---
title: EXHostViewControllerDelegate
framework: extensionkit
role: symbol
role_heading: Protocol
path: extensionkit/exhostviewcontrollerdelegate
---

# EXHostViewControllerDelegate

An interface you use to track the activation and deactivation of an app extension.

## Declaration

```swift
protocol EXHostViewControllerDelegate : NSObjectProtocol
```

## Topics

### Responding to activation and deactivation events

- [hostViewControllerDidActivate(_:)](extensionkit/exhostviewcontrollerdelegate/hostviewcontrollerdidactivate(_:).md)
- [hostViewControllerWillDeactivate(_:error:)](extensionkit/exhostviewcontrollerdelegate/hostviewcontrollerwilldeactivate(_:error:).md)

## Relationships

### Inherits From

- [NSObjectProtocol](objectivec/nsobjectprotocol.md)

## See Also

### Responding to activation and deactivation events

- [delegate](extensionkit/exhostviewcontroller/delegate.md)