NetworkChange.NetworkAddressChanged事件不会触发

Question

I am developing a windows phone 7 app which is required to work with network.

I wanted my application to connect when NetworkAddress is changed that it becomes available. So I used NetworkChange.Networkaddresschanged. I was testing my app on emulator. It fires up first time but as there is no network I do nothing. This NetworkAddresschanged does not fire up the second time when network is available.

My code is

    public void OnNetworkDownEvent()
    {
        lock (_networkChange)
        {
            var handler =_OnNetworkDown;
            if (handler != null)
            {
                _OnNetworkDown();
            }
            Deployment.Current.Dispatcher.BeginInvoke(() =>
            {
                NetworkChange.NetworkAddressChanged -= OnNetworkChange;
                NetworkChange.NetworkAddressChanged += OnNetworkChange;
            });


            _connectionDown = true;

            Monitor.Wait(_networkChange);
            OnNetworkUpEvent();
        }
    }


    public void OnNetworkUpEvent()
    {
        var handler = _OnNetworkUp;
        if (handler != null)
        {
            _OnNetworkUp();



        }
    }

    private void OnNetworkChange(object sender, EventArgs e)
    {
        lock(_networkChange)
        {
            if(NetworkInterface.GetIsNetworkAvailable())
            {

                if (_connectionDown)
                {
                    _connectionDown = false;
                    Monitor.Pulse(_networkChange);
                    //OnNetworkUpEvent();
                }
            }
        }
    }

I call Networkdownevent() when network is down.And at that time I attach a delegate to NetworkAddressChange.

I do not know why this is happening.

Answer 1

The phone will see the USB connection to the host PC as it's primary connection so changes to the network connection of the attached PC will not have an impact on the phone.

This is one scenario where you can't test with the debugger attached. You'll have to store/display your debug output on the device with it not attached.
For testing I recommend having the phone connect to WiFi only and then controlling the connection state by turning the access point on or off. (This is the simplest technique I'm aware of for such a situation.)