NetworkInformation.NetworkStatusChanged | networkstatuschanged event

function onNetworkStatusChanged(eventArgs) { /* Your code */ }
 
// addEventListener syntax
networkInformation.addEventListener("networkstatuschanged", onNetworkStatusChanged);
networkInformation.removeEventListener("networkstatuschanged", onNetworkStatusChanged);
 
- or -

networkInformation.onnetworkstatuschanged = onNetworkStatusChanged;