jsoncpp 1.8.4 中文值乱码问题指南

最近在使用c++解析 读写 json文件发现jsoncpp接口写出来的中文值都是 \u6e21\uxxxx等，字符；传入的std::string 已经是utf-8编码了；按理来说不应该乱码才对；

代码是在gitbub上下载编译的1.8.4；

 

using namespace std;

#include "json\include\json.h"
#include "json\include\writer.h"
#include 
#include 
#include 
#include 
#include 
#include "ANSI_UTF8_UNICODE_Translate.h"

using namespace utf_ansi_unicode_translate;
int main()
{
    int nRetCode = 0;

    HMODULE hModule = ::GetModuleHandle(nullptr);

    if (hModule != nullptr)
    {
        // 初始化 MFC 并在失败时显示错误
        if (!AfxWinInit(hModule, nullptr, ::GetCommandLine(), 0))
        {
            // TODO: 更改错误代码以符合您的需要
            wprintf(L"错误: MFC 初始化失败\n");
            nRetCode = 1;
        }
        else
        {
            // TODO: 在此处为应用程序的行为编写代码。

			Json::StreamWriterBuilder writer0;
			Json::Value root;
			Json::Value useproperty;
			{
				useproperty["title"] = "Tips";
				useproperty["type"] = "string";
				std::string str_ansi = "温馨提示";
				useproperty["value_ansi"] = str_ansi;
				std::string str_utf8 = AnsiToUtf8(str_ansi);
				useproperty["value_utf8"] = str_utf8;
				std::wstring str_uincode = UTF8ToUnicode(str_utf8);
				str_utf8 = UnicodeToUTF8(str_uincode);
				useproperty["value_unicode"] = str_utf8;
				root["Userproperty"] = useproperty;
			}
			root["tmp"] = "/mnt/share/a3/0527";
			root["type"] = "DLG";

			Json::StreamWriterBuilder builder;
			builder["commentStyle"] = "None";
			builder["indentation"] = "   ";  // or whatever you like
			builder["emitUTF8"] = true;

			std::string str = Json::writeString(builder, root);
			std::unique_ptr writer(builder.newStreamWriter());
			writer->write(root, &std::cout);
			std::cout << std::endl;  // add lf and flush
			std::ofstream ofs;
			ofs.open("F:\\Code\\0525\\json_test\\bin\\my_json002.json", 0x02);
			ASSERT(ofs.is_open());
			writer->write(root, &ofs);
			ofs.close(); 
			int a;
			std::cin >> a;
        }
    }
    else
    {
        // TODO: 更改错误代码以符合您的需要
        wprintf(L"错误: GetModuleHandle 失败\n");
        nRetCode = 1;
    }

    return nRetCode;
}

#pragma once
#include 
using namespace std;
namespace utf_ansi_unicode_translate
{
	std::wstring StdstrToStdwstr(const std::string& strAnsi);

	std::wstring AnsiToUnicode(const std::string& strAnsi);
	std::string UnicodeToANSI(const std::wstring& strUnicode);
	std::wstring UTF8ToUnicode(const std::string& str);
	std::string UnicodeToUTF8(const std::wstring& strUnicode);
	std::string AnsiToUtf8(const std::string& strAnsi);
	std::string Utf8ToAnsi(const std::string& strUtf8);
	//探测输入字符串是否是UTF8字符串
	bool IsUtf8String(const char* pString);
};

#include "stdafx.h"
#include "ANSI_UTF8_UNICODE_Translate.h"
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include "stdafx.h"

namespace utf_ansi_unicode_translate
{
	std::wstring StdstrToStdwstr(const std::string& strAnsi)
	{
		if (IsUtf8String(strAnsi.c_str()))
			return UTF8ToUnicode(strAnsi);
		else
			return AnsiToUnicode(strAnsi);
	}

	std::wstring AnsiToUnicode(const std::string& strAnsi)
	{
		//获取转换所需的接收缓冲区大小
		int  nUnicodeLen = ::MultiByteToWideChar(CP_ACP,
			0,
			strAnsi.c_str(),
			-1,
			NULL,
			0);
		//分配指定大小的内存
		wchar_t* pUnicode = new wchar_t[nUnicodeLen + 1];
		memset((void*)pUnicode, 0, (nUnicodeLen + 1) * sizeof(wchar_t));

		//转换
		::MultiByteToWideChar(CP_ACP,
			0,
			strAnsi.c_str(),
			-1,
			(LPWSTR)pUnicode,
			nUnicodeLen);

		std::wstring  strUnicode;
		strUnicode = (wchar_t*)pUnicode;
		delete[]pUnicode;

		return strUnicode;
	}
	std::string UnicodeToANSI(const std::wstring& strUnicode)
	{
		int nAnsiLen = WideCharToMultiByte(CP_ACP,
			0,
			strUnicode.c_str(),
			-1,
			NULL,
			0,
			NULL,
			NULL);

		char* pAnsi = new char[nAnsiLen + 1];
		memset((void*)pAnsi, 0, (nAnsiLen + 1) * sizeof(char));

