iOS objective-c 取当前时间计算年龄时间差
实例一：iOS 获取当前时间以及计算年龄
获取当前时间
NSDate *now = [NSDate date];
NSLog(@”now date is: %@”, now);
NSCalendar *calendar = [NSCalendar currentCalendar];
NSUInteger unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit;
NSDateComponents *dateComponent = [calendar components:unitFlags fromDate:now];
int year = [dateComponent year];
int month = [dateComponent month];
int day = [dateComponent day];
int hour = [dateComponent hour];
int minute = [dateComponent minute];
int second = [dateComponent second];
NSLog(@”year is: %d”, year);
NSLog(@”month is: %d”, month);
NSLog(@”day is: %d”, day);
NSLog(@”hour is: %d”, hour);
NSLog(@”minute is: %d”, minute);
NSLog(@”second is: %d”, second);
计算年龄
第一种只得出年份差的年龄
//计算年龄
NSString *birth = @"1993-10-30";
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init];
[dateFormatter setDateFormat:@"yyyy-MM-dd"];
//生日
NSDate *birthDay = [dateFormatter dateFromString:birth];
//当前时间
NSString *currentDateStr = [dateFormatter stringFromDate:[NSDate date]];
NSDate *currentDate = [dateFormatter dateFromString:currentDateStr];
NSLog(@"currentDate %@ birthDay %@",currentDateStr,birth);
NSTimeInterval time=[currentDate timeIntervalSinceDate:birthDay];
int age = ((int)time)/(3600*24*365);
NSLog(@"year %d",age);
第二种得出具体到天的年龄
NSCalendar *calendar = [NSCalendar currentCalendar];//定义一个NSCalendar对象
NSDate *nowDate = [NSDate date];
NSString *birth = @"1900-10-30";
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init];
[dateFormatter setDateFormat:@"yyyy-MM-dd"];
//生日
NSDate *birthDay = [dateFormatter dateFromString:birth];
//用来得到具体的时差
unsigned int unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit;
NSDateComponents *date = [calendar components:unitFlags fromDate:birthDay toDate:nowDate options:0];
if([date year] >0)
{
NSLog(@"%@",[NSString stringWithFormat:(@"%ld岁%ld月%ld天"),(long)[date year],(long)[date month],(long)[date day]]) ;
}
else if([date month] >0)
{
NSLog(@"%@",[NSString stringWithFormat:(@"%ld月%ld天"),(long)[date month],(long)[date day]]);
}
else if([date day]>0){
NSLog(@"%@",[NSString stringWithFormat:(@"%ld天"),(long)[date day]]);
}
else {
NSLog(@"0天");
}
字符串、日期、Int转换
1、字符串转换为日期
NSDateFormatter* dateFormat = [[NSDateFormatter alloc] init];//实例化一个NSDateFormatter对象
[dateFormat setDateFormat:@"yyyy-MM-dd HH:mm:ss"];//设定时间格式,这里可以设置成自己需要的格式
NSDate *date =[dateFormat dateFromString:@"1980-01-01 00:00:01"];
2、日期转换为字符串
NSDateFormatter* dateFormat = [[NSDateFormatter alloc] init];//实例化一个NSDateFormatter对象
[dateFormat setDateFormat:@"yyyy-MM-dd HH:mm:ss"];//设定时间格式,这里可以设置成自己需要的格式
NSString *currentDateStr = [dateFormat stringFromDate:[NSDate date]];
3、字符串转int
Convert NSString to int
NSString *aNumberString = @"123";
int i = [aNumberString intValue];
4、int转字符串
Convert int to NSString
int aNumber = 123;
NSString *aString = [NSString stringWithFormat:@"%d", aNumber];
实例二：iOS 计算某个时间点与现在的时间差
/*处理返回应该显示的时间*/
