- (void)viewDidLoad

{

    [super viewDidLoad];

    // Do any additional setup after loading the view.

    NSString *birthDay=[self birthdayStrFromIdentityCard:@"134825194401014241"];

    NSLog(@"--birthDay-%@",birthDay);

}

//传身份证返回生日字符串

-(NSString *)birthdayStrFromIdentityCard:(NSString *)numberStr{

    NSMutableString *result = [NSMutableString stringWithCapacity:0];

    NSString *year = nil;

    NSString *month = nil;

    BOOL isAllNumber = YES;

    NSString *day = nil;

    if([numberStr length]<14)

        return result;

    //**截取前14位

    NSString *fontNumer = [numberStr substringWithRange:NSMakeRange(0, 13)];

    //**检测前14位否全都是数字;

    const char *str = [fontNumer UTF8String];

    const char *p = str;

    while (*p!='\0') {

        if(!(*p>='0'&&*p<='9'))

            isAllNumber = NO;

        p++;

    }

    if(!isAllNumber)

        return result;

    year = [numberStr substringWithRange:NSMakeRange(6, 4)];

    month = [numberStr substringWithRange:NSMakeRange(10, 2)];

    day = [numberStr substringWithRange:NSMakeRange(12,2)];

    [result appendString:year];

    [result appendString:@"-"];

    [result appendString:month];

    [result appendString:@"-"];

    [result appendString:day];

    return result;

}

2015-10-13 13:26:38.308 传身份证号码可返回生日字符串[6947:172533] --birthDay-1944-01-01