Question

我已经在我的列表中添加了onEndReached，它可以正常工作。现在，如果我完成了要提取的项目，就必须停止它。如果我在没有足够的元素获取时调用该函数，则会出现错误：“未定义不是对象（正在评估item.title.rendered）”

这是我的单位列表：

<FlatList
          ItemSeparatorComponent={this.FlatListItemSeparator}
          data={this.state.dataSource}
          renderItem={({ item }) => (
            //on touch --> open article (call _onTextPress)
            <TouchableWithoutFeedback onPress={this._onTextPress.bind(this, item.id)}>
              <View style={{flexDirection:'row', justifyContent: 'space-between'}}>
                <View style={styles.titoletti}>
                  <HTML html={'<p style="color:#fd3a18; font-size:17px;"><strong>'+item.title.rendered.substring(0,70)+'...</strong></p>\n'}/>
                  <Text style={styles.date}>{item.date.substring(0, 10)}</Text>
                </View>
                <View style={{flexDirection:'column', justifyContent:'space-between'}}>
                  <View></View>
                  <Icon
                    name="ios-arrow-forward"
                    style={styles.rightIcon}/>
                  <View></View>
                </View>
              </View>
            </TouchableWithoutFeedback>
          )}
          keyExtractor={({ id }, index) => String(id)}
          onEndReached={this.handleLoadMore}
          onEndReachedThreshold ={0.01}
          ListFooterComponent={this.renderFooter}
        />

这是onEndReachde调用的函数：

  handleLoadMore = () => {
    this.setState({
      page: this.state.page +1 },
      this.getData
    )
  }

componentDidMount() {
    this.getData();
  }

  getData = async() => {
    const { navigation } = this.props;
    const id = String(navigation.getParam('id'));
    this.setState({
      title: String(navigation.getParam('title')),
      isLoading: true,
    })

    return fetch('https://www.rallyssimo.it/wp-json/wp/v2/posts?per_page=10&categories='+id+'&page='+this.state.page)
      .then(response => response.json())
      .then(responseJson => {
        this.setState(
          {
            dataSource: this.state.dataSource.concat(responseJson),
            isLoading: false,

          },console.log(this.state.dataSource.lenght),
          function() {}
        );
      })
      .catch(error => {
        console.error(error);
      });
  }

项目完成后如何锁定onEndReached？

0 个答案: