# IEvictionStrategy Properties

[Type overview](/orleans/docs/api/csharp/microsoft.orleans.streaming/orleans.providers.streams.common.ievictionstrategy/)

## OnPurged {#onpurged-7d6d1201}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.streaming/orleans.providers.streams.common.ievictionstrategy/properties/onpurged-7d6d1201/)

```csharp
public abstract Action<CachedMessage?, CachedMessage?> OnPurged
```

Gets or sets the method which will be called when purge is finished.

## PurgeObservable {#purgeobservable-2736b31e}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.streaming/orleans.providers.streams.common.ievictionstrategy/properties/purgeobservable-2736b31e/)

```csharp
public abstract IPurgeObservable PurgeObservable
```

Gets the [IPurgeObservable](/orleans/docs/api/csharp/microsoft.orleans.streaming/orleans.providers.streams.common.ipurgeobservable/), which is implemented by the cache to do purge related actions and invoked by the eviction strategy.