Unicode下wstring(wchar_t*)和string(char*)互相转换

    #include<string>  
    using namespace std;  

    //将string转换成wstring  
    wstring string2wstring(string str)  
    {  
        wstring result;  
        //获取缓冲区大小，并申请空间，缓冲区大小按字符计算  
        int len = MultiByteToWideChar(CP_ACP, 0, str.c_str(), str.size(), NULL, 0);  
        TCHAR* buffer = new TCHAR[len + 1];  
        //多字节编码转换成宽字节编码  
        MultiByteToWideChar(CP_ACP, 0, str.c_str(), str.size(), buffer, len);  
        buffer[len] = '\0';             //添加字符串结尾  
        //删除缓冲区并返回值  
        result.append(buffer);  
        delete[] buffer;  
        return result;  
    }  

    //将wstring转换成string  
    string wstring2string(wstring wstr)  
    {  
        string result;  
        //获取缓冲区大小，并申请空间，缓冲区大小事按字节计算的  
        int len = WideCharToMultiByte(CP_ACP, 0, wstr.c_str(), wstr.size(), NULL, 0, NULL, NULL);  
        char* buffer = new char[len + 1];  
        //宽字节编码转换成多字节编码  
        WideCharToMultiByte(CP_ACP, 0, wstr.c_str(), wstr.size(), buffer, len, NULL, NULL);  
        buffer[len] = '\0';  
        //删除缓冲区并返回值  
        result.append(buffer);  
        delete[] buffer;  
        return result;  
    }