摘要：
//得到当前的日期NSDate *date = [NSDate date];NSLog(@"date:%@",date);//得到(24 * 60 * 60)即24小时之前的日期，dateWithTimeIntervalSinceNow:NSDate *yesterday = [NSDate dateWithTimeIntervalSinceNow: -(24 * 60 * 60)];NSLog(@"yesterday:%@",yesterday);NSDateFormatter *formatter =[[[NSDateFormatter alloc] 阅读全文
