👀 Views: 100 💬 Answers: 1 📅 Created: 2025-06-12

prism wpf event-aggregator C#

I've been banging my head against this for hours... I'm using Prism 8 for managing event-driven communication between different modules in my WPF application, and I've run into a perplexing issue. I have a simple event aggregator setup where one view model publishes an event, and another subscribes to that event. However, I notice that sometimes the subscriber does not receive the event when it should. This inconsistency is causing some serious bugs in my application. Here's a brief look at my code: **Publisher Code:** ```csharp public class PublisherViewModel : BindableBase { private readonly IEventAggregator _eventAggregator; public PublisherViewModel(IEventAggregator eventAggregator) { _eventAggregator = eventAggregator; } public void PublishEvent() { var message = "Hello from Publisher!"; _eventAggregator.GetEvent<SimpleEvent>().Publish(message); } } ``` **Subscriber Code:** ```csharp public class SubscriberViewModel : BindableBase { private readonly IEventAggregator _eventAggregator; public string ReceivedMessage { get; private set; } public SubscriberViewModel(IEventAggregator eventAggregator) { _eventAggregator = eventAggregator; _eventAggregator.GetEvent<SimpleEvent>().Subscribe(OnMessageReceived); } private void OnMessageReceived(string message) { ReceivedMessage = message; } } ``` The issue arises primarily when I try to publish events in quick succession. For instance, if I call `PublishEvent()` multiple times within a loop, only the last message seems to be processed by the subscriber, and earlier messages get lost. Additionally, I have verified that both the publisher and subscriber are instantiated correctly and that the `IEventAggregator` instance is the same. I've tried debugging by adding logging within the `OnMessageReceived` method, which confirms that it's not being invoked for every published message. I also considered whether the subscriber might be getting garbage collected, but I've ensured it's held in memory properly. Any insights on why events might not be consistently received in this setup? Are there best practices I should be following when using the Event Aggregator pattern in Prism, especially when handling rapid event publishing? I'm working on a web app that needs to handle this.