/// <summary>
/// Communicates a request for cancellation.
/// </summary>
public void Cancel()
{
if (ProcessingVerb == null)
{
return;
}
isCanceled = true;
ProcessingVerb.Cancel();
}
/// <summary>
/// Processes.
/// </summary>
/// <param name="args">The arguments.</param>
/// <param name="resetCancelState">true if need to reset the cancel state; otherwise, false.</param>
/// <returns>The verb handler.</returns>
private async Task <Verb> ProcessAsync(Arguments args, bool resetCancelState)
{
if (isCanceled)
{
if (resetCancelState)
{
isCanceled = false;
}
return(null);
}
var verb = PrepareVerb(args);
if (verb == null)
{
return(null);
}
if (ProcessingVerb != null && !ProcessingVerb.HasDisposed)
{
try
{
if (!ProcessingVerb.IsCancelled)
{
ProcessingVerb.Cancel();
}
}
catch (NullReferenceException)
{
}
catch (InvalidOperationException)
{
}
catch (ArgumentException)
{
}
catch (OperationCanceledException)
{
}
finally
{
ProcessingVerb.Dispose();
}
}
if (ProcessingVerb == verb)
{
return(null);
}
ProcessingVerb = verb;
Processing?.Invoke(this, new ProcessEventArgs(args, verb));
try
{
if (!verb.IsCancelled && !isCanceled && !verb.HasDisposed)
{
verb.Init(this);
}
if (!verb.IsCancelled && !isCanceled && !verb.HasDisposed)
{
if (verb is AsyncVerb asyncVerb)
{
await asyncVerb.ProcessAsync();
}
else
{
verb.Process();
}
}
else if (resetCancelState)
{
isCanceled = false;
}
Processed?.Invoke(this, new ProcessEventArgs(args, verb));
}
catch (OperationCanceledException ex)
{
ProcessCanceled?.Invoke(this, new FailedProcessEventArgs(args, verb, ex));
}
catch (Exception ex)
{
ProcessFailed?.Invoke(this, new FailedProcessEventArgs(args, verb, ex));
throw ex;
}
finally
{
verb.Dispose();
ProcessingVerb = null;
}
return(verb);
}
