swift - 错误 - 实例成员不能用于类型自定义类

Question

我正在尝试获取今天的日期

import Foundation

class Date {
  var calendar = NSCalendar.currentCalendar()
  var day = calendar.component(NSCalendarUnit.Day, fromDate: NSDate())
}

但我总是报错

Instance member 'calendar' cannot be used on type 'Date'

Answer 1

您不能在实例化时访问日历属性:

像这样尝试:

class Date {
    let calendar = NSCalendar.currentCalendar()
    var day: Int {
       return  calendar.component(.Day, fromDate: NSDate())
    }
}


print(Date().day)   // 17