C++ 字符串的拼接的问题

Question

std::string path = "d:\a\b\" ;这是路径
wstring filename=L"h1";这是文件的名字
最终我想要的是d:\a\b\h1.txt 这个完整的路径

Answer 1

std::string WStringToString(const std::wstring &wstr)
{
    std::string str;
    int nLen = (int)wstr.length();
    str.resize(nLen, ' ');
    int nResult = WideCharToMultiByte(CP_ACP, 0, (LPCWSTR)wstr.c_str(), nLen, (LPSTR)str.c_str(), nLen, NULL, NULL);
    if (nResult == 0)
    {
        return "";
    }
    return str;
}

...............................................................
std::string path = "d:\\a\\b\\" ;
wstring filename=L"h1";
path=path+WStringToString(filename)+".txt";