/// <summary>
/// Clears the alert callback and stops reporting changes.
/// </summary>
/// <exception cref="NotSupportedException">IsUserGpio is false.</exception>
public void Stop()
{
ValidateAvailable();
lock (SyncLock)
{
// TODO: For some reason passing NULL to cancel the alert makes everything hang!
// This looks like a bug in the pigpio library.
BoardException.ValidateResult(
IO.GpioSetAlertFunc((UserGpio)Pin.PinNumber, (g, l, t) => { }));
Callback = null;
}
}
/// <summary>
/// Start the alert callbacks.
/// </summary>
/// <param name="callback">The callback.</param>
/// <exception cref="NotSupportedException">IsUserGpio is false.</exception>
/// <exception cref="ArgumentNullException">callback - ClearAlertCallback.</exception>
/// <exception cref="ArgumentException">A callback is already registered. Clear the current callback before registering a new one. - callback.</exception>
public void Start(PiGpioAlertDelegate callback)
{
ValidateAvailable();
if (callback == null)
{
throw new ArgumentNullException(nameof(callback), $"The callback cannot be null. Use the '{nameof(Stop)}' method instead.");
}
lock (SyncLock)
{
if (Callback != null)
{
throw new ArgumentException("A callback is already registered. Clear the current callback before registering a new one.", nameof(callback));
}
BoardException.ValidateResult(
IO.GpioSetAlertFunc((UserGpio)Pin.PinNumber, callback));
Callback = callback;
}
}
public static extern ResultCode GpioSetAlertFunc(UserGpio userGpio, [In, MarshalAs(UnmanagedType.FunctionPtr)] PiGpioAlertDelegate callback);