		::WideCharToMultiByte(CP_ACP,
			0,
			strUnicode.c_str(),
			-1,
			pAnsi,
			nAnsiLen,
			NULL,
			NULL);

		std::string strAnsi;
		strAnsi = pAnsi;
		delete[]pAnsi;

		return strAnsi;
	}
	std::wstring UTF8ToUnicode(const std::string& str)
	{
		int nUnicodeLen = ::MultiByteToWideChar(CP_UTF8,
			0,
			str.c_str(),
			-1,
			NULL,
			0);

		wchar_t* pUnicode;
		pUnicode = new wchar_t[nUnicodeLen + 1];
		memset((void*)pUnicode, 0, (nUnicodeLen + 1) * sizeof(wchar_t));

		::MultiByteToWideChar(CP_UTF8,
			0,
			str.c_str(),
			-1,
			(LPWSTR)pUnicode,
			nUnicodeLen);

		std::wstring  strUnicode;
		strUnicode = (wchar_t*)pUnicode;
		delete[]pUnicode;

		return strUnicode;
	}
	std::string UnicodeToUTF8(const std::wstring& strUnicode)
	{
		int nUtf8Length = WideCharToMultiByte(CP_UTF8,
			0,
			strUnicode.c_str(),
			-1,
			NULL,
			0,
			NULL,
			NULL);

		char* pUtf8 = new char[nUtf8Length + 1];
		memset((void*)pUtf8, 0, sizeof(char) * (nUtf8Length + 1));

		::WideCharToMultiByte(CP_UTF8,
			0,
			strUnicode.c_str(),
			-1,
			pUtf8,
			nUtf8Length,
			NULL,
			NULL);

		std::string strUtf8;
		strUtf8 = pUtf8;
		delete[] pUtf8;

		return strUtf8;
	}

	std::string AnsiToUtf8(const std::string& strAnsi)
	{
		//先判断一下是不是utf-8 字符；若是 则直接返回；
		if (IsUtf8String(strAnsi.c_str()))
		{
			return strAnsi;
		}
		std::wstring strUnicode = AnsiToUnicode(strAnsi);
		return UnicodeToUTF8(strUnicode);
	}

	std::string Utf8ToAnsi(const std::string& strUtf8)
	{
		//先判断一下是不是utf-8 字符；若不是 则直接返回；
		if (!IsUtf8String(strUtf8.c_str()))
		{
			return strUtf8;
		}

		std::wstring strUnicode = UTF8ToUnicode(strUtf8);
		return UnicodeToANSI(strUnicode);
	}

	/*
	UTF-8 编码规则
	1字节 0BBBBBBB
	2字节 110BBBBB 10BBBBBB
	3字节 1110BBBB 10BBBBBB 10BBBBBB
	4字节 11110BBB 10BBBBBB 10BBBBBB 10BBBBBB
	5字节 111110BB 10BBBBBB 10BBBBBB 10BBBBBB 10BBBBBB
	6字节 1111110B 10BBBBBB 10BBBBBB 10BBBBBB 10BBBBBB 10BBBBBB
	*/
	bool IsUtf8String(const char* pString)
	{
		bool bRet = true;

		//输入长度
		int iStrLen = pString ? strlen(pString) : 0;
		//临时变量
		int m = 0, n = 0, iBLen = 0;  BYTE b0 = 0;
		for (m = 0; bRet && m < iStrLen; )
		{
			//根据第一个字节计算长度
			b0 = (BYTE)pString[m];
			iBLen = 0;
			if ((b0 & 0x80) == 0x00) { iBLen = 1; } //1字节
			else if ((b0 & 0xE0) == 0xC0) { iBLen = 2; } //2字节
			else if ((b0 & 0xF0) == 0xE0) { iBLen = 3; } //3字节
			else if ((b0 & 0xF8) == 0xF0) { iBLen = 4; } //4字节
			else if ((b0 & 0xFC) == 0xF8) { iBLen = 5; } //5字节
			else if ((b0 & 0xFE) == 0xFC) { iBLen = 6; } //6字节
			else {} //非法

					//非法长度或超出缓冲区范围
			if (iBLen <= 0 || m + iBLen > iStrLen)
			{
				bRet = false;
				break;
			}

			//判断后续字节需 10xxxxxx
			for (n = 1; n < iBLen; n++)
			{
				if ((pString[m + n] & 0xC0) == 0x80)
					continue;

				bRet = false;
				break;
			}
			//对齐到下一个长度
			m += iBLen;
		}
		return bRet;
	}


};

结果如图：发现中文是乱码的；

 

后面调试发现是 static JSONCPP_STRING valueToQuotedStringN(const char* value, unsigned length) {} 这里是转换将中文code转成了乱码；

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 = 0x20)
          result += static_cast(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);
        }
*/
//此处为新增代码
		result += *c;
		std::cout << result;
      }
      break;
    }
  }
  result += "\"";
  std::cout << result;
  return result;
}

修改jsoncpp源码后；测试结果正确：