IOS 时间和时间戳之间转化

以毫秒为整数值的时间戳转换

• 时间戳转化为时间NSDate

- (NSString *)timeWithTimeIntervalString:(NSString *)timeString { // 格式化时间 NSDateFormatter* formatter = [[NSDateFormatter alloc] init]; formatter.timeZone = [NSTimeZone timeZoneWithName:@"shanghai"]; [formatter setDateStyle:NSDateFormatterMediumStyle]; [formatter setTimeStyle:NSDateFormatterShortStyle]; [formatter setDateFormat:@"yyyy年MM月dd日 HH:mm"]; // 毫秒值转化为秒 NSDate* date = [NSDate dateWithTimeIntervalSince1970:[timeString doubleValue]/ 1000.0]; NSString* dateString = [formatter stringFromDate:date]; return dateString; } 

• 时间转化为时间戳

   
     // 当前时间 NSDate* date = [NSDate dateWithTimeIntervalSinceNow:0]; NSTimeInterval a=[date timeIntervalSince1970]*1000; // *1000 是精确到毫秒，不乘就是精确到秒 NSString *timeString = [NSString stringWithFormat:@"%.0f", a]; //转为字符型 

• 通过比较时间与当前时间返回年月日的方法

- (void)getBabyDetailAge:(NSString *)date { // 获得日期对象 NSDateFormatter *formatter_ = [[NSDateFormatter alloc] init]; formatter_.dateFormat = @"yyyy-MM-dd HH:mm:ss"; NSDate *createDate = [formatter_ dateFromString:date]; NSCalendar *gregorian = [[ NSCalendar alloc ] initWithCalendarIdentifier : NSCalendarIdentifierGregorian]; NSUInteger unitFlags = NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear; NSDateComponents *components = [gregorian components:unitFlags fromDate:createDate toDate:[NSDate date] options: 0 ]; NSInteger years = [components year]; NSInteger months = [components month ]; NSInteger days = [components day ]; }