计算设定时间点与当前时间差的代码

利用时间戳来准确计算某个时间点具现在的时间差，可以参考 CocoaChina 会员 “” 分享的下面这段代码

-
(NSString *)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/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];

}

if (cha/86400>1)

{

timeString = [NSString stringWithFormat:@"%f", cha/86400];

timeString = [timeString substringToIndex:timeString.length-7];

timeString=[NSString stringWithFormat:@"%@天前", timeString];

}

[date release];

return timeString;

}