创建一个NSPredicate的分类：NSPredicate+HMAdditions

在.h中：

#import <Foundation/Foundation.h>
 
@interface NSPredicate (HMAdditions)
 
+ (BOOL)checkEmail:(NSString *)email;
 
+ (BOOL)checkIDNumber:(NSString *)IDNumber;
 
@end

#import "NSPredicate+HMAdditions.h"
 
@implementation NSPredicate (HMAdditions)
 
+ (BOOL)checkEmail:(NSString *)email
{
    NSString *regex = @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}";
    NSPredicate *predicate = [self predicateWithFormat:@"SELF MATCHES %@",regex];
    return [predicate evaluateWithObject:email];
}
 
+ (BOOL)checkIDNumber:(NSString *)IDNumber
{
    BOOL flag = NO;
    if (IDNumber.length <= 0) {
        return flag;
    }
    NSString *regex = @"^(^[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 *predicate = [self predicateWithFormat:@"SELF MATCHES %@",regex];
    flag = [predicate evaluateWithObject:IDNumber];
    //如果通过该验证，说明身份证格式正确，但准确性还需计算
    if(flag) {
        if(IDNumber.length==18) {
            //将前17位加权因子保存在数组里
            NSArray * idCardWiArray = @[@"7",@"9",@"10",@"5",@"8",@"4",@"2",@"1",@"6",@"3",@"7",@"2"];
            //这是除以11后，可能产生的11位余数、验证码，也保存成数组
            NSArray * idCardYArray = @[@"1",@"0",@"2"];
            //用来保存前17位各自乖以加权因子后的总和
            NSInteger idCardWiSum = 0;
            for(int i = 0;i < 17;i++) {
                NSInteger subStrIndex = [[IDNumber substringWithRange:NSMakeRange(i,1)] integerValue];
                NSInteger idCardWiIndex = [[idCardWiArray objectAtIndex:i] integerValue];
                idCardWiSum+= subStrIndex * idCardWiIndex;
            }
            //计算出校验码所在数组的位置
            NSInteger idCardMod=idCardWiSum%11;
            //得到最后一位身份证号码
            NSString * idCardLast= [IDNumber substringWithRange:NSMakeRange(17,1)];
            //如果等于2，则说明校验码是10，身份证号码最后一位应该是X
            if(idCardMod==2) {
                if([idCardLast isEqualToString:@"X"]||[idCardLast isEqualToString:@"x"]) {
                    return flag;
                }else {
                    flag =  NO;
                    return flag;
                }
            }else {
                //用计算出的验证码与最后一位身份证号码匹配，如果一致，说明通过，否则是无效的身份证号码
                if([idCardLast isEqualToString: [idCardYArray objectAtIndex:idCardMod]]) {
                    return flag;
                } else {
                    flag =  NO;
                    return flag;
                }
            }
        } else {
            flag =  NO;
            return flag;
        }
    } else {
        return flag;
    }
}
 
@end