计算两个NSDate之间，相隔多少秒数

计算两个NSDate之间，相隔多少秒数

//两个时间间隔秒数

- (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;

    

}