从 NSDate 获取历史时间（例如 5s ago 2 分钟前 3 小时前）

这可以在各种聊天应用程序，RSS 订阅源和社交应用程序中使用，你需要使用时间戳记的最新订阅源：

Objective-C

- (NSString *)getHistoricTimeText:(NSDate *)since
{
    NSString *str;
    NSTimeInterval interval = [[NSDate date] timeIntervalSinceDate:since];
    if(interval < 60)
        str = [NSString stringWithFormat:@"%is ago",(int)interval];
    else if(interval < 3600)
    {
        int minutes = interval/60;
        str = [NSString stringWithFormat:@"%im ago",minutes];
    }
    else if(interval < 86400)
    {
        int hours =  interval/3600;
        
        str = [NSString stringWithFormat:@"%ih ago",hours];
    }
    else
    {
        NSDateFormatter *dateFormater=[[NSDateFormatter alloc]init];
        [dateFormater setLocale:[NSLocale currentLocale]];
        NSString *dateFormat = [NSDateFormatter dateFormatFromTemplate:@"MMM d, YYYY" options:0 locale:[NSLocale currentLocale]];
        [dateFormater setDateFormat:dateFormat];
        str = [dateFormater stringFromDate:since];
        
    }
    return str;
}