将形如:Oct 8, 2016 5:29:44 PM串转换成正常时间在真机上遇到的坑

/**

 *  根据传入字符串

 *

 *  @param str 传入的日期字符串  形如:Oct 8, 2016 5:29:44 PM

 *

 *  @return 返回所需要的日期字符串  形如:10-08 06:26:55

 */

+ (NSString *)getStrFromDate:(NSString *)str {

    NSDateFormatter *formatter = [[NSDateFormatter alloc]init];

    [formatter setDateStyle:NSDateFormatterMediumStyle];

    [formatter setTimeStyle:NSDateFormatterShortStyle];

    [formatter setDateFormat:@"MMM d,yyyy HH:mm:ss aa"];

    //设置时区 这个对时间的处理有时很重要

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

    [formatter setTimeZone:timeZone];

    NSLocale *local = [[NSLocale alloc] initWithLocaleIdentifier:@"en_US"];

    [formatter setLocale:local];

    NSDate *date = [formatter dateFromString:str];  //2016-10-08 10:26:55 +0000

    NSDateFormatter *dateFormatter=[[NSDateFormatter alloc]init];//创建一个日期格式化器

    [dateFormatter setDateStyle:NSDateFormatterMediumStyle];

    [dateFormatter setTimeStyle:NSDateFormatterShortStyle];

    dateFormatter.dateFormat=@"yyyy-MM-dd hh:mm:ss";//指定转date得日期格式化形式

    NSString *str1 = [dateFormatter stringFromDate:date];

    JGLog(@"转换后： %@",str1);

    return [str1 substringWithRange:NSMakeRange(0, 11)];

}