恶心的CString转string，char*

/*
 * 函数名: CString2Char
 * 参数1: CString str                    待转换字符串
 * 参数2: char ch[]                        转换后将要储存的位置
 * 将Unicode下的CString转换为char*
 */
void CString2Char(CString str, char ch[])
{
    int i;
    char *tmpch;
    int wLen = WideCharToMultiByte(CP_ACP, 0, str, -1, NULL, 0, NULL, NULL);//得到Char的长度
    tmpch = new char[wLen + 1];                                             //分配变量的地址大小
    WideCharToMultiByte(CP_ACP, 0, str, -1, tmpch, wLen, NULL, NULL);       //将CString转换成char*
    
    for(i = 0; tmpch[i] != '\0'; i++) ch[i] = tmpch[i];
    ch[i] = '\0';
}