React Native的导入导出

1、组件的导入导出方式

问1：如何导出一个组件？

export default class EIComponent extends Component{

  render(){

    return(

      <Text style = {{fontSize:20,backgroundColor:'red'}}>hello.</Text>

    );

  }

}

问2:如何在其他组件中使用导出的组件？

import HelloComponent from './HelloComponent';

2、导出一个或多个变量

问1：如何导出一个或多个变量？

export var name = '小明';

export var age = '22';

// export {name,age};

问2：如何使用导出变量？

import HelloComponent,{name,age} from './HelloComponent';

3、导入导出方法

问1：如何导出方法？

export function sum(a,b){

  return a + b;

}

问2：如何使用导出的方法？

import HelloComponent,{name,age,sum} from './HelloComponent';

实例代码：

　　导出组件、变量、方法

import React, {Component} from 'react';

import {Platform, StyleSheet, Text, View} from 'react-native';

export var name = '小明';

export var age = '22';

// export {name,age};

export default class EIComponent extends Component{

  render(){

    return(

      <Text style = {{fontSize:20,backgroundColor:'red'}}>hello.</Text>

    );

  }

}

export function sum(a,b){

  return a + b;

}

　　使用导出的组件、变量、方法

/**

 * Sample React Native App

 * https://github.com/facebook/react-native

 *

 * @format

 * @flow

 * @lint-ignore-every XPLATJSCOPYRIGHT1

 */

import React, {Component} from 'react';

import {Platform, StyleSheet, Text, View} from 'react-native';

import HelloComponent,{name,age,sum} from './HelloComponent';

const instructions = Platform.select({

  ios: 'Press Cmd+R to reload,\n' + 'Cmd+D or shake for dev menu',

  android:

    'Double tap R on your keyboard to reload,\n' +

    'Shake or press menu button for dev menu',

});

type Props = {};

export default class App extends Component<Props> {

  constructor(props){

    super(props);

    this.state =({

      result:''

    })

  }

  render() {

    return (

      <View style={styles.container}>

        <Text style ={styles.welcome}>名字:{name}</Text>

        <Text style ={styles.welcome}>年龄:{age}</Text>

        <Text style ={styles.welcome}

              onPress={()=>{

                var result = sum(2,3);

                this.setState({

                    result:result

                })

              }}

        >2+3={this.state.result}</Text>

      </View>

    );

  }

}

const styles = StyleSheet.create({

  container: {

    flex: 1,

    justifyContent: 'center',

    alignItems: 'center',

    backgroundColor: 'white',

  },

  welcome: {

    fontSize: 20,

    textAlign: 'center',

    margin: 10,

  },

  instructions: {

    textAlign: 'center',

    color: '#333333',

    marginBottom: 5,

  },

});

巴特西

React Native的导入导出

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