Dart.flutter）#

Jobs倾情奉献

中国公民身份证校验规则

一、Swift的校验方法#

1️⃣ 统一校验规则：格式 → 出生日期 → 顺序码(≠“000”) → 校验位。
2️⃣ 策略
按 GB 11643-1999 的 18 位规则：格式→生日→顺序码→校验位
若输入为 15 位 → 先转换为 18 位（默认世纪补 19），再按 GB 11643-1999 做权重校验。
3️⃣ 默认不做行政区码白名单校验（那份表会变更，容易误杀），但会排除全 0 等明显非法值

import Foundation

enum CNIDError: Error, CustomStringConvertible {
    case format, birthDate, sequence, checksum
    var description: String {
        switch self {
        case .format:    return "格式错误：18位(前17位数字+最后一位数字或X) 或 15位纯数字"
        case .birthDate: return "出生日期无效或超出合理范围"
        case .sequence:  return "顺序码无效（不能为000）"
        case .checksum:  return "校验位不匹配"
        }
    }
}

struct CNID {
    private static let re18 = try! NSRegularExpression(pattern: #"^\d{17}[\dX]$"#)
    private static let re15 = try! NSRegularExpression(pattern: #"^\d{15}$"#)
    private static let weights = [7,9,10,5,8,4,2,1,6,3,7,9,10,5,8,4,2]
    private static let map: [Int: Character] = [0:"1",1:"0",2:"X",3:"9",4:"8",5:"7",6:"6",7:"5",8:"4",9:"3",10:"2"]

    /// 快速校验：自动兼容 15/18 位
    static func isValid(_ raw: String) -> Bool { (try? validate(raw)) != nil }

    /// 严格校验：非法抛错。总是返回“归一化后的18位证号”
    @discardableResult
    static func validate(_ raw: String, centuryHintFor15: Int = 19) throws -> String {
        let s = raw.trimmingCharacters(in: .whitespacesAndNewlines).uppercased()
        if match(re18, s) { try validate18(s); return s }
        if match(re15, s) {
            let v18 = try convert15to18(s, centuryHint: centuryHintFor15)
            try validate18(v18)
            return v18
        }
        throw CNIDError.format
    }

    /// 将 15 位转换为 18 位（默认世纪 “19”）
    static func convert15to18(_ id15: String, centuryHint: Int = 19) throws -> String {
        guard match(re15, id15) else { throw CNIDError.format }
        let area = String(id15.prefix(6))
        let yymmdd = String(id15[id15.index(id15.startIndex, offsetBy:6)..<id15.index(id15.startIndex, offsetBy:12)])
        let seq = String(id15.suffix(3))
        // 15位默认表示 1900-1999 年出生（个别极边缘例外可通过 centuryHint 覆写为 20）
        let yearPrefix = String(centuryHint)
        let yyyyMMdd = yearPrefix + yymmdd
        let body17 = area + yyyyMMdd + seq
        let check = checksumFor(body17)
        return body17 + String(check)
    }

    // MARK: - 私有
    private static func match(_ re: NSRegularExpression, _ s: String) -> Bool {
        re.firstMatch(in: s, range: NSRange(s.startIndex..., in: s)) != nil
    }

    private static func validate18(_ id: String) throws {
        guard match(re18, id) else { throw CNIDError.format }

        // 出生日期
        let y = Int(id[Range(NSRange(location: 6, length: 4), in: id)!])!
        let m = Int(id[Range(NSRange(location:10, length:2), in: id)!])!
        let d = Int(id[Range(NSRange(location:12, length:2), in: id)!])!
        var comps = DateComponents(); comps.year = y; comps.month = m; comps.day = d
        let cal = Calendar(identifier: .gregorian)
        guard let birth = cal.date(from: comps) else { throw CNIDError.birthDate }
        let minDate = cal.date(from: DateComponents(year: 1900, month: 1, day: 1))!
        let maxDate = Date()
        guard (minDate ... maxDate).contains(birth) else { throw CNIDError.birthDate }

