iOS emoji表情显示, 过滤emoji表情

// iOS中的表情符号是emoji表情，需要将表情符号进行转换，后台才能识别。识别方法：

NSString * str1 = [str stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]; (iOS 9后被另一个方法替换
NSString * str1 =  [str stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet characterSetWithCharactersInString:@"`#%^{}\"[]|\\<> "].invertedSet];
)

// 我们给后台上传的是Hahh%F0%9F%98%85这样的字符串，同样发回给我们的也是Hahh%F0%9F%98%85。
// 那么问题来了，我们要怎样识别这些表情字符，并将表情显示出来？这时就需要我们使用另一个方法，将表情符号识别并显示出来了

 NSString * str2 = [str1  stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
    NSLog(@"%@", str2);（iOS9之后被另一个方法替换：
NSString * str2 = [str1 stringByRemovingPercentEncoding];

//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;
}

 

转载于:https://my.oschina.net/iOScoderZhao/blog/796292