身份證校驗

+ (BOOL)stringWithIDCardValidate:(NSString *)idCard{
    
    BOOL flag = YES;
    if (idCard.length <= 0)
    {
        flag = NO;
        return flag;
    }
    
    NSString *regex2 = @"^(^[1-9]\\d{7}((0\\d)|(1[0-2]))(([0|1|2]\\d)|3[0-1])\\d{3}$)|(^[1-9]\\d{5}[1-9]\\d{3}((0\\d)|(1[0-2]))(([0|1|2]\\d)|3[0-1])((\\d{4})|\\d{3}[Xx])$)$";
    NSPredicate *identityCardPredicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",regex2];
    flag = [identityCardPredicate evaluateWithObject:idCard];
    
    
    //若是經過該驗證，說明身份證格式正確，但準確性還需計算
    if(flag)
    {
        if(idCard.length==18)
        {
            //將前17位加權因子保存在數組裏
            NSArray * idCardWiArray = @[@"7", @"9", @"10", @"5", @"8", @"4", @"2", @"1", @"6", @"3", @"7", @"9", @"10", @"5", @"8", @"4", @"2"];
            
            //這是除以11後，可能產生的11位餘數、驗證碼，也保存成數組
            NSArray * idCardYArray = @[@"1", @"0", @"10", @"9", @"8", @"7", @"6", @"5", @"4", @"3", @"2"];
            
            //用來保存前17位各自乖以加權因子後的總和
            
            NSInteger idCardWiSum = 0;
            for(int i = 0;i < 17;i++)
            {
                NSInteger subStrIndex = [[idCard substringWithRange:NSMakeRange(i, 1)] integerValue];
                NSInteger idCardWiIndex = [[idCardWiArray objectAtIndex:i] integerValue];
                
                idCardWiSum+= subStrIndex * idCardWiIndex;
                
            }
            
            //計算出校驗碼所在數組的位置
            NSInteger idCardMod=idCardWiSum%11;
            
            //獲得最後一位身份證號碼
            NSString * idCardLast= [idCard substringWithRange:NSMakeRange(17, 1)];
            
            //若是等於2，則說明校驗碼是10，身份證號碼最後一位應該是X
            if(idCardMod==2)
            {
                if([idCardLast isEqualToString:@"X"]||[idCardLast isEqualToString:@"x"])
                {
                    return flag;
                }else
                {
                    flag =  NO;
                    return flag;
                }
            }else
            {
                //用計算出的驗證碼與最後一位身份證號碼匹配，若是一致，說明經過，不然是無效的身份證號碼
                if([idCardLast isEqualToString: [idCardYArray objectAtIndex:idCardMod]])
                {
                    return flag;
                }
                else
                {
                    flag =  NO;
                    return flag;
                }
            }
        }
        else
        {
            flag =  NO;
            return flag;
        }
    }
    else
    {
        return flag;
    }
}