c++ - C++ 字符串类型更改和拆分代码结果不好

Question

我想将 LPCWSTR 转换为 std::string，然后拆分它，然后再次将其转换为 LPCWSTR。但是这个函数打印？？？？？？？？？如何解决？

string convLPCWSTRtostring(const LPCWSTR a) {
            long size = wcslen(a);
                char* cString = new char[size];
                for (long i = 0; i < size-1; i++)
                {
                        cString[i] = a[i];
                }
                string String(cString);
                return(String);
        }
    


LPCWSTR convstringtoLPCWSTR(const string s) {
    
        wstring my_str;
        my_str.assign(s.begin(), s.end());
        LPCWSTR wide_string = new WCHAR[my_str.size()+1]; //define an array with size of my_str + 1
        wide_string = my_str.c_str();
        return wide_string;
    }

上面的函数是 LPCWSTR->std::string 和 string->LPCWSTR

    std::string Split(std::string s, std::string token,int pos)
    {
        if (token.length() == 0 || s.find(token) == std::string::npos)
            return (s);
    
        std::vector<std::string> ret;
        int size = 0;
    
        std::string delim = ",";
    
        auto start = 0U;
        auto end = s.find(delim);
        while (end != std::string::npos)
        {
            ret.resize(size + 1);
            ret[size] = s.substr(start, end - start);
            size = size + 1;
            start = end + delim.length();
            end = s.find(delim, start);
        }
    
        ret.resize(size + 1);
        ret[size] = s.substr(start, end);
        size = size + 1;
    
        return ret[pos];
    }
    
    LPCWSTR lpcwstr_split(const LPCWSTR lpcwstr, const int pos) {
        string targetStr = convLPCWSTRtostring(lpcwstr);
        string token = ",";
    
        std::string ret;
        ret = Split(targetStr, token,pos);
            LPCWSTR retl;
            retl = convstringtoLPCWSTR(ret);
            return(retl); 
        
    }
    

这是主要的打印功能。我想打印“123 456 789”，但这会打印“??? ??? ???”

    LPCWSTR test = L"123,456,789";
           m_api->LoggerOut(MT_RET_OK, L"%s %s %s", lpcwstr_split(test, 0), lpcwstr_split(test, 1), lpcwstr_split(test, 2));