iOS判断、过滤和禁用emoji表情

最近项目中碰到的问题，在发送网络请求时，由于用户输入了emoji表情，服务端返回错误提示信息。为了解决服务器不能验证emoji编码的问题，需要在本地进行emoji的输入控制（正常情况下应该由服务器在数据库中添加emoji对应的转码表以支持客户端发送emoji表情），在网上搜了下iOS端解决办法如下：

1.当用户切换键盘为Emoji表情时，输入的表情不响应（即表情符号不显示到UITextView或UITextField）。这里可以通过UITextView或UITextField的回调和是否为emoji键盘：

[[[textView textInputMode] primaryLanguage] isEqualToString:@"emoji"]

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
    
    //不支持系统表情的输入
    if ([[[UITextInputMode currentInputMode ]primaryLanguage] isEqualToString:@"emoji"]) {
        return NO;
    }
    return YES;
}

2.通过过滤用户输入的emoji来实现

//过滤表情
+ (NSString *)filterEmoji:(NSString *)string {
    NSUInteger len = [string lengthOfBytesUsingEncoding:NSUTF8StringEncoding];
    const char *utf8 = [string UTF8String];
    char *newUTF8 = malloc( sizeof(char) * len );
    int j = 0;
   
    //0xF0(4) 0xE2(3) 0xE3(3) 0xC2(2) 0x30---0x39(4)
    for ( int i = 0; i < len; i++ ) {  
        unsigned int c = utf8;
        BOOL isControlChar = NO;
        if ( c == 4294967280 ||
            c == 4294967089 ||
            c == 4294967090 ||
            c == 4294967091 ||
            c == 4294967092 ||
            c == 4294967093 ||
            c == 4294967094 ||
            c == 4294967095 ||
            c == 4294967096 ||
            c == 4294967097 ||
            c == 4294967088 ) {
            i = i + 3;
            isControlChar = YES;
        }
        if ( c == 4294967266 || c == 4294967267 ) {
            i = i + 2;
            isControlChar = YES;
        }
        if ( c == 4294967234 ) {
            i = i + 1;
            isControlChar = YES;
        }
        if ( !isControlChar ) {
            newUTF8[j] = utf8;
            j++;
        }
    }
    newUTF8[j] = '\0';
    NSString *encrypted = [NSString stringWithCString:(const char*)newUTF8
                                             encoding:NSUTF8StringEncoding];
    free( newUTF8 );
    return encrypted;
}

3.通过判断用户输入的字符串时候含有表情来进行对应的操作

//是否含有表情
+ (BOOL)stringContainsEmoji:(NSString *)string
{
    __block BOOL returnValue = NO;
    
    [string enumerateSubstringsInRange:NSMakeRange(0, [string length])
                               options:NSStringEnumerationByComposedCharacterSequences
                            usingBlock:^(NSString *substring, NSRange substringRange, NSRange enclosingRange, BOOL *stop) {
                                const unichar hs = [substring characterAtIndex:0];
                                if (0xd800 <= hs && hs <= 0xdbff) {
                                    if (substring.length > 1) {
                                        const unichar ls = [substring characterAtIndex:1];
                                        const int uc = ((hs - 0xd800) * 0x400) + (ls - 0xdc00) + 0x10000;
                                        if (0x1d000 <= uc && uc <= 0x1f77f) {
                                            returnValue = YES;
                                        }
                                    }
                                } else if (substring.length > 1) {
                                    const unichar ls = [substring characterAtIndex:1];
                                    if (ls == 0x20e3) {
                                        returnValue = YES;
                                    }
                                } else {
                                    if (0x2100 <= hs && hs <= 0x27ff) {
                                        returnValue = YES;
                                    } else if (0x2B05 <= hs && hs <= 0x2b07) {
                                        returnValue = YES;
                                    } else if (0x2934 <= hs && hs <= 0x2935) {
                                        returnValue = YES;
                                    } else if (0x3297 <= hs && hs <= 0x3299) {
                                        returnValue = YES;
                                    } else if (hs == 0xa9 || hs == 0xae || hs == 0x303d || hs == 0x3030 || hs == 0x2b55 || hs == 0x2b1c || hs == 0x2b1b || hs == 0x2b50) {
                                        returnValue = YES;
                                    }
                                }
                            }];
    
    return returnValue;
}

参考地址：http://www.faceye.net/search/90801.html