更完美的《iOS中textField、textView判断过滤禁用emoji表情》，解决过滤表情后九宫格输入不了问题

上一篇中对textField和textView等输入过滤的判断，后来我发现并不好，使用于苹果没有推出新表情。但是后来又发现，当输入法切换成九宫格时输入不了。然后查了下资料，发现了一个更好的方法，给大家分享下：

1、UITextField添加监听方法（UITextView不用此监听）

[textField addTarget:self action:@selector(textFieldDidChange:) forControlEvents:UIControlEventEditingChanged];

2、输入时处理（ UITextView中string替换成text，textField替换成textView ，监听方法用- (void)textViewDidChangeSelection:(UITextView *)textView代替）

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString*)string{
    
    if ([self isInputRuleAndNumber:string] || [string isEqualToString:@""]){
        return YES;
    }else{
        return NO;
    }
    
}
//textField输入的监听方法：过滤表情等 和 限制输入字数
- (void)textFieldDidChange:(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;
    }
    
    
    //限制输入字数,如果没有该功能的下面的代码可以不要！
    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;
        }
    }
    
}

3、特殊文字处理、输入文本长度限制、过滤emoji表情

/**
 * 字母、数字、中文
 */
- (BOOL)isInputRuleAndNumber:(NSString *)str
{
    NSString *other = @"➋➌➍➎➏➐➑➒";
    unsigned long len=str.length;
    for(int i=0;i    {
        unichar a=[str characterAtIndex:i];
        if(!((isalpha(a))
             ||(isalnum(a))
             ||((a=='_') || (a == '-'))
             ||((a >= 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];
    //kMaxLength:文本输入数字限制
    if (length > kMaxLength) {
        NSData *data1 = [data subdataWithRange:NSMakeRange(0, kMaxLength)];
        NSString *cOntent= [[NSString alloc] initWithData:data1 encoding:encoding];//【注意4】：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;
}

＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊

更新于：2016年11月9日

注：上面的方法会把输入法中的标点符号也过滤点！

有朋友私信我说怎么输入时打不了标点符号，标点符号也给过滤了。这里我再补充下怎么去掉过滤标点符号的出路：

1、下面的代理方法去掉

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text{

    if ([self isInputRuleAndNumber:text] || [text isEqualToString:@""]){
        return YES;
    }else{
        return NO;
    }

}

2、输入的监听方法里 - (void)textViewDidChangeSelection:(UITextView *)textView; 稍微修改下

//输入的监听方法里 - (void)textViewDidChangeSelection:(UITextView *)textView;
if (![self isInputRuleAndNumber:toBeString]&&[self hasEmoji:lastString]) {
    textView.text = [self disable_emoji:toBeString];
    return;
}
//改成下面就可以了
if ([self hasEmoji:lastString]) {
    textView.text = [self disable_emoji:toBeString];
    return;
}

通过上面的两步操作便可以实现标点符号的输入。

如果有什么问题大家可以私信我，大家一块学习！