使用Swift进行NSDate比较

我喜欢使用扩展使代码更具可读性。以下是一些NSDate扩展，它们可以帮助清理代码并使其易于理解。我把它放在一个sharedCode.swift文件中：

extension NSDate {    func isGreaterThanDate(dateToCompare: NSDate) -> Bool {        //Declare Variables        var isGreater = false        //Compare Values        if self.compare(dateToCompare as Date) == ComparisonResult.orderedDescending { isGreater = true        }        //Return Result        return isGreater    }    func isLessThanDate(dateToCompare: NSDate) -> Bool {        //Declare Variables        var isLess = false        //Compare Values        if self.compare(dateToCompare as Date) == ComparisonResult.orderedAscending { isLess = true        }        //Return Result        return isLess    }    func equalToDate(dateToCompare: NSDate) -> Bool {        //Declare Variables        var isEqualTo = false        //Compare Values        if self.compare(dateToCompare as Date) == ComparisonResult.orderedSame { isEqualTo = true        }        //Return Result        return isEqualTo    }    func addDays(daysToAdd: Int) -> NSDate {        let secondsInDays: TimeInterval = Double(daysToAdd) * 60 * 60 * 24        let dateWithDaysAdded: NSDate = self.addingTimeInterval(secondsInDays)        //Return Result        return dateWithDaysAdded    }    func addHours(hoursToAdd: Int) -> NSDate {        let secondsInHours: TimeInterval = Double(hoursToAdd) * 60 * 60        let dateWithHoursAdded: NSDate = self.addingTimeInterval(secondsInHours)        //Return Result        return dateWithHoursAdded    }}

现在，如果您可以执行以下操作：

//Get Current Date/Timevar currentDateTime = NSDate()//Get Reminder Date (which is Due date minus 7 days lets say)var reminderDate = dueDate.addDays(-7)//Check if reminderDate is Greater than Right nowif(reminderDate.isGreaterThanDate(currentDateTime)) {    //Do Something...}