VS c++判斷網絡是否正常

BOOL checkIsNetwork()
{
	CoInitialize(NULL);
	//  通過NLA接口獲取網絡狀態
	IUnknown *pUnknown = NULL;
	BOOL bOnline = true;//是否在線  
	HRESULT Result = CoCreateInstance(CLSID_NetworkListManager, NULL, CLSCTX_ALL, IID_IUnknown, (void **)&pUnknown);
	if (SUCCEEDED(Result))
	{
		INetworkListManager *pNetworkListManager = NULL;
		if (pUnknown)
			Result = pUnknown->QueryInterface(IID_INetworkListManager, (void **)&pNetworkListManager);
		if (SUCCEEDED(Result))
		{
			VARIANT_BOOL IsConnect = VARIANT_FALSE;
			if (pNetworkListManager)
				Result = pNetworkListManager->get_IsConnectedToInternet(&IsConnect);
			if (SUCCEEDED(Result))
			{
				bOnline = (IsConnect == VARIANT_TRUE) ? true : false;
			}


		}
		if (pNetworkListManager)
			pNetworkListManager->Release();
	}
	if (pUnknown)
		pUnknown->Release();
	CoUninitialize();
	return bOnline;
}