+ (NSString *) returnUploadTime:(NSDictionary *)dic
{
//Tue May 21 10:56:45 +0800 2013
NSString *timeStr = [dic objectForKey:@"created_at"];
NSDateFormatter *date=[[NSDateFormatter alloc] init];
[date setDateFormat:@"E MMM d HH:mm:SS Z y"];
NSDate *d=[date dateFromString:timeStr];
NSTimeInterval late=[d timeIntervalSince1970]*1;
NSDate* dat = [NSDate dateWithTimeIntervalSinceNow:0];
NSTimeInterval now=[dat timeIntervalSince1970]*1;
NSString *timeString=@"";
NSTimeInterval cha=now-late;
if (cha/3600<1) {
timeString = [NSString stringWithFormat:@"%f", cha/60];
timeString = [timeString substringToIndex:timeString.length-7];
timeString=[NSString stringWithFormat:@"%@分钟前", timeString];
}
if (cha/3600>1&&cha/86400<1) {
// timeString = [NSString stringWithFormat:@"%f", cha/3600];
// timeString = [timeString substringToIndex:timeString.length-7];
// timeString=[NSString stringWithFormat:@"%@小时前", timeString];
NSDateFormatter *dateformatter=[[NSDateFormatter alloc] init];
[dateformatter setDateFormat:@"HH:mm"];
timeString = [NSString stringWithFormat:@"今天 %@",[dateformatter stringFromDate:d]];
[dateformatter release];
}
if (cha/86400>1)
{
// timeString = [NSString stringWithFormat:@"%f", cha/86400];
// timeString = [timeString substringToIndex:timeString.length-7];
// timeString=[NSString stringWithFormat:@"%@天前", timeString];
NSDateFormatter *dateformatter=[[NSDateFormatter alloc] init];
[dateformatter setDateFormat:@"YY-MM-dd HH:mm"];
timeString = [NSString stringWithFormat:@"%@",[dateformatter stringFromDate:d]];
[dateformatter release];
}
[date release];
return timeString;
}
实例三：IOS 计算当前时间与某时间的时间差
- (int)intervalSinceNow: (NSString *) theDate
{
NSDateFormatter *date=[[NSDateFormatter alloc] init];
[date setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
NSDate *d=[date dateFromString:theDate];
NSTimeInterval late=[d timeIntervalSince1970]*1;
NSDate* dat = [NSDate dateWithTimeIntervalSinceNow:0];
NSTimeInterval now=[dat timeIntervalSince1970]*1;
NSString *timeString=@"";
NSTimeInterval cha=now-late;
if (cha/86400>1)
{
timeString = [NSString stringWithFormat:@"%f", cha/86400];
timeString = [timeString substringToIndex:timeString.length-7];
return [timeString intValue];
}
return -1;
}
上面的例子只是计算相差了几天
当然可以计算其他数值
cha/3600<1 分钟
if (cha/3600>1&&cha/86400<1) 小时
// 获取当前日期
NSDate *date = [NSDate date];
// 打印结果： 当前时间 date = 2013-08-16 09:00:04 +0000
NSLog(@"当前时间 date = %@",date);
// 获取从某个日期开始往前或者往后多久的日期，此处60代表60秒，如果需要获取之前的，将60改为-60即可
date = [[NSDate alloc] initWithTimeInterval:60 sinceDate:[NSDate date]];
//打印结果：当前时间 往后60s的时间date = 2013-08-16 09:01:04 +0000
NSLog(@"当前时间 往后60s的时间date = %@",date);
PS：测试时时间是下午5点，但是得到的当前时间却是上午9点，相差了8小时，是时区的问题
解决办法：
NSTimeZone *zone = [NSTimeZone systemTimeZone];
NSInteger interval = [zone secondsFromGMTForDate: date];
NSDate *localDate = [date dateByAddingTimeInterval: interval];
// 打印结果 正确当前时间 localDate = 2013-08-16 17:01:04 +0000
NSLog(@"正确当前时间 localDate = %@",localDate);
