React-Native子组件修改父组件的几种方式,兄弟组件状态修改(转载)

子组件修改父组件的状态,在开发中非常常见,下面列举了几种方式。
DeviceEventEmitter可以跨组件,跨页面进行数据传递,还有一些状态的修改。http://www.jianshu.com/p/c6991a241b4f

兄弟组件可以进行修改,所谓兄弟组件,就是说同一个页面,有两个组件,组件A,组件B,组件A的状态的变化,可以导致组件B的状态变化,有两种方式。第一种,使用DeviceEventEmitter跨组件通信。第二种,在页面内定义一个State,组件A,使用props属性引入,操作组件A,修改页面内的State,然后,组件B,也是引入页面内的State,所有,当组件A状态变化时,修改页面的State,重新Render,然后,更新组件B,组件B进行Render。

二: Coding
新建三个组件:分别为PostCallMsgAndMsg,PostCallMsg,PostMsg;
在Msg进行使用。

import React, { Component } from 'react';
import {
    AppRegistry,
    StyleSheet,
    Text,
    View,
    DeviceEventEmitter
} from 'react-native';
import PostMsg from './PostMsg'
import PostCallMsg from './PostCallMsg'
import PostCallMsgAndMsg from './PostCallMsgAndMsg'

export default class Msg extends Component {
    constructor(props){
        super(props);
        this.state={
            listenerMsg:'listenerMsg',
            callMsg:'callMsg',
            callMsgAndMsg:'callMsgAndMsg'

        }
    }


    componentDidMount() {
        //注意addListener的key和emit的key保持一致
        this.msgListener = DeviceEventEmitter.addListener('Msg',(listenerMsg) => {
            this.setState({
                listenerMsg:listenerMsg,
            })
        });

    }

    componentWillUnmount() {
        //此生命周期内,去掉监听
        this.msgListener&&this.msgListener.remove();
    }



    render() {
        return (
            <View style={styles.container}>
                    <Text>第一种方式  DeviceEventEmitter:</Text>
                    <Text>{this.state.listenerMsg}</Text>
                    <PostMsg  />

                    <Text>第二种方式  CallBack:</Text>
                    <Text>{this.state.callMsg}</Text>
                    <PostCallMsg  onChangeMsg={
                        this.onMsgByCall
                    }/>

                    <Text>第三种方式  CallBack有参数:</Text>
                    <Text>{this.state.callMsgAndMsg}</Text>
                    <PostCallMsgAndMsg  onChangeMsg={(msg)=>{
                        this.onMsgByCallAndMsg(msg)
                    } }/>

            </View>
        );
    }

    onMsgByCall=()=>{
        this.setState({
            callMsg:'通过CallBack修改父组件状态值'
        })
    }


    onMsgByCallAndMsg=(msg)=>{
        this.setState({
            callMsgAndMsg:msg
        })
    }
}

const styles = StyleSheet.create({
    container: {
        flex: 1,
        justifyContent: 'center',
        alignItems:'center',
    },
});
import React, { Component } from 'react';
import {
    AppRegistry,
    StyleSheet,
    Text,
    View,
    TouchableOpacity,
} from 'react-native';

export default class PostCallMsgAndMsg extends Component {
    render() {
        return (
            <View style={styles.container}>
                <View style={styles.viewLine}/>
                <TouchableOpacity onPress={this._postMsgByCallBack}>
                    <Text>PostCallMsgAndMsg</Text>
                </TouchableOpacity>
            </View>
        );
    }


    _postMsgByCallBack=()=>{
        if(this.props.onChangeMsg){
            this.props.onChangeMsg('通过PostCallMsgAndMsg来传递属性');
        }
    }
}

const styles = StyleSheet.create({
    container: {
        justifyContent: 'center',
        alignItems: 'center',
        marginBottom:20,
    },
});
import React, { Component } from 'react';
import {
    AppRegistry,
    StyleSheet,
    Text,
    View,
    TouchableOpacity,
} from 'react-native';

export default class PostCallMsg extends Component {
    render() {
        return (
            <View style={styles.container}>
                <View style={styles.viewLine}/>
                <TouchableOpacity onPress={this._postMsgByCallBack}>
                    <Text>Callback</Text>
                </TouchableOpacity>
            </View>
        );
    }


    _postMsgByCallBack=()=>{
        if(this.props.onChangeMsg){
            this.props.onChangeMsg();
        }
    }
}

const styles = StyleSheet.create({
    container: {
        justifyContent: 'center',
        alignItems: 'center',
        marginBottom:20,
    },

});
import React, { Component } from 'react';
import {
    AppRegistry,
    StyleSheet,
    Text,
    View,
    TouchableOpacity,
    DeviceEventEmitter,
} from 'react-native';

export default class PostMsg extends Component {
    render() {
        return (
            <View style={styles.container}>
                <TouchableOpacity onPress={this._postMsgByListener}>
                    <Text>DeviceEventEmitter</Text>
                </TouchableOpacity>
            </View>
        );
    }

    _postMsgByListener=()=>{
        DeviceEventEmitter.emit('Msg','此消息来自于子组件,DeviceEventEmitter父组件进行修改和状态变化');
    }

}

const styles = StyleSheet.create({
    container: {
        justifyContent: 'center',
        alignItems: 'center',
        marginBottom:20,
    },
});
原文地址:https://www.cnblogs.com/qiyecao/p/8323749.html