public virtual SubscriptionToken Subscribe(Action <TPayload> action, ThreadOption threadOption, bool keepSubscriberReferenceAlive, Predicate <TPayload> filter) { var actionReference = (IDelegateReference) new DelegateReference(action, keepSubscriberReferenceAlive); var filterReference = filter == null ? (IDelegateReference) new DelegateReference((Predicate <TPayload>)(predicate => true), true) : new DelegateReference(filter, keepSubscriberReferenceAlive); EventSubscription <TPayload> eventSubscription; switch (threadOption) { case ThreadOption.PublisherThread: eventSubscription = new EventSubscription <TPayload>(actionReference, filterReference); break; case ThreadOption.UIThread: if (this.SynchronizationContext == null) { throw new InvalidOperationException(Resources.EventAggregatorNotConstructedOnUIThread); } eventSubscription = new DispatcherEventSubscription <TPayload>(actionReference, filterReference, this.SynchronizationContext); break; case ThreadOption.BackgroundThread: eventSubscription = new BackgroundEventSubscription <TPayload>(actionReference, filterReference); break; default: eventSubscription = new EventSubscription <TPayload>(actionReference, filterReference); break; } return(this.InternalSubscribe(eventSubscription)); }
/// <summary> /// Subscribes a delegate to an event. /// </summary> /// <param name="action">The delegate that gets executed when the event is published.</param> /// <param name="threadOption">Specifies on which thread to receive the delegate callback.</param> /// <param name="keepSubscriberReferenceAlive">When <see langword="true"/>, the <see cref="PubSubEvent"/> keeps a reference to the subscriber so it does not get garbage collected.</param> /// <returns>A <see cref="SubscriptionToken"/> that uniquely identifies the added subscription.</returns> /// <remarks> /// If <paramref name="keepSubscriberReferenceAlive"/> is set to <see langword="false" />, <see cref="PubSubEvent"/> will maintain a <see cref="WeakReference"/> to the Target of the supplied <paramref name="action"/> delegate. /// If not using a WeakReference (<paramref name="keepSubscriberReferenceAlive"/> is <see langword="true" />), the user must explicitly call Unsubscribe for the event when disposing the subscriber in order to avoid memory leaks or unexpected behavior. /// <para/> /// The PubSubEvent collection is thread-safe. /// </remarks> public virtual SubscriptionToken Subscribe(Action action, ThreadOption threadOption, bool keepSubscriberReferenceAlive) { var actionReference = new DelegateReference(action, keepSubscriberReferenceAlive); EventSubscription subscription; switch (threadOption) { case ThreadOption.PublisherThread: subscription = new EventSubscription(actionReference); break; case ThreadOption.BackgroundThread: subscription = new BackgroundEventSubscription(actionReference); break; case ThreadOption.UIThread: if (this.SynchronizationContext == null) { throw new InvalidOperationException(Resources.EventAggregatorNotConstructedOnUIThread); } subscription = new DispatcherEventSubscription(actionReference, this.SynchronizationContext); break; default: subscription = new EventSubscription(actionReference); break; } return(this.InternalSubscribe(subscription)); }