        // 顺序码≠"000"
        let seq = id[Range(NSRange(location:14, length:3), in: id)!]
        guard seq != "000" else { throw CNIDError.sequence }

        // 校验位
        let body17 = String(id.prefix(17))
        let expected = checksumFor(body17)
        guard id.last! == expected else { throw CNIDError.checksum }
    }

    private static func checksumFor(_ body17: String) -> Character {
        var sum = 0
        for (i, ch) in body17.enumerated() {
            sum += Int(ch.asciiValue! - Character("0").asciiValue!) * weights[i]
        }
        let r = sum % 11
        return map[r]!
    }
}

let id18 = "510105199307315321"                 // 18位示例（应有效）
let id15 = "130503670401001"                     // 15位经典示例
do {
    let normalizedFrom18 = try CNID.validate(id18)      // 返回18位本身
    let normalizedFrom15 = try CNID.validate(id15)      // 自动转18位
    print("18 -> \(normalizedFrom18)")
    print("15 -> \(normalizedFrom15)")                  // 预期：13050319670401001X
} catch { print("无效：\(error)") }

print("isValid(18):", CNID.isValid(id18))
print("isValid(15):", CNID.isValid(id15))

二、Objc的校验方法#

// CNIDCardValidator.h
#import <Foundation/Foundation.h>

typedef NS_ENUM(NSInteger, CNIDValidationError) {
    CNIDValidationErrorNone = 0,
    CNIDValidationErrorFormat,
    CNIDValidationErrorBirthDate,
    CNIDValidationErrorSequence,
    CNIDValidationErrorChecksum,
};

@interface CNIDCardValidator : NSObject
/// 兼容 15/18 位，仅返回是否有效
+ (BOOL)isValid:(NSString *)idNumber;
/// 兼容 15/18 位，返回“归一化的18位证号”；出错返回 nil，error 填充原因
+ (nullable NSString *)validateAndNormalize:(NSString *)idNumber
                                      error:(CNIDValidationError * _Nullable)errorCode;
/// 仅做 15 -> 18 转换（默认世纪 19）
+ (nullable NSString *)convert15to18:(NSString *)id15 centuryHint:(NSInteger)century;
@end

// CNIDCardValidator.m
#import "CNIDCardValidator.h"

@implementation CNIDCardValidator

+ (BOOL)isValid:(NSString *)idNumber {
    return [self validateAndNormalize:idNumber error:NULL] != nil;
}

+ (NSString *)validateAndNormalize:(NSString *)raw error:(CNIDValidationError *)errorCode {
    CNIDValidationError err = CNIDValidationErrorNone;
    NSString *inStr = [[raw ?: @"" stringByTrimmingCharactersInSet:NSCharacterSet.whitespacesAndNewlineCharacterSet] uppercaseString];

    NSRegularExpression *re18 = [NSRegularExpression regularExpressionWithPattern:@"^\\d{17}[\\dX]$" options:0 error:nil];
    NSRegularExpression *re15 = [NSRegularExpression regularExpressionWithPattern:@"^\\d{15}$" options:0 error:nil];

    BOOL is18 = [re18 numberOfMatchesInString:inStr options:0 range:NSMakeRange(0, inStr.length)] > 0;
    BOOL is15 = !is18 && [re15 numberOfMatchesInString:inStr options:0 range:NSMakeRange(0, inStr.length)] > 0;

    NSString *id18 = nil;
    if (is18) {
        id18 = inStr;
    } else if (is15) {
        id18 = [self convert15to18:inStr centuryHint:19];
        if (!id18) { err = CNIDValidationErrorFormat; goto END; }
    } else { err = CNIDValidationErrorFormat; goto END; }

