internal NfcTag(IntPtr handle)
{
_tagHandle = handle;
_nativeTransceiveCallback = TransceiveCompletedCallback;
_nativeVoidCallback = VoidCallback;
_nativeTagReadCallback = ReadNdefCallback;
}
/// <summary>
/// Reads the NDEF formatted data from the NFC tag.
/// </summary>
/// <since_tizen> 3 </since_tizen>
/// <privilege>http://tizen.org/privilege/nfc</privilege>
/// <exception cref="NotSupportedException">Thrown when the NFC is not supported.</exception>
/// <exception cref="InvalidOperationException">Thrown when the method fails due to an invalid operation.</exception>
public Task <NfcNdefMessage> ReadNdefMessageAsync()
{
var task = new TaskCompletionSource <NfcNdefMessage>();
NfcNdefMessage ndefMsg = null;
Interop.Nfc.TagReadCompletedCallback callback = (int result, IntPtr ndefMessage, IntPtr userData) =>
{
if (result == (int)NfcError.None)
{
ndefMsg = new NfcNdefMessage(ndefMessage);
task.SetResult(ndefMsg);
return(true);
}
return(false);
};
int ret = Interop.Nfc.Tag.ReadNdef(_tagHandle, callback, IntPtr.Zero);
if (ret != (int)NfcError.None)
{
Log.Error(Globals.LogTag, "Failed to read ndef message, Error - " + (NfcError)ret);
NfcErrorFactory.ThrowNfcException(ret);
}
return(task.Task);
}
/// <summary>
/// Constructor of NfcTag
/// </summary>
public NfcTag()
{
// A method is need to convert delegate to pass unmanaged layer through Interop call
// If we do not convert explicitly it, implicitly convert was occurred
// and temporal delegate was created. and it could be released by GC
_nativeTransceiveCallback = TransceiveCompletedCallback;
_nativeVoidCallback = VoidCallback;
_nativeTagReadCallback = ReadNdefCallback;
}
