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# setActionQueue:action:

Sets the action to perform on the specified dispatch queue when the slider’s value changes.

```
- (void) setActionQueue:(dispatch_queue_t) actionQueue action:(void (^)(float newValue)) action;
```

## Parameters

`actionQueue`

A dispatch queue on which to call the action.

`action`

The action to perform in response to changes to the slider’s value.

## Discussion

If the action modifies a property of the camera system, the specified dispatch queue must represent the camera system’s same exclusive execution context (see <doc://com.apple.documentation/documentation/Swift/SerialExecutor/isSameExclusiveExecutionContext(other:)>).

---

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