scrollToIndex and scrollToLocation not working on FlatList, SectionList

[ZeroJian]

scrollToIndex and scrollToLocation not working on FlatList, SectionList

Sample code: (url) https://snack.expo.io/I9cYUYxJi

Environment (include versions). Did this work in previous versions?

• "react": "16.13.1",
• "react-dom": "^17.0.1",
• "react-native": "0.63.3",
• "react-native-web": "^0.14.9",
• "expo": "^39.0.5",
• Browser: Chrome, Safari

[Spodera]

Same issue with electron :

My dependencies :

    "react-native-web": "^0.14.11",
    "electron": "^6.0.12",
    "expo": "^40.0.1",
    "react": "^17.0.1",
    "react-dom": "^17.0.1",
    "react-native": "^0.63.4",

[gusgard]

A work around I did is to define the function getItemLayout,

Example on expo: https://snack.expo.io/@gusgard/react-native-swiper-flatlist

Code:
https://github.com/gusgard/react-native-swiper-flatlist/blob/master/src/components/SwiperFlatList/SwiperFlatList.tsx#L236

[Redseb]

For some reason adding a delay of even 1 ms to the scrollToIndex call solved the issue for me on web.

I.e.

//...
setTimeout(()=>{
    flatListRef.current.scrollToIndex({index: 0});
}, 1);
//...

add height to the container should fix the problem
container: {
flex: 1,
paddingTop: 10,
height: 200
},

[majirosstefan]

In my case, (horizontal flatlist on web), I needed to add width for Flatlist component, it worked even without getItemLayout

const ITEM_WIDTH = 550;

const swiperRef = useRef(null);
 const onViewChanged = React.useRef(({ viewableItems }) => {    
    if (viewableItems.length > 0) {
      const { index, item } = viewableItems[0];      
      setActivePhotoIndex(index);
    }
  });

  const viewConfigRef = React.useRef({ viewAreaCoveragePercentThreshold: 100 });

 <FlatList
        showsHorizontalScrollIndicator={false}
        contentContainerStyle={{
          marginHorizontal: 10,
        }}
        **style={{ width: ITEM_WIDTH}}**
        snapToInterval={ITEM_WIDTH}
        decelerationRate={0}
        overScrollMode={"never"}
        snapToAlignment={"center"}
        horizontal
        ref={swiperRef}
        data={data}
        // getItemLayout={(data, index) => { return {length: ITEM_WIDTH, index, offset: ITEM_WIDTH * index} }}
        // onScrollEndDrag={() => console.log('Scroll end')}        
        viewabilityConfig={viewConfigRef.current}
        onViewableItemsChanged={onViewChanged.current}
        renderItem={({ item, index }) => {
          return (
            <View
              style={{
                width: ITEM_WIDTH,                
                alignItems: "center",
              }}
            >

[Sharcoux]

Here, you can see that, without a height set, the scroll is completely broken in the web implementation. The list doesn't shrink to what is actually shown, and other batches of items don't load.

[helloworq]

就我而言，（网络上的水平平面列表），我需要为 Flatlist 组件添加宽度，即使没有 getItemLayout 它也能工作

const ITEM_WIDTH = 550;

const swiperRef = useRef(null);
 const onViewChanged = React.useRef(({ viewableItems }) => {    
    if (viewableItems.length > 0) {
      const { index, item } = viewableItems[0];      
      setActivePhotoIndex(index);
    }
  });

  const viewConfigRef = React.useRef({ viewAreaCoveragePercentThreshold: 100 });

 <FlatList
        showsHorizontalScrollIndicator={false}
        contentContainerStyle={{
          marginHorizontal: 10,
        }}
        **style={{ width: ITEM_WIDTH}}**
        snapToInterval={ITEM_WIDTH}
        decelerationRate={0}
        overScrollMode={"never"}
        snapToAlignment={"center"}
        horizontal
        ref={swiperRef}
        data={data}
        // getItemLayout={(data, index) => { return {length: ITEM_WIDTH, index, offset: ITEM_WIDTH * index} }}
        // onScrollEndDrag={() => console.log('Scroll end')}        
        viewabilityConfig={viewConfigRef.current}
        onViewableItemsChanged={onViewChanged.current}
        renderItem={({ item, index }) => {
          return (
            <View
              style={{
                width: ITEM_WIDTH,                
                alignItems: "center",
              }}
            >

Thank you so much it works for me

[anhphamminh]

A work around I did is to define the function getItemLayout,

Example on expo: https://snack.expo.io/@gusgard/react-native-swiper-flatlist

Code: https://github.com/gusgard/react-native-swiper-flatlist/blob/master/src/components/SwiperFlatList/SwiperFlatList.tsx#L236

getItemLayout={(__data, ItemIndex: number) => ({
      length: Dimensions.get('window').height,
      offset: Dimensions.get('window').height * ItemIndex,
      index: ItemIndex,
 })}

thanks, it works to me

[foxbit19]

Hi, to solve this issue, I've:

• implemented the getItemLayout function using the height of the renderItem as length.
• added height to the container style of the FlatList.

For example, using a renderItem height of 350:

getItemLayout={(data, index) => ({
    length: 350,
    offset: 350 * index,
    index,
})}

In my code, there's no need to use width in the style of the FlatList.

I've used listRef.current?.scrollToIndex({ index }) to update the scroll index and it worked...finally 🥇