日期格式化

 日期格式化

  NSDateFormatter *formatter = [[NSDateFormatteralloc]init];

  [formatter setDateFormat:@"YYYY-MM-dd hh:mm:ss"];

 NSTimeZone *timeZone = [NSTimeZonetimeZoneWithName:@"Asia/Shanghai"];

  [formattersetTimeZone:timeZone];

 NSString *currentDate = [formatterstringFromDate:[NSDatedate]];

 [formatterrelease];

或

NSDateFormatter *formatter = [[NSDateFormatteralloc]init];

  [formatter setDateFormat:@"YYYY-MM-dd HH:mm:ss"];

 NSString *currentDate = [formatterstringFromDate:[NSDatedate]];

 [formatterrelease];

 //这里要注意的是formatter的格式，如果是小写的"hh",那么时间将会跟着系统设置变成12小时或者24小时制。大写的HH，则强制为24小时制