Question

如何通过ref访问react-native listview子组件？

class MyComponent extends Component {
  constructor() {
    super();
    const ds = new ListView.DataSource({rowHasChanged: (r1, r2) => r1 !== r2});
    this.state = {
      dataSource: ds.cloneWithRows(['row 1', 'row 2', 'row 3', 'row 4', 'row 5', 'row 6']),
    };
  }

  onTap() {
    console.log(this.refs)
    /* After getting touchComponent refs below block of code has to be executed.
    that.refs.touchComponent.measure((ox, oy, width, height, px, py) => {
    this.setState({
       isVisible: true,
       buttonRect: {x: px, y: py, width: width, height: height}
    });
  });
  */
 }

  render() {
    return (
      <ListView ref="listView"
        dataSource={this.state.dataSource}
        renderRow={(rowData) => <TouchableHighlight ref="touchComponent" onPress={this.onTap.bind(this)}><Text>{rowData}</Text></TouchableHighlight>}
      />
    );
  }
}

console.log(this.refs) 打印 Object {listView: Object}

如何访问TouchableHighlight组件参考？

我经历了React Native: Refs in ListView和React Native - get refs of custom components in listview from renderRow，但我不明白他们是怎么做的。

Answer 1

您无法通过在ListView中添加引用的字符串方式访问引用，您必须使用回调技术来应用引用

var express = require('express');
var app = express();
var server = require('http').createServer(app);
var io = require('socket.io')(server);
var fs = require('fs');

app.use(express.static(__dirname + '/public'));

app.get('/galerie', function(req, res) {
    res.sendFile(__dirname + '/galerie.html');
});

app.get('/', function(req, res) {
    res.sendFile(__dirname + '/index.html');
});
//var io = require('socket.io').listen(http);

io.sockets.on('connection', function (socket, pseudo) {
...
});
server.listen(8080);

但很可能即使在获得参考后你也无法访问测量方法。要获取pageX和pageY，您可以使用onPress传递touch事件并使用nativeEvent来获取pageX和pageY，您可以使用measureInWindow方法获取宽度和高度： -

 <ListView ref="listView"
        dataSource={this.state.dataSource}
        renderRow={(rowData) => <TouchableHighlight ref={(TouchableHighLight) => { this.button = TouchableHighLight; }} onPress={this.onTap.bind(this)}><Text>{rowData}</Text></TouchableHighlight>}
      />

方法定义可能是这样的： -

onPress={(event) => this.onTap(event)}

Answer 2

你可以尝试这样的东西来访问被点击的元素：

import React, { Component } from 'react'
import {
  Text,
  ListView,
  TouchableHighlight,
  View,
} from 'react-native';

export default class App extends Component {
  constructor() {
    super();
    this.buildList = this.buildList.bind(this)
    this.onTap = this.onTap.bind(this)

    const ds = new ListView.DataSource({rowHasChanged: (r1, r2) => r1 !== r2});
    this.rows = []
    this.state = {
      dataSource: ds.cloneWithRows([
        {id: 0, text: 'row 1'},
        {id: 1, text: 'row 2'},
        {id: 2, text: 'row 3'},
        {id: 3, text: 'row 4'},
        {id: 4, text: 'row 5'},
        {id: 5, text: 'row 6'}

      ]),
    };
  }

  onTap(id) {
    console.log(this.rows[id])
 }

  buildList (data) {
    const onRowTap = () => this.onTap(data.id)
    return (
      <TouchableHighlight key={data.id} ref={row => this.rows[data.id] = row} onPress={onRowTap}>
          <Text style={{color: '#000', padding: 20}}>{data.text}</Text>
      </TouchableHighlight>
    )
  }

  render() {
    return (
      <View>
        <ListView style={{marginTop: 50}} ref="listView"
          dataSource={this.state.dataSource}
          renderRow={this.buildList}
        />
      </View>
    );
  }
}

与您发布的链接具有相同的概念，但这种方式可能更容易理解。您不是尝试从类refs获取行，而是在类范围中创建一个空数组，并在构建列表时用行填充它。然后你只需将一个id传递给按下功能，你就可以得到你的行。他们以同样的方式深入listView引用，因为实际上行是ListeView个孩子，所以你要引用ListView引用，而不是你的Class引用

如何通过ref访问react-native listview子组件？

2 个答案: