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virtualizedlist |
VirtualizedList |
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Base implementation for the more convenient <FlatList>
and <SectionList>
components, which are also better
documented. In general, this should only really be used if you need more flexibility than
FlatList
provides, e.g. for use with immutable data instead of plain arrays.
Virtualization massively improves memory consumption and performance of large lists by
maintaining a finite render window of active items and replacing all items outside of the render
window with appropriately sized blank space. The window adapts to scrolling behavior, and items
are rendered incrementally with low-pri (after any running interactions) if they are far from the
visible area, or with hi-pri otherwise to minimize the potential of seeing blank space.
Some caveats:
- Internal state is not preserved when content scrolls out of the render window. Make sure all
your data is captured in the item data or external stores like Flux, Redux, or Relay.
- This is a
PureComponent
which means that it will not re-render if props
remain shallow-
equal. Make sure that everything your renderItem
function depends on is passed as a prop
(e.g. extraData
) that is not ===
after updates, otherwise your UI may not update on
changes. This includes the data
prop and parent component state.
- In order to constrain memory and enable smooth scrolling, content is rendered asynchronously
offscreen. This means it's possible to scroll faster than the fill rate ands momentarily see
blank content. This is a tradeoff that can be adjusted to suit the needs of each application,
and we are working on improving it behind the scenes.
- By default, the list looks for a
key
prop on each item and uses that for the React key.
Alternatively, you can provide a custom keyExtractor
prop.
Props
Methods
Type Definitions
Reference
Props
last
first
horizontal
initialNumToRender
disableVirtualization
maxToRenderPerBatch
onEndReachedThreshold
scrollEventThrottle
updateCellsBatchingPeriod
windowSize
Methods
scrollToEnd()
scrollToEnd([params]: object)
scrollToIndex()
scrollToIndex(params: object)
scrollToItem()
scrollToItem(params: object)
scrollToOffset()
scrollToOffset(params: object)
Scroll to a specific content pixel offset in the list.
Param offset
expects the offset to scroll to.
In case of horizontal
is true, the offset is the x-value,
in any other case the offset is the y-value.
Param animated
(true
by default) defines whether the list
should do an animation while scrolling.
recordInteraction()
recordInteraction()
flashScrollIndicators()
flashScrollIndicators()
Type Definitions
renderItemType
Type |
FunctionTypeAnnotation |
Props
Type |
IntersectionTypeAnnotation |