A component subscribes to an event and memory grows over time. How can the subscription cause a leak?

How can event subscriptions cause memory leaks in .NET?

Shows how publisher-to-subscriber references can retain objects and how to clean up event-based lifetimes.

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In .NET, an event subscription usually means the publisher holds a reference to the subscriber delegate. If the publisher lives longer than the subscriber, that reference can keep the subscriber alive. For example, a short-lived view model or service that subscribes to a singleton event can remain in memory after it is logically done. I would unsubscribe at the right lifecycle point or avoid the long-lived event path if ownership is unclear.

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Reference ownership, event publisher lifetime, unsubscribe patterns, weak events, and leak diagnosis.

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An event publisher holds subscriber delegates. When the publisher outlives a subscriber, that reference can retain the subscriber and its object graph long after the logical operation or UI lifetime has ended.
In .NET, an event subscription usually means the publisher holds a reference to the subscriber delegate. If the publisher lives longer than the subscriber, that reference can keep the subscriber alive. For example, a short-lived view model or service that subscribes to a singleton event can remain in memory after it is logically done. I would unsubscribe at the right lifecycle point or avoid the long-lived event path if ownership is unclear.
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I would explain it as a reference graph problem. The subscriber may disappear from the UI or request flow, but the publisher still has a delegate pointing to it, so the GC sees it as reachable. The fix depends on the design: unsubscribe in Dispose, use a scoped publisher, use weak-event patterns in UI-style code, or replace broad events with explicit callbacks that have a clear owner. I would also check lambdas because anonymous handlers are easy to subscribe and hard to remove correctly.

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Subscribing short-lived objects to singleton events.
Using anonymous handlers that cannot be removed easily.
Assuming the subscriber disappears when it leaves the UI or request.
Adding weak references without understanding ownership.

A component subscribes to an event and memory grows over time. How can the subscription cause a leak?

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