---
title: "setUserCallback(_:)"
framework: avfaudio
role: symbol
role_heading: Instance Method
path: "avfaudio/avaudiosequencer/setusercallback(_:)"
---

# setUserCallback(_:)

Adds a callback that the sequencer calls each time it encounters a user event during playback.

## Declaration

```swift
func setUserCallback(_ userCallback: AVAudioSequencerUserCallback?)
```

## Parameters

- `userCallback`: The user callback that the system calls.

## Discussion

Discussion The system calls the same callback for events that occur on any track in the sequencer. Set the callback to nil to disable it.

## See Also

### Setting the User Callback

- [AVAudioSequencerUserCallback](avfaudio/avaudiosequencerusercallback.md)