正则

只允许输入汉字、英文字母（姓名输入框）

NSArray *array = @[@"",@"1",@"e",@"zz11",@"呵呵",@"进口23",@"ee画",@" "];
    for (NSString *str in array) {
        BOOL b = [self isInputRule:str];
        NSLog(@"%@:正则结果%@",str,b?@"YES":@"NO");
    }

控制台输出结果:

2018-11-28 20:16:20.706204+0800 zhengze[1074:37374] :正则结果NO
2018-11-28 20:16:20.706383+0800 zhengze[1074:37374] 1:正则结果NO
2018-11-28 20:16:20.706501+0800 zhengze[1074:37374] e:正则结果YES
2018-11-28 20:16:20.706601+0800 zhengze[1074:37374] zz11:正则结果NO
2018-11-28 20:16:20.706685+0800 zhengze[1074:37374] 呵呵:正则结果YES
2018-11-28 20:16:20.706787+0800 zhengze[1074:37374] 进口23:正则结果NO
2018-11-28 20:16:20.706873+0800 zhengze[1074:37374] ee画:正则结果YES
2018-11-28 20:16:20.706974+0800 zhengze[1074:37374]  :正则结果NO

//只要中文和字母a-zA-Z  ➋➌➍➎➏➐➑➒是9宫格键盘输入时
- (BOOL)isInputRule:(NSString *)str {
    NSString *pattern = @"^[a-zA-Z\u4e00-\u9fa5➋➌➍➎➏➐➑➒]+$";
    NSPredicate *pred = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", pattern];
    BOOL isMatch = [pred evaluateWithObject:str];
    return isMatch;
}

参考：
UITextField只限中文、英文、数字输入和限制字符个数的实现方法
iOS 只能输入英文字母、数字、汉字
iOS-Main-UITextField只允许输入中,英文,数字

只允许输入数字、英文字母（身份证输入框）

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
    if (textField == self.userCardNumTextField){//数字 字母
        NSUInteger lengthOfString = string.length;
        for (NSInteger loopIndex = 0; loopIndex < lengthOfString; loopIndex++) {
            unichar character = [string characterAtIndex:loopIndex];
            //将输入的值转化为ASCII值（即内部索引值），可以参考ASCII表
            // 48-57;{0,9};65-90;{A..Z};97-122:{a..z}
            if (character < 48) return NO; // 48 unichar for 0
            if (character > 57 && character < 65) return NO;
            if (character > 90 && character < 97) return NO;
            if (character > 122) return NO;
        }

        NSUInteger proposedNewLength = textField.text.length - range.length + string.length;
        if (proposedNewLength > 18) {
            return NO;//限制长度
        }
    }

    return YES;
}

可见ASCII码

ASCII表