FlatList的点击Demo

import React, { Component, PureComponent } from 'react';import {  View,  TouchableOpacity,  FlatList,  Text,  Alert,} from 'react-native';import styles from './style';import commonStyle from '../../Common/Style'; const data = [  {id: 'T&C', index: 0,},  {id: 'Privacy', index: 1,},  {id: 'FAQs', index: 2,},  {id: 'Feedback', index: 3,},  {id: 'Wooloomooloo', index:4},];class MyListItem extends React.PureComponent {  _onPress = () => {    // MyList的onPressItem    this.props.onPressItem(this.props.id);  };   render() {    return (  <View style = {styles.view_Item}>                  <TouchableOpacity      onPress={() => this._onPress()}>                   <Text style = {styles.item}> {this.props.title} </Text>       </TouchableOpacity>                  </View>    )  }}class MyList extends React.PureComponent {  state = {selected: (new Map(): Map<string, boolean>)};  _keyExtractor = (item, index) => item.id;  _onPressItem = (id: string) => {    // updater functions are preferred for transactional updates    this.setState((state) => {      // copy the map rather than modifying state.      const selected = new Map(state.selected);      selected.set(id, !selected.get(id)); // toggle      return {selected};    });    //渲染时候的onPressItem    this.props.onPressItem(id)  };   _renderItem = ({item}) => (    <MyListItem      id={item.id}      onPressItem={this._onPressItem}      selected={!!this.state.selected.get(item.id)}      title={item.id}    />  );  render() {    return (      <FlatList        data={this.props.data}        extraData={this.state}        keyExtractor={this._keyExtractor}        renderItem={this._renderItem}        onPress = {this._onPressItem}      />    );  }}export default class index extends Component<{}> {  constructor(props) {    super(props);      this.state = {};    this.onPressItem = this.onPressItem.bind(this)  }    static navigationOptions = {          //导航栏标题            title:'关于',           drawerLabel: '关于',      };    onPressItem(message) {    Alert.alert("点击了" + message.toString())  }  render() {    return (        <View style = {commonStyle.safeView}>          <View style ={ styles.main}>              <MyList               data = {data}              onPressItem = {this.onPressItem.bind(this)}              />          </View>        </View>      );  }}