---
title: "scrollViewWillBeginDecelerating(_:)"
framework: uikit
role: symbol
role_heading: Instance Method
path: "uikit/uiscrollviewdelegate/scrollviewwillbegindecelerating(_:)"
---

# scrollViewWillBeginDecelerating(_:)

Tells the delegate that the scroll view is starting to decelerate the scrolling movement.

## Declaration

```swift
optional func scrollViewWillBeginDecelerating(_ scrollView: UIScrollView)
```

## Parameters

- `scrollView`: The scroll-view object that’s decelerating the scrolling of the content view.

## Discussion

Discussion The scroll view calls this method as the user’s finger touches up as it’s moving during a scrolling operation; the scroll view continues to move a short distance afterwards. The isDecelerating property of UIScrollView controls deceleration.

## See Also

### Responding to scrolling and dragging

- [scrollViewDidScroll(_:)](uikit/uiscrollviewdelegate/scrollviewdidscroll(_:).md)
- [scrollViewWillBeginDragging(_:)](uikit/uiscrollviewdelegate/scrollviewwillbegindragging(_:).md)
- [scrollViewWillEndDragging(_:withVelocity:targetContentOffset:)](uikit/uiscrollviewdelegate/scrollviewwillenddragging(_:withvelocity:targetcontentoffset:).md)
- [scrollViewDidEndDragging(_:willDecelerate:)](uikit/uiscrollviewdelegate/scrollviewdidenddragging(_:willdecelerate:).md)
- [scrollViewShouldScrollToTop(_:)](uikit/uiscrollviewdelegate/scrollviewshouldscrolltotop(_:).md)
- [scrollViewDidScrollToTop(_:)](uikit/uiscrollviewdelegate/scrollviewdidscrolltotop(_:).md)
- [scrollViewDidEndDecelerating(_:)](uikit/uiscrollviewdelegate/scrollviewdidenddecelerating(_:).md)