注意事项

注意：①64位操作系统注册表会重定向，RegOpenKeyEx第4个参数得加上KEY_WOW64_64KEY；②RegOpenKeyEx遍历子项时注意第2和第4参数，参考图：

③RegQueryValueEx同样得注意第6参数

完整代码

std::unordered_map<std::string, std::string> GetAllAutoCADInstallPaths() 
{
	// 定义结果映射，键为版本号，值为安装路径
	std::unordered_map<std::string, std::string> installPaths;

	// 打开 AutoCAD 注册表项
	HKEY hKey;
	LONG lResult = RegOpenKeyEx(HKEY_LOCAL_MACHINE, "SOFTWARE\\Autodesk\\AutoCAD", 0, KEY_READ | KEY_WOW64_64KEY, &hKey);
	if (lResult != ERROR_SUCCESS) return installPaths;

	DWORD dwIndex = 0;
	TCHAR szSubKeyName[MAX_PATH];
	DWORD dwSize = sizeof(szSubKeyName);

	vector<string> vecSubKey;
	// 遍历子项
	while ((lResult = RegEnumKeyEx(hKey, dwIndex, szSubKeyName, &dwSize, NULL, NULL, NULL, NULL)) == ERROR_SUCCESS) 
	{
		vecSubKey.emplace_back(string("SOFTWARE\\Autodesk\\AutoCAD\\")+szSubKeyName);
		++dwIndex;
		dwSize = MAX_PATH;
	}

	vector<string> vecSubSubKey;
	for (auto &strKey : vecSubKey)
	{
		HKEY hSubKey;
		LONG lResult = RegOpenKeyEx(HKEY_LOCAL_MACHINE, strKey.c_str(), 0, KEY_READ | KEY_WOW64_64KEY, &hSubKey);
		if (lResult != ERROR_SUCCESS) return installPaths;
		
		dwIndex = 0;
		while ((lResult = RegEnumKeyEx(hSubKey, dwIndex, szSubKeyName, &dwSize, NULL, NULL, NULL, NULL)) == ERROR_SUCCESS) 
		{
			vecSubSubKey.emplace_back(strKey + "\\" + szSubKeyName);
			++dwIndex;
			dwSize = MAX_PATH;
		}

		// 关闭键
		RegCloseKey(hSubKey);
	}


	for(auto &strKey : vecSubSubKey)
	{
		HKEY hSubKey;
		LONG lResult = RegOpenKeyEx(HKEY_LOCAL_MACHINE, strKey.c_str(), 0, KEY_READ| KEY_WOW64_64KEY, &hSubKey);
		if (lResult != ERROR_SUCCESS) return installPaths;
		
		char installPath[MAX_PATH];
		char name[MAX_PATH];
		DWORD size = MAX_PATH;
		if(RegQueryValueEx(hSubKey, "Location", NULL, NULL, reinterpret_cast<LPBYTE>(installPath), &size) == ERROR_SUCCESS) 
		{
			size = MAX_PATH;
			RegQueryValueEx(hSubKey, "ProductName", NULL, NULL, reinterpret_cast<LPBYTE>(name), &size);
			installPaths[string(name)] = string(installPath);;
		}

		// 关闭键
		RegCloseKey(hSubKey);
	}

	// 关闭键
	RegCloseKey(hKey);
	return installPaths;
}