計算兩個NSDate之間，相隔多少秒數

計算兩個NSDate之間，相隔多少秒數

//兩個時間間隔秒數

- (NSInteger)intervalSecondsWithSmallDate:(NSDate*)smallDate bigDate:(NSDate*)bigDate

{

    NSCalendar *calendar =[NSCalendar currentCalendar];

    

    

    unsigned int unitFlags =kCFCalendarUnitYear|kCFCalendarUnitMonth|kCFCalendarUnitDay|kCFCalendarUnitHour|kCFCalendarUnitMinute|kCFCalendarUnitSecond;

    

    NSDateComponents *dateComp= [calendar components:unitFlags fromDate:smallDate toDate:bigDate options:0];

    NSInteger second = [dateComp hour]*3600+[dateComp minute]*60+[dateComp second];

    

    return second;

    

}