minimumDaysInFirstWeek
        print(minDaysInFirstWeek)
    }
   
    
    /**
    自定义日历转化为date
     */
    static  func calenderToDate(){
        //1, 可以手动创建components，然后进行自定义赋值，还可以将components转换成date对象
        var components = DateComponents.init()
        components.day = 35
        components.month = 5
        components.year = 2004
        components.weekday = 4
        components.hour = 30
        
        let weekday = components.weekday
        print(weekday ?? "weekday is nil")
        
        //这里默认的是0时区
        let gregorian = Calendar.init(identifier: .gregorian)//公历日历
        let customDate = gregorian.date(from: components)
        print(customDate ?? "customeDate is nil")
        //只需要用DateFormatter格式化一下就可以成为我们当前的8时区
        let formatter = DateFormatter.init()
        formatter.dateFormat = "yyyy年MM月dd日 HH时mm分ss秒 Z"
        let theDate = formatter.string(from: customDate!)
        print(theDate)
        
      
    }
    
    /**
     date转化为日历
     */
    static   func dateToCalender(){
        //2, 也可将日期转化成dateComponents
        let nowTime = Date.init()
        let calendar = Calendar.current
        let component = calendar.component(.second, from: nowTime)
        print(component)
        let componentsSet = Set<Calendar.Component>([.year, .month, .day, .hour, .minute, .second])
        let componentss = calendar.dateComponents(componentsSet, from: nowTime)
        print(componentss)
      
  
    }
    
    /**
       农历和阳历切换
     */
 
    fileprivate func calendarSwitch(){
        let date = Date.init()
        let dateFormatter = DateFormatter.init()
        dateFormatter.dateFormat = "yyyy年MM月dd日 HH时mm分ss秒 Z"
        let formatedDate = dateFormatter.string(from: date)
        print(formatedDate)
        
        //切换到中国农历（如果之前有创建其他日历，需要先把之前到日历给释放或者清空）
        let chinese = Calendar.init(identifier: .chinese)
        let components = Set<Calendar.Component>([.year, .month, .day, .hour, .minute, .second])
        let theComponents = chinese.dateComponents(components, from: date)
        print("阴历的日期是：\(theComponents)")
    }
    
    /**
     日期当前日期加上一些时间
     */

    static func addCertainTime()->String{
        let todayTime = Date.init()
        let calendar = Calendar.current
        
        var offSetComponents = DateComponents.init()
        offSetComponents.hour = 2
        
        let adjustTime = calendar.date(byAdding: offSetComponents, to: todayTime)
        
        let dateFormatter = DateFormatter.init()
        dateFormatter.dateFormat = "yyyy年MM月dd日 HH时mm分ss秒 Z"
        
        let theAdjustTime = dateFormatter.string(from: adjustTime!)
        
      return theAdjustTime
        
    }
   
    /**
     获取当前周中的星期几
     */
    
    fileprivate func getSundayFromCurrentWeek(){
        
        let todayTime = Date.init()
        let calendar = Calendar.current
        let weekDayComponents = calendar.dateComponents(Set<Calendar.Component>([.weekday]), from: todayTime)
        var componentsToSubtract = DateComponents.init()
        componentsToSubtract.day = 0 - (weekDayComponents.weekday! - 1)
        let beginningOfWeek = calendar.date(byAdding: componentsToSubtract, to: todayTime)
        let dateFormatter = DateFormatter.init()
        dateFormatter.dateFormat = "yyyy年MM月dd日 HH时mm分ss秒 Z"
        let theBeginningOfWeek = dateFormatter.string(from: beginningOfWeek!)
        
        print(theBeginningOfWeek)
    }
  
    /**
     计算出一周中的第一天,或周末第一天，或一月中第一天，一年中第一天等
     */
   
    fileprivate func getFirstDayFromWeek(){
        let dateFormatter = DateFormatter.init()
        dateFormatter.dateFormat = "yyyy年MM月dd日 HH时mm分ss秒 Z"
        
        let dateStr = "2017年05月08日 10时03分25秒 +0800"
        let date = dateFormatter.date(from: dateStr)
        
        let calendar = Calendar.current
        
        /*得到该日期的开始时间，也就是凌晨零点
         let date = calendar.startOfDay(for: todayDate)
         print(date)
         */
        
        /*获取周末开始时间
         var beginningOfWeekend: Date = Date.init()
         var interval: TimeInterval = 0
         let ok = calendar.dateIntervalOfWeekend(containing: date!, start: &beginningOfWeekend, interval: &interval)
         if ok == true{
         let theBeginningOfWeekend = dateFormatter.string(from: beginningOfWeekend)
         print("本周日开始日期是：\(theBeginningOfWeekend)")
         }else{
         print("给值不是周末")
         }*/
        
        //获取本周的第一天
        var beginningOfWeek: Date = Date.init()
        var interval01:TimeInterval = 0
        let ok01 = calendar.dateInterval(of: .weekOfMonth, start: &beginningOfWeek, interval: &interval01, for: date!)
        
        if ok01 == true{
            let thebeginningOfWeek = dateFormatter.string(from: beginningOfWeek)
            print(thebeginningOfWeek)
        }else{
            print("失败")
        }
    }
    
    /**
       获取两个日期之间的间隔,通过日历计算
     */
   
    fileprivate func calcTheIntervalBetweenTwoDate(){
        let dateFormatter = DateFormatter.init()
        dateFormatter.dateFormat = "yyyy年MM月dd日 HH时mm分ss秒 Z"
        
        //第一个日期设置成当前日期好了
        let firDate = Date.init()
        
        //第二个日期随手设置一个
        let secDateStr = "2017年04月05日 10时03分25秒 +0800"
        let secDate = dateFormatter.date(from: secDateStr)
        
        let calendar = Calendar.current
        let timeInterval = calendar.dateComponents(Set<Calendar.Component>([.year, .month, .day, .hour, .minute, .second]), from: firDate, to: secDate!)
        
        print(timeInterval)
    }
    
    /**
     获取日历中的年月日时分每秒
    调用：  print("\(String(describing: weekDayComponents.day))")//获取天
     */
  
    func getCalenderYMDhms()->DateComponents{
        let now = Date.init()
        let calendar = Calendar.current
         let weekDayComponents = calendar.dateComponents(Set<Calendar.Component>([.year, .month, .day, .hour, .minute, .second]), from: now)
        return weekDayComponents
      
    }
}