iOS 计算两个时间差

将某个时间戳转化成 时间

 NSString *res = [self timestampSwitchTime:[timestamp integerValue] andFormatter:@"YYYY-MM-dd hh:mm:ss"];
#pragma mark - 将某个时间戳转化成 时间
+ (NSString *)timestampSwitchTime:(NSInteger)timestamp andFormatter:(NSString *)format{
    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    [formatter setDateStyle:NSDateFormatterMediumStyle];
    [formatter setTimeStyle:NSDateFormatterShortStyle];
    [formatter setDateFormat:format]; // （@"YYYY-MM-dd hh:mm:ss"）----------设置你想要的格式,hh与HH的区别:分别表示12小时制,24小时制
    NSTimeZone *timeZone = [NSTimeZone timeZoneWithName:@"Asia/Beijing"];
    [formatter setTimeZone:timeZone];
    NSDate *confromTimesp = [NSDate dateWithTimeIntervalSince1970:timestamp];
    /// 在当前时间，后退30分钟 = 1800
//    confromTimesp = [confromTimesp dateByAddingTimeInterval:-1800];
    NSLog(@"1296035591 = %@",confromTimesp);
    NSString *confromTimespStr = [formatter stringFromDate:confromTimesp];
    return confromTimespStr;
}

计算两个时间点差值

NSInteger vipLastTime = [self pleaseInsertStarTimeo:res andInsertEndTime:[PublicDatas session].userInfo.expireTime];
+ (NSInteger)pleaseInsertStarTimeo:(NSString *)time1 andInsertEndTime:(NSString *)time2{
    // 1.将时间转换为date
    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    formatter.dateFormat = @"YYYY-MM-dd hh:mm:ss";
    NSDate *date1 = [formatter dateFromString:time1];
    NSDate *date2 = [formatter dateFromString:time2];
    // 2.创建日历
    NSCalendar *calendar = [NSCalendar currentCalendar];
//    NSCalendarUnit type = NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay | NSCalendarUnitHour | NSCalendarUnitMinute | NSCalendarUnitSecond;
    NSCalendarUnit type = NSCalendarUnitSecond;
    // 3.利用日历对象比较两个时间的差值
    NSDateComponents *cmps = [calendar components:type fromDate:date1 toDate:date2 options:0];
    // 4.输出结果
    NSLog(@"两个时间相差%ld年%ld月%ld日%ld小时%ld分钟%ld秒", cmps.year, cmps.month, cmps.day, cmps.hour, cmps.minute, cmps.second);
    return cmps.second;
}