Objective-C身份证验证实现

最近在一个二次开发的项目中看到了一段身份证验证的OC代码，虽然我一直讨厌二次开发。因为这这个二次开发的项目太老，代码太乱，毫无层次感。可是令人欣慰的是，我在里面发现了一段有用的代码。

直接上代码

- (BOOL)isValidIdCardNum
{
    NSString *value = [self copy];
    value = [value stringByReplacingOccurrencesOfString:@"X" withString:@"x"];
    value = [value stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
    int length = 0;
    if (!value) {
        return NO;
    }else {
        length = (int)value.length;
        if (length != 15 && length !=18) {
            return NO;
        }
    }
    // 省份代码
    NSArray *areasArray =@[@"11", @"12", @"13", @"14", @"15", @"21", @"22", @"23", @"31", @"32", @"33", @"34", @"35", @"36", @"37", @"41", @"42", @"43", @"44", @"45", @"46", @"50", @"51", @"52", @"53", @"54", @"61", @"62", @"63", @"64", @"65", @"71", @"81", @"82", @"91"];
    NSString *valueStart2 = [value substringToIndex:2];
    BOOL areaFlag = NO;
    for (NSString *areaCode in areasArray) {
        if ([areaCode isEqualToString:valueStart2]) {
            areaFlag = YES;
            break;
        }
    }
    if (!areaFlag) {
        return NO;
    }
    NSRegularExpression *regularExpression;
    NSUInteger numberofMatch;
    int year = 0;
    switch (length) {
        case 15:
            year = [value substringWithRange:NSMakeRange(6,2)].intValue +1900;
            if (year % 4 ==0 || (year % 100 ==0 && year % 4 ==0)) {
                regularExpression = [[NSRegularExpression alloc] initWithPattern:@"^[1-9][0-9]{5}[0-9]{2}((01|03|05|07|08|10|12)(0[1-9]|[1-2][0-9]|3[0-1])|(04|06|09|11)(0[1-9]|[1-2][0-9]|30)|02(0[1-9]|[1-2][0-9]))[0-9]{3}$"                   options:NSRegularExpressionCaseInsensitive error:nil];// 测试出生日期的合法性
            }else {
                regularExpression = [[NSRegularExpression alloc] initWithPattern:@"^[1-9][0-9]{5}[0-9]{2}((01|03|05|07|08|10|12)(0[1-9]|[1-2][0-9]|3[0-1])|(04|06|09|11)(0[1-9]|[1-2][0-9]|30)|02(0[1-9]|1[0-9]|2[0-8]))[0-9]{3}$"           options:NSRegularExpressionCaseInsensitive error:nil];// 测试出生日期的合法性
            }
            numberofMatch = [regularExpression numberOfMatchesInString:value options:NSMatchingReportProgress range:NSMakeRange(0, value.length)];
            if(numberofMatch > 0) {
                return YES;
            }else {
                return NO;
            }
        case 18:
            year = [value substringWithRange:NSMakeRange(6,4)].intValue;
            if (year % 4 ==0 || (year % 100 ==0 && year % 4 ==0)) {
                regularExpression = [[NSRegularExpression alloc] initWithPattern:@"^[1-9][0-9]{5}19|20[0-9]{2}((01|03|05|07|08|10|12)(0[1-9]|[1-2][0-9]|3[0-1])|(04|06|09|11)(0[1-9]|[1-2][0-9]|30)|02(0[1-9]|[1-2][0-9]))[0-9]{3}[0-9Xx]$"options:NSRegularExpressionCaseInsensitive error:nil];// 测试出生日期的合法性
                
            }else {
                regularExpression = [[NSRegularExpression alloc] initWithPattern:@"^[1-9][0-9]{5}19|20[0-9]{2}((01|03|05|07|08|10|12)(0[1-9]|[1-2][0-9]|3[0-1])|(04|06|09|11)(0[1-9]|[1-2][0-9]|30)|02(0[1-9]|1[0-9]|2[0-8]))[0-9]{3}[0-9Xx]$"
                                                                         options:NSRegularExpressionCaseInsensitive error:nil];// 测试出生日期的合法性
            }
            numberofMatch = [regularExpression numberOfMatchesInString:value options:NSMatchingReportProgress range:NSMakeRange(0, value.length)];
            if(numberofMatch > 0) {
                int S = ([value substringWithRange:NSMakeRange(0,1)].intValue + [value substringWithRange:NSMakeRange(10,1)].intValue) *7 + ([value substringWithRange:NSMakeRange(1,1)].intValue + [value substringWithRange:NSMakeRange(11,1)].intValue) *9 + ([value substringWithRange:NSMakeRange(2,1)].intValue + [value substringWithRange:NSMakeRange(12,1)].intValue) *10 + ([value substringWithRange:NSMakeRange(3,1)].intValue + [value substringWithRange:NSMakeRange(13,1)].intValue) *5 + ([value substringWithRange:NSMakeRange(4,1)].intValue + [value substringWithRange:NSMakeRange(14,1)].intValue) *8 + ([value substringWithRange:NSMakeRange(5,1)].intValue + [value substringWithRange:NSMakeRange(15,1)].intValue) *4 + ([value substringWithRange:NSMakeRange(6,1)].intValue + [value substringWithRange:NSMakeRange(16,1)].intValue) *2 + [value substringWithRange:NSMakeRange(7,1)].intValue *1 + [value substringWithRange:NSMakeRange(8,1)].intValue *6 + [value substringWithRange:NSMakeRange(9,1)].intValue *3;
                int Y = S % 11;
                NSString *M = @"F";
                NSString *JYM = @"10X98765432";
                M = [JYM substringWithRange:NSMakeRange(Y,1)]; // 判断校验位
                if ([M isEqualToString:[[value substringWithRange:NSMakeRange(17,1)] uppercaseString]]) {
                    return YES;// 检测ID的校验位
                }else {
                    return NO;
                }
            }else {
                return NO;
            }
            
        default:
            return NO;
    }
    return NO;
}

上面的代码验证十分全面。