private async void HandleWiteTag(INFCMiFareTag nMifareTag)
{
byte[] data = await Read4Pages(nMifareTag, 0);
// write
if (data != null)
{
byte[] FirstTag = MainTabViewModel.Current?.DataBag.GetData();
byte[] mem = new byte[80];
data.CopyTo(mem, 0);
byte[] dstData = MainTabViewModel.MergeTagData(FirstTag, mem);
bool result = true;
for (byte i = 4; result && (i < 16); i++)
{
result = await WritePage(nMifareTag, i, dstData.Skip(4 * i).Take(4).ToArray());
}
if (result)
{
MainTabViewModel.Current?.DataBag.SetData(dstData);
}
}
MainTabViewModel.Current.cbNFCRead = false;
MainTabViewModel.Current.cbNFCWrite = false;
}
internal void CheckForNfcMessage(Intent intent)
{
if (!Enabled)
{
return;
}
if (intent.Action != NfcAdapter.ActionTechDiscovered)
{
return;
}
if (!(intent.GetParcelableExtra(NfcAdapter.ExtraTag) is Tag tag))
{
return;
}
try
{
var ev1 = MifareUltralight.Get(tag);
//TagDetected?.Invoke(tag);
ev1.Connect();
byte[] FirstTag = MainTabViewModel.Current?.DataBag.GetData();
byte[] mem = new byte[80];
for (int i = 0; i < 20; i += 4)
{
byte[] payload = ev1.ReadPages(i);
Buffer.BlockCopy(payload, 0, mem, 4 * i, 16);
}
if (WriteMode)
{
byte[] dstData = MainTabViewModel.MergeTagData(FirstTag, mem);
// password auth
// var response = ev1.Transceive(new byte[]{
// (byte) 0x1B, // PWD_AUTH
// 0,0,0,0 });
// Check if PACK is matching expected PACK
// This is a (not that) secure method to check if tag is genuine
//if ((response != null) && (response.Length >= 2))
//{
//}
for (int i = 4; i < 16; i++)
{
ev1.WritePage(i, dstData.Skip(4 * i).Take(4).ToArray());
}
MainTabViewModel.Current?.DataBag.SetData(dstData);
WriteMode = false;
}
else
{
MainTabViewModel.Current?.SetControlsVisibility(mem[41]);
MainTabViewModel.Current?.DataBag.SetData(mem);
}
ev1.Close();
MainTabViewModel.Current.cbNFCRead = false;
MainTabViewModel.Current.cbNFCWrite = false;
try
{
// Use default vibration length
Vibration.Vibrate();
}
catch (FeatureNotSupportedException ex)
{
// Feature not supported on device
}
catch (Exception ex)
{
// Other error has occurred.
}
}
catch (Exception e)
{
try
{
Vibration.Vibrate();
Thread.Sleep(1000);
Vibration.Vibrate();
}
catch (Exception ex)
{
// Other error has occurred.
}
}
}