javascript – 在React Native中的组件之间进行通信(子级 – >父级)

我需要在文件artistPage.js中引用index.avia中的TabNavigator.特别是,当用户在页面artistPage上时,我需要更改样式以隐藏TabBar.

我怎样才能做到这一点？有任何想法吗？

我尝试在道具中传递样式但是有只读模式(

index.ios.js

'use strict'

import React, { Component } from 'react';
import {
  AppRegistry,
  StyleSheet,
  View,
  Image,
  Text,
  NavigatorIOS,
  TouchableHighlight,
  NavigationBar,
} from 'react-native';
import config from './config';

import ImagesList from './app/imagesList';
import TabNavigator from 'react-native-tab-navigator';
import Badge from './node_modules/react-native-tab-navigator/Badge'

class MyApp extends Component {
  constructor(props) {
    super(props);

    this.state = {
      selectedTab: 'images',
      showTabBar: true
    };
  }

  render() {
    let tabBarStyle = {};
    let scenestyle = {};
    if (this.state.showTabBar) {
      tabBarStyle = styles.tabBar;
      scenestyle.paddingBottom = 54;
    } else {
      tabBarStyle.height = 0;
      tabBarStyle.overflow = 'hidden';
      scenestyle.paddingBottom = 0;
    }
    return (
      <View style={styles.container}>
        <TabNavigator 
          tabBarStyle={ tabBarStyle } 
          scenestyle={scenestyle} 
          >
          <TabNavigator.Item
            titleStyle={styles.title}
            selectedTitleStyle={styles.title_select}
            selected={this.state.selectedTab === 'images'}
            title="TATTOOS"
            renderIcon={() => <Image source={require('./images/tabbar/tattoos_icon.png')} />}
            renderSelectedIcon={() => <Image source={require('./images/tabbar/tattoos_icon_selected.png')} />}
            onPress={() => this.setState({ selectedTab: 'images' })}>
            <NavigatorIOS
              style={styles.container}
              initialRoute={{
                title: 'MyApp',
                component: ImagesList,
                passprops: { showTabBar: true},
              }}
              navigationBarHidden={true}/>
          </TabNavigator.Item>

        </TabNavigator>
      </View>
    );

  }
}

AppRegistry.registerComponent('MyApp', () => MyApp);

imageList.js

'use strict'

import React, { Component } from 'react';
import {
  StyleSheet,
  ListView,
  View,
  Text,
  Image,
  Dimensions,
  ActivityIndicator,
  TouchableHighlight,
  RefreshControl
} from 'react-native';

import ArtistPage from './imageCard';

class ImagesList extends Component {
  constructor(props) {
    super(props);

    this.state = {
    };
  }

  _artistPage() {
    this.props.navigator.push({
        component: ArtistPage
      });
  }

  render() {
      return (
        <View style={styles.container}>
          <TouchableHighlight
            onPress={this._artistPage()}
            >
            <Text>Got to Next Page</Text>
          </TouchableHighlight>
        </View>
      );
    }
  }
}

module.exports = ImagesList;

artistPage.js

'use strict'

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

class ArtistPage extends Component {
  constructor(props) {
    super(props);

    this.state = {

    };
  }

  _backTo() {
    this.props.navigator.pop();
  }

  render() {
    return (
      <View>
        <TouchableHighlight style={{marginTop: 100, marginLeft: 50}} onPress={() => this._backTo()} >
          <Text>Back {this.props.showTabBar.toString()}</Text>
        </TouchableHighlight>
      </View>
    );
  }
}


module.exports = ArtistPage;

以下是隐藏TabNavigator：https://github.com/exponentjs/react-native-tab-navigator的方法

let tabBarHeight = 0;
<TabNavigator
  tabBarStyle={{ height: tabBarHeight, overflow: 'hidden' }}
  scenestyle={{ paddingBottom: tabBarHeight }}
/>

但我不明白如何从artistPage.js访问它

谢谢！

解决方法:

React中的数据流是一种方式.在实践中它意味着,为了改变某个组件通过道具接收的东西,它需要通过道具的函数回调到父组件.

React网站的概念是a nice intro.

在您的特定情况下,您可以在MyApp中具有tabBarVisible状态,并在内部渲染中计算要应用于选项卡栏的样式.

MyApp也可以有一个方法来改变这种状态：

hideTabBar() {
  this.setState({ tabBarVisible: true });
}

现在,为了让ArtistPage切换,你可以将hideTabBar函数从MyApp传递给ArtistPage作为道具,并在lifecycle hook中的ArtistPage中调用它,就像componentDidMount一样.