react native 学习之模仿”探探“实现豆瓣电影app部分功能

Z时代
2024-01-10
分类：综合

react

一、首先配置环境当然是node 下用npm

npm install -g react-native-cli

然后创建项目

react-native init react1 cd react1 react-native run-android 新开一个cmd 启动项目

react-native start

在电脑上启动的安卓虚拟机不能摇一摇，所以还需要在 cmd 里输入

adb shell input keyevent 82 或者

adb -s emulator-5554 shell input keyevent 82

在笔记本下启动的虚拟机会比较卡可以设置如下，会稍微好点

二、需要实现的界面和功能如下

新建一个AppNavigator.js 文件用于首页和详情页的跳转

'use strict'
import React, { Component } from 'react';
import { StyleSheet, Navigator } from 'react-native';
import ViewContainer from '../views/indexView';
import DetailContainer from '../views/Detail';
class AppNavigator extends Component {
    _renderScene(route, navigator) {
        let globalNavigatorProps = { navigator };
        switch(route.ident){
          case 'indexView':
            return(
              <ViewContainer {...globalNavigatorProps} />
            )
          case 'detail':
            return(
              <DetailContainer {...globalNavigatorProps}  />
            )
          default:
            return(
              <ViewContainer {...globalNavigatorProps} />
            )
        }
    }
    render() {
        return (
            <Navigator initialRoute={this.props.initialRoute}
              ref="AppNavigator"
              renderScene={this._renderScene}/>
        );
    }
}module.exports = AppNavigator;

index.android.js 首先展示首页

'use strict'
import React, { Component } from 'react';
import { AppRegistry, StatusBar } from 'react-native';
import AppNavigator from './app/common/AppNavigator';
class react1 extends Component {
  render() {
    this._setStatusBar();
    return (
        <AppNavigator 
          initialRoute={{ident: 'indexView'}}/>
    );
  }
//状态栏的颜色
  _setStatusBar() {
    StatusBar.setBackgroundColor('#af3329', true);
  }
}AppRegistry.registerComponent('react1', () => react1);

reactjs 写样式和传统的css 有一定的区别，驼峰和没有简写如(margin: 0 auto) 是没有的，同时安卓机下是不能显示出阴影的

首页中的卡片布局如下

'use strict'
import React, { Component } from 'react';
import { StyleSheet, Text, View, AsyncStorage, Image } from 'react-native';
import util from '../common/util';
class Card extends Component {
    constructor(props) {
        super(props);
    }
    render() {
        let subject, posterImage, image; // 大图
        this.props.subject ? subject = this.props.subject : subject = this.props;
        posterImage = subject.images.large;
        if(posterImage != '' && posterImage != null) {
            image = <Image resizeMode="stretch" style={styles.posterImage}
                        source={{uri: posterImage}}/>;
        }else{
            image = <Text>{this.props.subject.title}</Text>;
        }
        return (
            <View style={[styles.cardBox, this.props.CardPosition ? {
                position: 'absolute',
                top: this.props.CardTop} : null
            ]}>
                <View style={styles.posterWrap}>
                    {image}
                    {this.props.new ?  <Text style={styles.newTop}>新上榜</Text> : null }
                    {this.props.rank ? <Text style={styles.topNumber}>Top {this.props.rank}</Text> : null}
                </View>
                <View style={styles.cinemaMsg}>
                    <View style={styles.cinemaMsgItem}>
                        <Text style={styles.title} numberOfLines={1} >{subject.title} 
                            { this.props.box ? <Text style={styles.cast}> {subject.casts[0].name}...</Text> : null}
                        </Text>
                        <Text style={styles.average}>评分:{subject.rating.average}</Text>
                    </View>
                    <View style={styles.cinemaMsgItem}>
                        <Text style={[styles.arrivedMsg, styles.flex2]} numberOfLines={1}>{subject.original_title} ({subject.year})</Text>
                        <Text style={styles.boxOffice} numberOfLines={1}>{ this.props.box ?  '票房：' + this.props.box/1000 :  subject.casts[0].name}</Text> 
                    </View>
                    <View style={styles.cinemaMsgItem}>
                        <Text style={styles.arrivedMsg}>类型:{subject.genres.join('\/')}</Text>
                        <Text style={styles.directors}>导演:{subject.directors[0].name}</Text>
                    </View>
                </View>
            </View>
        );
    }
}
const styles = StyleSheet.create({
    flex2: {
        overflow: 'hidden',
    },
    cardBox: {
        borderRadius: 5,
        borderWidth: 2,
        marginTop: 2,
        width: 310,
        marginHorizontal: (util.size.width - 310) / 2 ,
        borderColor: '#e1e2da',
        backgroundColor: '#ffffff',
    },
    posterWrap: {
        width: 310,
        borderColor: '#e1e2da',
    },
    posterImage: {
        height: 340,
        width: 310,
    },
    newTop: {
        position: 'absolute',
        top: 0,
        right: 0,
        fontSize: 12,
        color: '#ffffff',
        backgroundColor: 'rgba(230,69,51,0.65)',
        paddingVertical: 1,
        paddingHorizontal: 3,
    },
    topNumber: {
        position: 'absolute',
        top: 0,
        left: 0,
        fontSize: 12,
        color: '#ffffff',
        paddingVertical: 1,
        paddingHorizontal: 3,
        backgroundColor: 'rgba(255,164,51,0.7)',
    },
    cinemaMsg: {
        width: 300,
        padding: 2,
        flexDirection: 'column',
    },
    cinemaMsgItem: {
        flex: 1,
        justifyContent: 'space-between',
        flexDirection: 'row',
    },
    title: {
        flex: 2,
        fontSize: 15,
        color: '#1d1d1d',
        textAlign: 'left',
    },
    cast: {
        fontSize: 12,
    },
    average: {
        flex: 1,
        fontSize: 15,
        color: '#e64533',
        textAlign: 'right',
    },
    arrivedMsg: {
        fontSize: 13,
        textAlign: 'left',
    },
    boxOffice: {
        flex:1,
        fontSize: 12,
        color: '#e64533',
        textAlign: 'right',
    },
    directors: {
        fontSize: 12,
        textAlign: 'right',
        color: '#1d1d1d',
    },
});module.exports = Card;

