/// <summary>
/// Cancels a subscription and releases all resources allocated for it.
/// </summary>
/// <param name="subscription">The subscription to cancel.</param>
public void CancelSubscription(ITsCDaSubscription subscription)
{
if (subscription == null)
{
throw new ArgumentNullException(nameof(subscription));
}
lock (this)
{
if (server_ == null)
{
throw new NotConnectedException();
}
string methodName = "IOPCServer.RemoveGroup";
// validate argument.
if (!typeof(Subscription).IsInstanceOfType(subscription))
{
throw new ArgumentException("Incorrect object type.", nameof(subscription));
}
// get the subscription state.
TsCDaSubscriptionState state = subscription.GetState();
if (!subscriptions_.ContainsKey(state.ServerHandle))
{
throw new ArgumentException("Handle not found.", nameof(subscription));
}
subscriptions_.Remove(state.ServerHandle);
// release all subscription resources.
subscription.Dispose();
// invoke COM method.
try
{
IOPCServer server = BeginComCall <IOPCServer>(methodName, true);
server.RemoveGroup((int)state.ServerHandle, 0);
if (DCOMCallWatchdog.IsCancelled)
{
throw new Exception($"{methodName} call was cancelled due to response timeout");
}
}
catch (Exception e)
{
ComCallError(methodName, e);
throw Utilities.Interop.CreateException(methodName, e);
}
finally
{
EndComCall(methodName);
}
}
}
/// <summary>
/// Returns the current subscription state.
/// </summary>
public TsCDaSubscriptionState GetState()
{
subscriptionState_ = Subscription.GetState();
return(subscriptionState_);
}
/// <summary>
/// Returns the current subscription state.
/// </summary>
public TsCDaSubscriptionState GetState()
{
_state = _subscription.GetState();
return(_state);
}