ScrollView in React Native | React Native Episodes | JAS ACADAMY

The ScrollView is a generic scrollable container, which scrolls multiple child components and views inside it. In the ScrollView, we can scroll the components in both direction vertically and horizontally. By default, the ScrollView container scrolls its components and views in vertical. To scroll its components in horizontal, it uses the props horizontal: true (default, horizontal: false).


keep in mind that ScrollViews must have a bounded height in order to work, since they contain unbounded-height children into a bounded container (via a scroll interaction). In order to bound the height of a ScrollView, either set the height of the view directly (discouraged) or make sure all parent views have bounded height. Forgetting to transfer {flex: 1} down the view stack can lead to errors here, which the element inspector makes quick to debug.

Doesn't yet support other contained responders from blocking this scroll view from becoming the responder.

ScrollView vs FlatList - which one to use?

ScrollView renders all its react child components at once, but this has a performance downside.

Imagine you have a very long list of items you want to display, maybe several screens worth of content. Creating JS components and native views for everything all at once, much of which may not even be shown, will contribute to slow rendering and increased memory usage.

This is where FlatList comes into play. FlatList renders items lazily, when they are about to appear, and removes items that scroll way off screen to save memory and processing time.

FlatList is also handy if you want to render separators between your items, multiple columns, infinite scroll loading, or any number of other features it supports out of the box.