NSData--NSString转换工具类

//NSDate转NSString

• (NSString *)stringFromDate:(NSDate *)date
  {
  //获取系统当前时间
  NSDate *currentDate = [NSDate date];
  //用于格式化NSDate对象
  NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
  //设置格式：zzz表示时区
  [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss zzz"];
  //NSDate转NSString
  NSString *currentDateString = [dateFormatter stringFromDate:currentDate];
  //输出currentDateString
  NSLog(@"%@",currentDateString);
  return currentDateString;
  }

//NSString转NSDate

• (NSDate *)dateFromString:(NSString *)string
  {
  //需要转换的字符串
  NSString *dateString = @"2015-06-26 08:08:08";
  //设置转换格式
  NSDateFormatter *formatter = [[NSDateFormatter alloc] init] ;
  [formatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
  //NSString转NSDate
  NSDate *date=[formatter dateFromString:dateString];
  return date;
  }