How to detect network change events asynchronously using c++ WinRT

Question

networkStatusCallback = new NetworkStatusChangedEventHandler(OnNetworkStatusChange);
    if (!registeredNetworkStatusNotif)
    {
        NetworkInformation.NetworkStatusChanged += networkStatusCallback;
        registeredNetworkStatusNotif = true;
    }

I'm getting the error NetworkInformation.NetworkStatusChanged += networkStatusCallback

Answer 1

This will get you started. It's some code I cobbled together.

It doesn't do error checking. You should check the HRESULT or error code from each major function invoked below.

It doesn't show you how to implement INetworkStatusChangedEventHandler. You have to implement an implementation of that class yourself using the standard COM principals.

You'll need to link with runtimeobjects.lib for RoGetActivationFactory.

#include <windows.h>
#include <roapi.h>
#include <Windows.Networking.h>
#include <Windows.Networking.Connectivity.h>

using ABI::Windows::Networking::Connectivity::INetworkInformationStatics;
using ABI::Windows::Networking::Connectivity::INetworkStatusChangedEventHandler;

int main()
{
    CoInitialize(nullptr);
    HSTRING hstr = nullptr;
    IActivationFactory* pFactory = nullptr;
    INetworkInformationStatics* pStatics = nullptr;
    EventRegistrationToken token = {};

    const wchar_t* interfaceName = RuntimeClass_Windows_Networking_Connectivity_NetworkInformation;
    ::WindowsCreateString(interfaceName, (DWORD)(wcslen(interfaceName)), &hstr);

    ::RoGetActivationFactory(hstr, IID_IActivationFactory, (void**)&pFactory);
    WindowsDeleteString(hstr);

    INetworkStatusChangedEventHandler* pHandler = <ptr to com object you create that implements INetworkStatusChangedEventHandler>

    pFactory->QueryInterface(&pStatics);

    pStatics->add_NetworkStatusChanged(pHandler, &token);

    return 0;
}