    // 校验18位
    if (![self validate18:id18 error:&err]) { id18 = nil; }

END:
    if (errorCode) *errorCode = err;
    return id18;
}

+ (NSString *)convert15to18:(NSString *)id15 centuryHint:(NSInteger)century {
    NSRegularExpression *re15 = [NSRegularExpression regularExpressionWithPattern:@"^\\d{15}$" options:0 error:nil];
    if ([re15 numberOfMatchesInString:id15 options:0 range:NSMakeRange(0, id15.length)] == 0) return nil;

    NSString *area = [id15 substringToIndex:6];
    NSString *yymmdd = [id15 substringWithRange:NSMakeRange(6, 6)];
    NSString *seq = [id15 substringFromIndex:12];
    NSString *yyyyMMdd = [NSString stringWithFormat:@"%ld%@", (long)century, yymmdd]; // 默认 19
    NSString *body17 = [NSString stringWithFormat:@"%@%@%@", area, yyyyMMdd, seq];
    unichar check = [self checksumFor:body17];
    return [body17 stringByAppendingFormat:@"%C", check];
}

// ===== 私有 =====
+ (BOOL)validate18:(NSString *)id18 error:(CNIDValidationError *)err {
    // 出生日期
    NSInteger y = [[id18 substringWithRange:NSMakeRange(6, 4)] integerValue];
    NSInteger m = [[id18 substringWithRange:NSMakeRange(10, 2)] integerValue];
    NSInteger d = [[id18 substringWithRange:NSMakeRange(12, 2)] integerValue];

    NSCalendar *cal = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
    NSDateComponents *c = [[NSDateComponents alloc] init];
    c.year = y; c.month = m; c.day = d;
    NSDate *birth = [cal dateFromComponents:c];
    if (!birth) { if (err) *err = CNIDValidationErrorBirthDate; return NO; }

    NSDateComponents *minC = [[NSDateComponents alloc] init];
    minC.year = 1900; minC.month = 1; minC.day = 1;
    NSDate *minDate = [cal dateFromComponents:minC];
    NSDate *maxDate = [NSDate date];
    if ([birth compare:minDate] == NSOrderedAscending || [birth compare:maxDate] == NSOrderedDescending) {
        if (err) *err = CNIDValidationErrorBirthDate; return NO;
    }

    NSString *seq = [id18 substringWithRange:NSMakeRange(14, 3)];
    if ([seq isEqualToString:@"000"]) { if (err) *err = CNIDValidationErrorSequence; return NO; }

    NSString *body17 = [id18 substringToIndex:17];
    unichar expected = [self checksumFor:body17];
    if ([id18 characterAtIndex:17] != expected) { if (err) *err = CNIDValidationErrorChecksum; return NO; }

    if (err) *err = CNIDValidationErrorNone;
    return YES;
}

+ (unichar)checksumFor:(NSString *)body17 {
    static int w[17] = {7,9,10,5,8,4,2,1,6,3,7,9,10,5,8,4,2};
    static char map[11] = {'1','0','X','9','8','7','6','5','4','3','2'};
    long sum = 0;
    for (int i = 0; i < 17; i++) {
        unichar ch = [body17 characterAtIndex:i];
        sum += (ch - '0') * w[i];
    }
    return map[sum % 11];
}

@end

NSString *id18 = @"510105199307315321";
NSString *id15 = @"130503670401001";

CNIDValidationError err;
NSString *norm18 = [CNIDCardValidator validateAndNormalize:id18 error:&err]; // 返回18位
NSString *norm15 = [CNIDCardValidator validateAndNormalize:id15 error:&err]; // 15->18

NSLog(@"18输入→%@", norm18); // 510105199307315321
NSLog(@"15输入→%@", norm15); // 13050319670401001X（经典示例）
NSLog(@"是否有效(18)：%d", [CNIDCardValidator isValid:id18]);
NSLog(@"是否有效(15)：%d", [CNIDCardValidator isValid:id15]);

