这篇文章上次修改于 306 天前，可能其部分内容已经发生变化，如有疑问可询问作者。

在调用 toStyledString 将 json 对象序列化成字符串时会自动将中文转成 Unicode，比如：\u5e73\u548c\u671b。

解决办法如下：

  1. 在 src\lib_json\json_writer.cpp 中 找到 valueToQuotedStringN 函数，这是将值输出为 json 格式的函数代码

    static JSONCPP_STRING valueToQuotedStringN(const char* value, unsigned length) {
    if (value == NULL)
    return "";

    if (!isAnyCharRequiredQuoting(value, length))
    return JSONCPP_STRING("\"") + value + "\"";
    // We have to walk value and escape any special characters.
    // Appending to JSONCPP_STRING is not efficient, but this should be rare.
    // (Note: forward slashes are *not* rare, but I am not escaping them.)
    JSONCPP_STRING::size_type maxsize = length * 2 + 3; // allescaped+quotes+NULL
    JSONCPP_STRING result;
    result.reserve(maxsize); // to avoid lots of mallocs
    result += "\"";
    char const* end = value + length;
    for (const char* c = value; c != end; ++c) {
    switch (*c) {
    case '\"':
        result += "\\\"";
        break;
    case '\\':
        result += "\\\\";
        break;
    case '\b':
        result += "\\b";
        break;
    case '\f':
        result += "\\f";
        break;
    case '\n':
        result += "\\n";
        break;
    case '\r':
        result += "\\r";
        break;
    case '\t':
        result += "\\t";
        break;
    // case '/':
    // Even though \/ is considered a legal escape in JSON, a bare
    // slash is also legal, so I see no reason to escape it.
    // (I hope I am not misunderstanding something.)
    // blep notes: actually escaping \/ may be useful in javascript to avoid </
    // sequence.
    // Should add a flag to allow this compatibility mode and prevent this
    // sequence from occurring.
    default: {
        unsigned int cp = utf8ToCodepoint(c, end);
        // don't escape non-control characters
        // (short escape sequence are applied above)
        if (cp < 0x80 && cp >= 0x20)
        result += static_cast<char>(cp);
        else if (cp < 0x10000) { // codepoint is in Basic Multilingual Plane
        result += "\\u";
        result += toHex16Bit(cp);
        } else { // codepoint is not in Basic Multilingual Plane
                // convert to surrogate pair first
        cp -= 0x10000;
        result += "\\u";
        result += toHex16Bit((cp >> 10) + 0xD800);
        result += "\\u";
        result += toHex16Bit((cp & 0x3FF) + 0xDC00);
        }
    } break;
    }
    }
    result += "\"";
    return result;
}

  2. 其中，default 就是将中文转为 unicode 格式字符串的代码，可以看到有一段代码是将中文转为 16 进制字符，为了正常输出中文，那么就需要源码这一部分改了，将

    default: {
    unsigned int cp = utf8ToCodepoint(c, end);
    // don't escape non-control characters
    // (short escape sequence are applied above)
    if (cp < 0x80 && cp >= 0x20)
        result += static_cast<char>(cp);
    else if (cp < 0x10000) { // codepoint is in Basic Multilingual Plane
        result += "\\u";
        result += toHex16Bit(cp);
    } else { // codepoint is not in Basic Multilingual Plane
            // convert to surrogate pair first
        cp -= 0x10000;
        result += "\\u";
        result += toHex16Bit((cp >> 10) + 0xD800);
        result += "\\u";
        result += toHex16Bit((cp & 0x3FF) + 0xDC00);
    }
    } break;

    改为：

    default: 
    result += *c;
    break;

    直接将中文字符输出。

  3. 参考资料