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一、把含有表情的字符串编码 ---- UTF-8

- (NSString *)emojiEncode{     NSString *uniStr = [NSString stringWithUTF8String:[self UTF8String]];    NSData *uniData = [uniStr dataUsingEncoding:NSNonLossyASCIIStringEncoding];    NSString *emojiText = [[NSString alloc] initWithData:uniData encoding:NSUTF8StringEncoding];    return emojiText;}

二、把请求到的含有表情字符串数据解码，解码后直接在UILabel上显示 ---- UTF-8

- (NSString *)emojiDecode{    const char *jsonString = [self UTF8String];    NSData *jsonData = [NSData dataWithBytes:jsonString length:strlen(jsonString)];    NSString *emojiText = [[NSString alloc] initWithData:jsonData encoding:NSNonLossyASCIIStringEncoding];    return emojiText;}

注意：这样做微信端不能显示表情，也不能显示微信端上传的表情。

三、使用网页形式的表情格式(&#数字;)显示表情

//遍历含有表情的字符串，把表情替换成HTML格式的

//把UITextView或者UItextField里面text直接拿出来进行表情格式化 //把格式化之后的数据上传服务器

-(NSString *)replaceEmoji:(NSString *)text{    //过滤表情正则表达式    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];    // 对text字符串进行匹配    NSArray *matches = [regex matchesInString:text                                    options:0                                      range:NSMakeRange(0, text.length)];    // 遍历匹配后的每一条记录    NSString *result = text;    for (NSTextCheckingResult *match in matches) {        NSRange range = [match range];        NSString *target = [text substringWithRange:range];        NSLog(@"%@", target);        //把表情转换成HTML格式的        NSString *emojiS = [target emojiUnicodeToHTML];        //替换回原来的位置        result = [result stringByReplacingOccurrencesOfString:target withString:emojiS];    }    return result;}

//把表情转成网页能显示型的HTML格式(&#数字;)微信直接显示

#define MULITTHREEBYTEUTF16TOUNICODE(x,y) (((((x ^ 0xD800) << 2) | ((y ^ 0xDC00) >> 8)) << 8) | ((y ^ 0xDC00) & 0xFF)) + 0x10000- (NSString *)emojiUnicodeToHTML{    NSString *hexstr = @"";    if ([self length] >= 2) {            for (int i = 0; i < [self length] / 2 && ([self length] % 2 == 0) ; i++)                {            // three bytes            if (([self characterAtIndex:i*2] & 0xFF00) == 0 ) {                hexstr = [hexstr stringByAppendingFormat:@"Ox%1X 0x%1X",[self characterAtIndex:i*2],[self characterAtIndex:i*2+1]];            }            else            {// four bytes                hexstr = [hexstr stringByAppendingFormat:@"%1X ",MULITTHREEBYTEUTF16TOUNICODE([self characterAtIndex:i*2],[self characterAtIndex:i*2+1])];            }                }        NSLog(@"(unicode) [%@]",hexstr);    }    else        {        NSLog(@"(unicode) U+%1X",[self characterAtIndex:0]);    }    NSString *html = [NSString stringWithFormat:@"%lu",strtoul([hexstr UTF8String],0,16)];    return [NSString stringWithFormat:@"&#%@;",html];}

//解析网页形式的表情格式在UILabel上显示

//把微信端表情转成Unicode编码（如果能支持unicode 字符串 那么直接获取U+1F604 输出即可，如果不支持，那么获取png图片显示即可，下面的convertSimpleUnicodeStr方法获取） //把微信端的HTML形式的表情转换成iOS端显示用的Unicode格式

匹配HTML格式表情正则.png

- (NSString *)digitalEmojiToUnicode:(NSString *)string{    //把微信端上传的表情处理成iOS字符串    NSString *text = [string htmlToString];    //匹配HTML格式表情正则    NSString *prefix = @"[^&#]*\\;";    NSRegularExpression *regular = [NSRegularExpression regularExpressionWithPattern:prefix                                                                         options:NSRegularExpressionCaseInsensitive                                                                           error:nil];    // 对text字符串进行匹配    NSArray *matches = [regular matchesInString:text                                    options:0                                      range:NSMakeRange(0, text.length)];    // 遍历匹配后的每一条记录    NSString *result =  text；    for (NSTextCheckingResult *match in matches) {        NSRange range = [match range];        NSString *target = [text substringWithRange:range];        NSLog(@"%@", target);        //把HTML格式的表情转换为Unicode格式的        NSString *emojiS = [target emojiHTMLToUnicode];        //iOS 端直接支持unicode字符 (有一些高级表情会失败，返回nil)        NSString *convertUnicode = [emojiS convertSimpleUnicodeStr];        if (convertUnicode.length ==0) {            convertUnicode = @"❓";（高级表情显示不出来）        }        //把表情替换回原来的位置，然后就能直接用UILabel显示表情了        result = [result stringByReplacingOccurrencesOfString:[@"&#" stringByAppendingString:target] withString:convertUnicode];        }    return result;}

注意：上面代码里面的正则表达式不对，符号被简书改了，看图片。

- (NSString *)emojiHTMLToUnicode{    NSString *result = [self stringByReplacingOccurrencesOfString:@"&#" withString:@""];    result = [result stringByReplacingOccurrencesOfString:@";" withString:@""];    NSString *hexString = [NSString stringWithFormat:@"U+%@",[[NSString alloc] initWithFormat:@"%1X",[result intValue]]];    return hexString;}

//这段函数作用是将 U+1F591 转换为 \U0001F591

//如果为 U+2500 那么就是补全为 \U00002500 //返回的sendStr就是可以直接在UILabel上显示的表情

- (NSString *)convertSimpleUnicodeStr{    NSString *strUrl = [self stringByReplacingOccurrencesOfString:@"U+" withString:@""];    unsigned long  unicodeIntValue= strtoul([strUrl UTF8String],0,16);    //   UTF32Char inputChar = unicodeIntValue ;// 变成utf32    unsigned long inputChar = unicodeIntValue ;// 变成utf32    //    inputChar = NSSwapHostIntToLittle(inputChar); // 转换成Little 如果需要inputChar = NSSwapHostLongToLittle(inputChar); // 转换成Little 如果需要NSString *sendStr = [[NSString alloc] initWithBytes:&inputChar length:4 encoding:NSUTF32LittleEndianStringEncoding];NSLog(@"%@",sendStr);return sendStr;

}

//网页内容转String

- (NSString *)htmlToString{    NSData *data = [self dataUsingEncoding:NSUTF8StringEncoding];    if (data.length > 0) {        return  [[NSAttributedString alloc] initWithData:data options:@{NSDocumentTypeDocumentAttribute:NSHTMLTextDocumentType,NSCharacterEncodingDocumentAttribute:[NSNumber numberWithInteger:NSUTF8StringEncoding]} documentAttributes:nil error:nil].string;    }    return @"";}

注意：这个方法是把网页格式的数据变成字符串

慢慢来，一步一个巴掌印。。。。。

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