由於專案中需要校驗使用者輸入的身份證是否滿18歲，且網上的方法魚龍混雜，故自定義校驗方法如下：

• 第一種方法：

 //驗證身份證是否成年這個方法中不做身份證校驗，請確保傳入的是正確身份證
 + (BOOL)verifyIDCardWithAdult:(NSString *)card{

//身份證：****年**月**日
     //年
     NSString *year = [card substringWithRange:NSMakeRange(6,4)];
     NSInteger  birthdayYear = [year integerValue];
     //月
     NSString
 
 *month = [card substringWithRange:NSMakeRange(10,2)];
     NSInteger  birthdayMonth = [month integerValue];
     //日
     NSString *day = [card substringWithRange:NSMakeRange(12,2)];
     NSInteger  birthdayDay = [day integerValue];


//獲取當前時間，日期：
     NSDate *currentDate = [NSDate date];
     NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
     [dateFormatter setDateFormat:@"YYYY/MM/dd"
 
];
     NSString *dateString = [dateFormatter stringFromDate:currentDate];
     NSRange range0 = [dateString rangeOfString:@"/"];
     //年
     NSString *year0 = [dateString substringToIndex:range0.location];
     NSInteger  nowYear = [year0 integerValue];
     //月
     NSString *month0 = [dateString substringWithRange:NSMakeRange(5
 
, 2)];
     NSInteger  nowMonth = [month0 integerValue];
     //日
     NSString *day0 = [dateString substringWithRange:NSMakeRange(8, 2)];
     NSInteger  nowDay = [day0 integerValue];


//具體校驗：
     //年
     if (nowYear - birthdayYear < 18){

         return false;
     }else if (nowYear - birthdayYear == 18){

         //月
         if (nowMonth < birthdayMonth){

             return false;


         }else if (nowMonth == birthdayMonth){

             //日
            if (nowDay < birthdayDay){

                return false;
            }
         }
     }
     return true;
}

• 第二種方法：

+ (BOOL)verifyIDCardHadAdultII:(NSString *)card{

    //身份證：****年**月**日
    //年
    NSString *year = [card substringWithRange:NSMakeRange(6,4)];
    int  birthdayYear = [year intValue];
    birthdayYear+=18;

    //月日
    NSString *monthDay = [card substringWithRange:NSMakeRange(10,4)];
    int  birthdayMonth = [monthDay intValue];
    NSString *birthdayDay = [NSString stringWithFormat:@"%d%d",birthdayYear,birthdayMonth];

    //獲取當前時間，日期：
    NSDate *currentDate = [NSDate date];
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:@"YYYYMMdd"];
    NSString *dateString = [dateFormatter stringFromDate:currentDate];

    //年
    NSString *year0 = [dateString substringWithRange:NSMakeRange(0, 4)];
    int  nowYear = [year0 intValue];
    //月日
    NSString *month0 = [dateString substringWithRange:NSMakeRange(4, 4)];
    int  nowMonth = [month0 intValue];
    NSString *current = [NSString stringWithFormat:@"%d%d",nowYear,nowMonth];


    //比較
    if([birthdayDay compare:current options:NSNumericSearch] == NSOrderedDescending){

        return false;
    }

    return true;
}