三、Flutter.dart的校验方法#

// cn_id_card_validator.dart
class CnIdValidationException implements Exception {
  final String message;
  CnIdValidationException(this.message);
  @override
  String toString() => message;
}

class CnID {
  static final RegExp _re18 = RegExp(r'^\d{17}[\dX]$');
  static final RegExp _re15 = RegExp(r'^\d{15}$');
  static const List<int> _w = [7,9,10,5,8,4,2,1,6,3,7,9,10,5,8,4,2];
  static const List<String> _map = ['1','0','X','9','8','7','6','5','4','3','2'];

  /// 仅判断是否有效（自动兼容 15/18）
  static bool isValid(String input) {
    try { normalize(input); return true; } catch (_) { return false; }
  }

  /// 归一化：返回“18位证号”。输入可为 18 或 15 位；15位自动转18（默认世纪 19）
  static String normalize(String raw, {int centuryHintFor15 = 19}) {
    final s = raw.trim().toUpperCase();
    if (_re18.hasMatch(s)) { _validate18(s); return s; }
    if (_re15.hasMatch(s)) {
      final v18 = convert15to18(s, centuryHint: centuryHintFor15);
      _validate18(v18);
      return v18;
    }
    throw CnIdValidationException('格式错误：请输入18位或15位身份证号码');
  }

  /// 仅做 15->18 转换
  static String convert15to18(String id15, {int centuryHint = 19}) {
    if (!_re15.hasMatch(id15)) {
      throw CnIdValidationException('15位格式错误');
    }
    final area = id15.substring(0, 6);
    final yymmdd = id15.substring(6, 12);
    final seq = id15.substring(12, 15);
    final yyyyMMdd = '$centuryHint$yymmdd'; // 默认 19
    final body17 = '$area$yyyyMMdd$seq';
    final check = _checksum(body17);
    return '$body17$check';
  }

  // ===== 私有 =====
  static void _validate18(String id) {
    if (!_re18.hasMatch(id)) {
      throw CnIdValidationException('18位格式错误');
    }
    final y = int.parse(id.substring(6, 10));
    final m = int.parse(id.substring(10, 12));
    final d = int.parse(id.substring(12, 14));
    DateTime birth;
    try {
      birth = DateTime(y, m, d);
      if (birth.year != y || birth.month != m || birth.day != d) {
        throw CnIdValidationException('出生日期无效');
      }
    } catch (_) {
      throw CnIdValidationException('出生日期无效');
    }
    final minDate = DateTime(1900, 1, 1);
    final maxDate = DateTime.now();
    if (birth.isBefore(minDate) || birth.isAfter(maxDate)) {
      throw CnIdValidationException('出生日期超出合理范围');
    }
    if (id.substring(14, 17) == '000') {
      throw CnIdValidationException('顺序码无效（000）');
    }
    final expected = _checksum(id.substring(0, 17));
    final actual = id[17];
    if (actual != expected) {
      throw CnIdValidationException('校验位不匹配：期望 $expected，实际 $actual');
    }
  }

  static String _checksum(String body17) {
    var sum = 0;
    for (var i = 0; i < 17; i++) {
      sum += (body17.codeUnitAt(i) - '0'.codeUnitAt(0)) * _w[i];
    }
    return _map[sum % 11];
  }
}

import 'cn_id_card_validator.dart';

void main() {
  final id18 = '510105199307315321';
  final id15 = '130503670401001';

  // 统一得到 18 位
  try {
    final n18 = CnID.normalize(id18);                // 510105199307315321
    final nFrom15 = CnID.normalize(id15);            // 13050319670401001X
    print('18输入 -> $n18');
    print('15输入 -> $nFrom15');
  } catch (e) {
    print('无效：$e');
  }

  print('isValid(18) = ${CnID.isValid(id18)}');      // true
  print('isValid(15) = ${CnID.isValid(id15)}');      // true
}