在React Native中过滤ListView数据

Question

I am trying to write a fliter for my List View in react native. But It is not working , and I don't know why. Here is my Class -

 import { AppRegistry, Image, ListView, StyleSheet, Text, TextInput, Navigator, TouchableHighlight, TouchableOpacity, filter, View } from 'react-native'; var REQUEST_URL = GLOBAL.STATES_URL + '?apikey=' + GLOBAL.API_KEY; class MainPage extends Component { constructor(props) { super(props); this.state = { dataSource: new ListView.DataSource({ rowHasChanged: (row1, row2) => row1 !== row2, }), loaded: false, searchText: '', state: '', }; } componentDidMount() { this.fetchData(); } componentDidUpdate() { if (this.state.searchText === '') { this.fetchData(); } } filterStates(searchText, states) { var text = searchText.toLowerCase(); var rows = []; for (var i=0; i < states.length; i++) { var stateName = states[i].name.toLowerCase(); if(stateName.search(text) !== -1){ rows.push({ name : states[i].name, }); } } this.setState({ dataSource: this.state.dataSource.cloneWithRows(rows), loaded : true, }); } fetchData() { fetch(REQUEST_URL) .then((response) => response.json()) .then((responseData) => { this.setState({ dataSource: this.state.dataSource.cloneWithRows(responseData), loaded: true, }); }) .done(); } setSearchText(event){ var searchText = event.nativeEvent.text; this.setState({searchText}); fetch(REQUEST_URL) .then((data) => { this.filterStates(searchText, data); }) .done(); } render() { return ( <Navigator renderScene={this.renderScene.bind(this)} navigator={this.props.navigator} navigationBar={ <Navigator.NavigationBar style={{backgroundColor: '#246dd5'}} routeMapper={NavigationBarRouteMapper} /> } /> ); } renderScene(route, navigator) { if (!this.state.loaded) { return this.renderLoadingView(); } return ( <View style={styles.combo}> <TextInput style={styles.searchBar} value={this.state.searchText} onChange={this.setSearchText.bind(this)} placeholder='Search' /> <ListView dataSource={this.state.dataSource} renderRow={this.renderState.bind(this)} // renderScrollComponent={props => <RecyclerViewBackedScrollView {...props} />} renderSeparator={(sectionID, rowID) => <View key={`${sectionID}-${rowID}`} style={styles.separator} />} style={styles.listView} /> </View> ); } renderLoadingView() { return ( <View style={styles.container}> <Text> Loading States... </Text> </View> ); } renderState(state,route,navigator) { return ( <TouchableHighlight onPress={this.gotoPersonPage.bind(this,state)}> <View style={styles.row}> <View style={styles.container}> <Text style={styles.name}>{state.name}</Text> </View> </View> </TouchableHighlight> ); } gotoPersonPage(state) { this.props.navigator.push({ id: 'PersonPage', name: 'PersonPage', data: {name:state.name , abbreviation:state.abbreviation}, }); } } 

Can Anybody please tell that what is the issue in the above code, and solution for that issue. Thanks in advance.

Answer 1

Try setting up the new ListView.DataSource({ rowHasChanged: (row1, row2) => row1 !== row2 outside of the component:

var ds = new ListView.DataSource({ rowHasChanged: (row1, row2) => row1 !== row2    

class MainPage extends Component {
  this.state = {
    dataSource: new ListView.DataSource({
      rowHasChanged: (row1, row2) => row1 !== row2,
    }),
    loaded: false,
    searchText: '',
    state: '',
  };
}

Then setting the state like this:

filterStates(searchText, states) {
    ...

    this.setState({
       dataSource: ds.cloneWithRows(rows),
       loaded : true,
     });
  }

and this:

fetchData() {
    fetch(REQUEST_URL)
      .then((response) => response.json())
      .then((responseData) => {
        this.setState({
          dataSource: ds.cloneWithRows(responseData),
          loaded: true,
        });
      })
      .done();
}