swift4 使用NSCalendar 仿微信/QQ聊天消息时间

前言

因项目需要 界面需要展示时间信息，具体逻辑如下：

根据后台返回时间戳来判断时间是否为今天或昨天，如果不是再判断是否是本周（每周的第一天为周日），如果还不是直接转成年月日。。。

废话不多说，直接上代码：

//日期显示--今天--周几
    class func detailDate24Week(time:Double) -> String{
        let formatter = DateFormatter()
        formatter.dateStyle = DateFormatter.Style.medium
        formatter.timeStyle = DateFormatter.Style.short
        formatter.dateFormat = "YYYY-MM-dd HH:mm:ss"
        let timeInterval = TimeInterval(time/1000.0)
        //获取到date
        let confromTimesp = Date.init(timeIntervalSince1970: timeInterval)
        
        var calender = NSCalendar.current
        // 设置区域
        calender.locale = Locale.init(identifier: "zh_CN")
        // 设置时区
        /*
         设置时区，设置为 GMT+8，即北京时间(+8)
         */
        calender.timeZone = TimeZone.init(abbreviation: "EST")!
        calender.timeZone = TimeZone.init(secondsFromGMT: +28800)!
        // 设定每周的第一天从星期几开始
        /*
         1 代表星期日开始，2 代表星期一开始，以此类推。默认值是 1
         */
        calender.firstWeekday = 1
        
        //ordinalityOfUnit
        let timeWeek = calender.component(.weekOfYear, from: confromTimesp)
        let systimeWeek = calender.component(.weekOfYear, from: Date.init())
        
        if calender.isDateInToday(confromTimesp) {
            
            return "今天"
        }else if calender.isDateInYesterday(confromTimesp) {
            
            return "昨天"
            
        }else if timeWeek == systimeWeek {
            let weeks = ["星期日","星期一","星期二","星期三","星期四","星期五","星期六"]
            let i = calender.ordinality(of: .weekday, in: .weekOfYear, for: confromTimesp)
            //此处一定要记得减1
            return weeks[i!-1]
            
        }else{
            return SwiftFactory.getCurrentTime(timeNum: time, format: "MM-dd")
        }
        
    }

//MARK: - 时间格式转换"YYYY-MM-dd HH:mm:ss"
    class func getCurrentTime(timeNum:Double , format:String) -> String {
        let formatter = DateFormatter()
        formatter.dateStyle = DateFormatter.Style.medium
        formatter.timeStyle = DateFormatter.Style.short
        formatter.dateFormat = format
        let timeInterval = TimeInterval(timeNum/1000.0)
        let confromTimesp = NSDate(timeIntervalSince1970:timeInterval)
        let confromTimespStr = formatter.string(from: confromTimesp as Date)
        return confromTimespStr
    }

新手第一次发帖如有不足请指出。。。