/// <summary>
/// Enumerates NFC reader and registers event handlers for card added/removed
/// </summary>
/// <returns>None</returns>
private async void GetDevices()
{
try
{
reader = await CardReader.FindAsync();
if (reader == null)
{
PopupMessage("No Readers Found");
return;
}
reader.CardAdded += CardAdded;
reader.CardRemoved += CardRemoved;
}
catch (Exception e)
{
PopupMessage("Exception: " + e.Message);
}
}
private static async void OnCardAdded(SmartCardReader sender, CardAddedEventArgs args)
{
try
{
await HandleCard(args.SmartCard);
// Raise on UI thread
context.Post(_ =>
{
var evt = cardAdded;
if (evt != null)
evt(sender, EventArgs.Empty);
}, null);
}
catch (Exception ex)
{
// TODO: Add logging
Debug.WriteLine(ex);
}
}
private static void OnCardRemoved(SmartCardReader sender, CardRemovedEventArgs args)
{
lock (cardConnectionLock)
{
if (currentConnection != null)
{
currentConnection.Dispose();
currentConnection = null;
currentCardId = null;
}
}
// Let users know the card is gone
// Raise on UI thread
context.Post(_ =>
{
var evt = cardRemoved;
if (evt != null)
evt(sender, EventArgs.Empty);
}, null);
}
public static async Task Initialize()
{
// Clear out any old event handlers
cardAdded = null;
cardRemoved = null;
if(reader != null)
return;
context = SynchronizationContext.Current;
var r = await CardReader.FindAsync();
if (r != null)
{
reader = r;
reader.CardAdded += OnCardAdded;
reader.CardRemoved += OnCardRemoved;
}
}