public HubManager(ServerConnectionSettings connectionSettings)
{
_connection = new HubConnectionBuilder()
.WithUrl($"{connectionSettings.ServerURL}/notification")
.WithAutomaticReconnect()
.Build();
_connection.On <string>("botnewjobnotification", (agentId) => JobNotificationReceived?.Invoke(agentId));
}
/// <summary>
/// Checks printer(s) for notifications.
/// </summary>
private void ListenForChanges()
{
// Check for cancellation.
_cancelSource.Token.ThrowIfCancellationRequested();
SafePrinterChangeNotificationHandle hChange = null;
try
{
hChange = WaitForMultipleObjects(_hChanges);
}
catch (TimeoutException)
{
// No object changed within the timeout period.
// This could mean that there was really no change,
// or because the spooler is no longer sending updates to us.
// Since we can't tell the difference, clean up existing structures and sign up for events again.
// If the cancel token has been set, it might be a bit before we get back to checking it again,
// so check it here before resetting. If it has been set, bail out so the monitor can stop.
_cancelSource.Token.ThrowIfCancellationRequested();
LogDebug("No job changes detected. Resetting listener.");
Reset();
Initialize();
return;
}
catch (ArgumentOutOfRangeException ex)
{
// Unsuccessful in getting the change notification handle. Bail out.
LogDebug(ex);
return;
}
// WaitForMultipleObjects could have taken a while, so check for cancellation again.
_cancelSource.Token.ThrowIfCancellationRequested();
// Get the notify information that changed.
PrinterNotifyInfoReader infoReader = FindNextPrinterChangeNotification(hChange);
if (infoReader == null)
{
LogDebug("Lost job data. Trying a refresh.");
infoReader = FindNextPrinterChangeNotification(hChange, _options);
}
using (infoReader)
{
foreach (PrinterNotifyInfoData infoData in infoReader.ReadInfoData())
{
if (infoData.NotifyType == NotifyType.Job)
{
JobNotificationReceived?.Invoke(this, new JobNotificationEventArgs(infoData));
}
}
}
}
