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# startInteractiveTransition(_:)

Called when the system needs to set up the interactive portions of a view controller transition and start the animations.

```
func startInteractiveTransition(_ transitionContext: any UIViewControllerContextTransitioning)
```

## Parameters

`transitionContext`

The context object containing information about the transition.

## Discussion

Your implementation of this method should use the data in the `transitionContext` parameter to configure user interactivity for the transition and then start the animations. While tracking user interactions, your event handling code should regularly call the context object’s [`updateInteractiveTransition(_:)`](/documentation/UIKit/UIViewControllerContextTransitioning/updateInteractiveTransition(_:)) method to report on how much of the transition is now complete. If events indicate that the user has canceled the transition, call the [`cancelInteractiveTransition()`](/documentation/UIKit/UIViewControllerContextTransitioning/cancelInteractiveTransition()) method. If events indicate that the transition has finished, call the [`finishInteractiveTransition()`](/documentation/UIKit/UIViewControllerContextTransitioning/finishInteractiveTransition()) method.

---

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