• (NSString *)compareCurrentTime:(NSString *)str
  {

  //把字符串轉為NSdate
  NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
  [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
  NSDate *timeDate = [dateFormatter dateFromString:str];
  //八小時時區
  NSTimeZone *zone = [NSTimeZone systemTimeZone];
  NSInteger interval = [zone secondsFromGMTForDate: timeDate];
  NSDate *mydate = [timeDate dateByAddingTimeInterval: interval];
  NSDate *nowDate =[[NSDate date] dateByAddingTimeInterval: interval];
  // 兩個時間間隔
  NSTimeInterval timeInterval= [mydate timeIntervalSinceDate:nowDate];
  timeInterval = -timeInterval;

  NSLog(@"時間是%f",timeInterval);

  long temp = 0;
  NSString *result;
  if (timeInterval < 60) {
  result = [NSString stringWithFormat:@"剛剛"];
  }
  else if((temp = timeInterval/60) <60){
  result = [NSString stringWithFormat:@"%ld分鐘前",temp];
  }

  else if((temp = timeInterval/(60*60)) <24){
  result = [NSString stringWithFormat:@"%ld小時前",temp];
  }

  else if((temp = timeInterval/(246060)) <30){
  result = [NSString stringWithFormat:@"%ld天前",temp];
  }

  else if((temp = timeInterval/(24606030)) <12){
  result = [NSString stringWithFormat:@"%ld月前",temp];
  }
  else{
  temp = timeInterval/(24606030*12);
  result = [NSString stringWithFormat:@"%ld年前",temp];
  }

  return result;
  }

時間相乘 ，顯示錯誤?－ － ！