如何解决FlatList React native中的Key问题

Question

这是我第一次使用 React，我的程序中有这个问题。 请你帮帮我好吗？ 我在我的应用程序中使用 TMDB API。

index.js:1 Warning: Encountered two children with the same key, `.$106242`. Keys should be unique so that components maintain their identity across updates. Non-unique keys may cause children to be duplicated and/or omitted — the behavior is unsupported and could change in a future version.
        in div (created by View)
        in View (created by ScrollView)
        in div (created by View)
        in View (created by ForwardRef)
        in ForwardRef (created by ScrollView)
        in ScrollView (created by VirtualizedList)
        in VirtualizedList (created by FlatList)
        in FlatList (at Search.js:71)
        in div (created by View)
        in View (at Search.js:65)
        in Search (at App.js:8)
        in App (created by ExpoRootComponent)
        in ExpoRootComponent (created by RootComponent)
        in RootComponent
        in div (created by View)
        in View (created by AppContainer)
        in div (created by View)
        in View (created by AppContainer)
        in AppContainer

<FlatList
  data={this.state.films}
  keyExtractor={(item, index) => item.id.toString()}
  renderItem={({ item }) => <Text> <FilmItem film={item} /> </Text>}
  onEndReachedThreshold={0.5}
  onEndReachedThreshold={0.5}
  onEndReached={() => {
    if (this.page < this.totalPages) { // On vérifie qu'on n'a pas atteint la fin de la pagination (totalPages) avant de charger plus d'éléments
      this._loadFilms()
    }
  }}
/>

任何提议

Answer 1

将您的平面列表代码更改为此，

<FlatList
    data = {this.state.films}
    keyExtractor = {(item, index) => index+"_"+item.id.toString() }
    renderItem={({item}) => <Text> <FilmItem film={item} /> </Text>}
    onEndReachedThreshold={0.5}
    onEndReachedThreshold={0.5}
    onEndReached={() => {
        if (this.page < this.totalPages) { // On vérifie qu'on n'a pas atteint la fin de la pagination (totalPages) avant de charger plus d'éléments
            this._loadFilms()
        }
    }}
/>

Answer 2

您可以为 keyExtractor 使用索引或索引与电影的任何属性的组合。 在下面的示例中，我使用了索引并在同一行添加了注释，它也可以用来代替索引。

<FlatList
    data = {this.state.films}
    keyExtractor = {(item, index) => index } // `${item.id.toString()}-${index}`
    renderItem={({item}) => <Text> <FilmItem film={item} /> </Text>}
    onEndReachedThreshold={0.5}
    onEndReachedThreshold={0.5}
    onEndReached={() => {
        if (this.page < this.totalPages) { // On vérifie qu'on n'a pas atteint la fin de la pagination (totalPages) avant de charger plus d'éléments
            this._loadFilms()
        }
    }}
/>