卡片滑动swipe 效果

npm install -g react-native-swipe-cards

import SwipeCards from 'react-native-swipe-cards';
render() {
        let data = (this.props.dataCinema ? JSON.parse(this.props.dataCinema) : null);
        return (
                <View style={styles.box}>
                    { data ? 
                        <SwipeCards cards={data} style={styles.swipeCards}
                            loop={true}
                            renderCard={(cardData) => <Card {...cardData} />}
                            handleYup={this.handleYup}  renderNope={this.renderNope} renderYup={this.renderYup}
                            handleNope={this.handleNope} 
                            cardRemoved={this.cardRemoved}/>
                        : null
                    }
                </View>
        );
    }

首页抽屉效果

npm install -g react-native-drawer

    render() {
        return (
            <Drawer
                ref={(ref) => this._drawer = ref}
                type="static"
                content={
                  <LeftControlPanel closeDrawer={this.closeDrawer}/>
                }
                styles={{main: {shadowColor: '#000000', shadowOpacity: 0.3, shadowRadius: 15}}}
                captureGestures={true}
                acceptTap={true}
                acceptPan={true}
                negotiatePan={false}
                useInteractionManager={false}
                tweenDuration={100}
                panThreshold={0.08}
                panOpenMask={0.03}
                panCloseMask={0}
                disabled={this.state.drawerDisabled}
                openDrawerOffset={(viewport) => {
                    return 80
                }}
                panOpenMaskY={50}
                side="left"
                tweenHandler={Drawer.tweenPresets.parallax}
            >
                <Drawer
                    type="static"
                    ref={(ref) => this._drawer2 = ref}
                    content={
                        <RightControlPanel closeDrawer={this.closeDrawer2} />
                    }
                    captureGestures={true}
                    acceptTap={true}
                    acceptPan={true}
                    negotiatePan={false}
                    useInteractionManager={false}
                    tweenDuration={100}
                    panThreshold={0.08}
                    panOpenMask={0.03}
                    panCloseMask={0}
                    openDrawerOffset={(viewport) => {
                        return 80
                    }}
                    side="right"
                    tweenHandler={Drawer.tweenPresets.parallax}
                  >
                    <Main  topItem={this.state.topItem} navigator={this.props.navigator}/>
                </Drawer>            </Drawer>

以上所用插件我都有改动符合demo的需求····

通过这次的demo学习对react 有进一步的认识与体会，

组件的生命周期

componentWillReceiveProps(nextProps){} 接收新的数据

shouldComponentUpdate(nextProps, nextState){ return boo} 必须有返回值，返回 false componentWillUpdate()不会被调用 render()也再不执行，这样根据需要可以禁止页面的更新。

react native事件捕获

onStartShouldSetPanResponderCapture， onMoveShouldSetPanResponderCapture连个方法都有返回值，返回true 时，事件就不再传递，被当前组件劫持并调用当前组件的onResponderStart或者onResponderRlase等

数据请求利用 facth 比传统ajax 更简洁当然属于es6 的

fetch(url).then((response) => response.text())
        .then((responseText) => {
            successCallback(JSON.parse(responseText));
        }).catch(function(err){
            failCallback(err);        });

state 更新用setState 当然也可以用如

 this.state['cards'] = JSON.parse(nextProps.dataCinema);   this.forceUpdate();

forceUpdate就是重新render。有变量不在state上，缺又想更新state，刷新render；或者state里的某个变量层次太深，更新的时候没有自动触发render。这些时候都可以手动调用forceUpdate自动触发render。

跳转到github

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