public static extern int SCardGetStatusChange(IntPtr hContext,
int value_Timeout,
ref SCARD_READERSTATE ReaderState,
uint ReaderCount);
public static extern int SCardGetStatusChange(IntPtr hContext, int value_Timeout, ref SCARD_READERSTATE ReaderState, uint ReaderCount);
private async Task CardDetectionLoop(CancellationToken token)
{
await Task.Delay(1, token)
.ConfigureAwait(false); // resume on threadpool thread
while (!token.IsCancellationRequested)
{
try
{
var currentState = new SCARD_READERSTATE
{
RdrName = Name,
RdrCurrState = Constants.SCARD_STATE_UNAWARE,
RdrEventState = 0
};
const int readerCount = 1;
const int timeout = 0;
var retval = SafeNativeMethods.SCardGetStatusChange(hContext, timeout, ref currentState, readerCount);
if (retval == 0 && currentState.ATRLength > 0)
{
// Card inserted
if (!cardInserted)
{
cardInserted = true;
OnDisconnect(); // clean up if needed
var card = new SmartCard(hContext, Name, currentState.ATRValue);
if (Interlocked.CompareExchange(ref currentCard, card, null) == null)
{
// card was not inserted, now it is
// Raise on another thread to not block this loop
var evt = CardAdded;
if (evt != null)
{
Task.Run(() => evt(this, new CardAddedEventArgs(card)));
}
}
}
}
else
{
// Card removed
if (cardInserted)
{
cardInserted = false;
// HACK: Let our tranceive method know it's gone for one buggy reader
// bug in the 5427 CK reader
if (Name.Contains("5427 CK"))
{
SmartCardConnectionExtension.IsFirstConnection = false;
}
OnDisconnect();
}
}
await Task.Delay(250, token);
}
catch (Exception ex)
{
Debug.WriteLine("Exception from card monitor thread: " + ex);
}
}
}