/// <summary>
/// Registers a delegate that will be called when this System.Threading.CancellationToken is canceled.
/// </summary>
/// <param name="callback">The delegate to be executed when the System.Threading.CancellationToken is canceled.</param>
/// <param name="useSynchronizationContext">A value that indicates whether to capture the current System.Threading.SynchronizationContext and use it when invoking the callback.</param>
/// <returns>The System.Threading.CancellationTokenRegistration instance that can be used to deregister the callback.</returns>
/// <exception cref="System.ArgumentNullException">callback is null</exception>
public CancellationTokenRegistration Register(Action callback, bool useSynchronizationContext)
{
callback = callback ?? throw new ArgumentNullException("callback");
if (source.IsCancellationRequested)
{
callback();
}
else if (source != null)
{
return(source.NotifyOnCancelled(callback, useSynchronizationContext));
}
return(new CancellationTokenRegistration());
}
