iOS UITextFiled限制键盘输入及九宫格输入问题

• 最近在做一个注册页面，按需求，要过滤一些特殊字符、Emoje表情 （只允许输入 中文、英文、数字还有空格）来创建用户昵称。

• 发现九宫格输入有个细微的问题: 【输入中文九宫格的预设拼音打不出来】。
  经过一顿查找发现: 中文九宫格输入值为特殊字符。

  
  
  

  九宫格输入值为特殊字符.png

既然找到问题所在了，那么就好解决了，在判断的时候要考虑把九宫格的特殊字符也加进去。

/**
 * 判断 字母、数字、中文
 */
- (BOOL)isInputRuleAndNumber:(NSString *)str
{
    NSString *other = @"➋➌➍➎➏➐➑➒";     //九宫格的输入值
    unsigned long len=str.length;
    for(int i=0;i= 0x4e00 && a <= 0x9fa6))
             ||([other rangeOfString:str].location != NSNotFound)
             ))
            return NO;
    }
    return YES;
}

整个过程如下：

1. 创建TextFiled、设置代理和值改变的监听

  _nickNameTextField = ({
        UITextField *textFiled =[[UITextField alloc]initWithFrame:CGRectMake(self.view.center.x - 240 * 0.5, 200, 240, 22)];
        textFiled.placeholder = @"只允许输入中文、英文、数字";
        //设置输入框的代理
        textFiled.delegate = self;
        //创建输入框的通知
        [textFiled addTarget:self action:@selector(textFieldChanged:) forControlEvents:UIControlEventEditingChanged];
        [self.view addSubview:textFiled];
        textFiled;
    });

2. 在TextFiled代理中进行判断是否满足规则允许输入

#pragma mark ============== TextFieldDelegate ==========
//判断是否满足规则 改变输入框
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
    if ([self isInputRuleAndNumber:string] || [string isEqualToString:@""]) {
        return YES;
    }
    return NO;
}

- (void)textFieldChanged:(UITextField *)textField {
    NSString *toBeString = textField.text;
    NSString *lastString;
    if(toBeString.length>0)
        lastString=[toBeString substringFromIndex:toBeString.length-1];
    
    if (![self isInputRuleAndNumber:toBeString]&&[self hasEmoji:lastString]) {
        textField.text = [self disable_emoji:toBeString];
        return;
    }
    NSString *lang = [[textField textInputMode] primaryLanguage];
    if([lang isEqualToString:@"zh-Hans"]) {
        UITextRange *selectedRange = [textField markedTextRange];
        UITextPosition *position = [textField positionFromPosition:selectedRange.start offset:0];
        if(!position) {
            NSString *getStr = [self getSubString:toBeString];
            if(getStr && getStr.length > 0) {
                textField.text = getStr;
            }
        }
    } else{
        NSString *getStr = [self getSubString:toBeString];
        if(getStr && getStr.length > 0) {
            textField.text= getStr;
        }
    }
}

#pragma mark - privately Method

/**
 * 判断 字母、数字、中文
 */
- (BOOL)isInputRuleAndNumber:(NSString *)str
{
    NSString *other = @"➋➌➍➎➏➐➑➒";     //九宫格的输入值
    unsigned long len=str.length;
    for(int i=0;i= 0x4e00 && a <= 0x9fa6))
             ||([other rangeOfString:str].location != NSNotFound)
             ))
            return NO;
    }
    return YES;
}


/**
 *  获得 kMaxLength长度的字符
 */
-(NSString *)getSubString:(NSString*)string
{
    NSStringEncoding encoding = CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingGB_18030_2000);
    NSData* data = [string dataUsingEncoding:encoding];
    NSInteger length = [data length];
    if (length > kMaxLength) {
        NSData *data1 = [data subdataWithRange:NSMakeRange(0, kMaxLength)];
        NSString *content = [[NSString alloc] initWithData:data1 encoding:encoding];//注意：当截取kMaxLength长度字符时把中文字符截断返回的content会是nil
        if (!content || content.length == 0) {
            data1 = [data subdataWithRange:NSMakeRange(0, kMaxLength - 1)];
            content =  [[NSString alloc] initWithData:data1 encoding:encoding];
        }
        return content;
    }
    return nil;
}

/**
 *  过滤字符串中的emoji
 */
- (BOOL)hasEmoji:(NSString*)str{
    NSString *pattern = @"[^\\u0020-\\u007E\\u00A0-\\u00BE\\u2E80-\\uA4CF\\uF900-\\uFAFF\\uFE30-\\uFE4F\\uFF00-\\uFFEF\\u0080-\\u009F\\u2000-\\u201f\r\n]";
    NSPredicate *pred = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", pattern];
    BOOL isMatch = [pred evaluateWithObject:str];
    return isMatch;
}

- (NSString *)disable_emoji:(NSString *)text{
    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"[^\\u0020-\\u007E\\u00A0-\\u00BE\\u2E80-\\uA4CF\\uF900-\\uFAFF\\uFE30-\\uFE4F\\uFF00-\\uFFEF\\u0080-\\u009F\\u2000-\\u201f\r\n]"options:NSRegularExpressionCaseInsensitive error:nil];
    NSString *modifiedString = [regex stringByReplacingMatchesInString:text
                                                               options:0
                                                                 range:NSMakeRange(0, [text length])
                                                          withTemplate:@""];
    return modifiedString;
}

代码不多，不是很难理解，这次懒得解释，还有一个值得注意的就是 修改 字符最大值,使用了一个宏进行管理。 睡觉去~ 0 0
#define kMaxLength 16

参考链接
http://blog.csdn.net/wodeni512517/article/details/51941606