React Native 添加 Redux 支持
0x1 前言
之前写的项目都是人家编写好的脚手架，里面包含项目所需的环境文件，但由于有些东西用不到打包增加软件体积，所以自己从头搭建个环境。是基于 Native Base + react-navigation + Redux 的 react Native 脚手架，现在项目环境如下：
{
"name": "app",
"version": "0.0.1",
"private": true,
"scripts": {
"start": "react-native start",
"test": "jest",
"lint": "eslint ."
},
"dependencies": {
"native-base": "^2.13.4",
"react": "16.8.6",
"react-native": "0.60.5",
"react-native-gesture-handler": "^1.3.0",
"react-native-keyboard-aware-scroll-view": "^0.9.1",
"react-native-reanimated": "^1.2.0",
"react-navigation": "^3.11.1"
},
"devDependencies": {
"@babel/core": "^7.5.5",
"@babel/runtime": "^7.5.5",
"@react-native-community/eslint-config": "^0.0.5",
"babel-eslint": "7.2.3",
"babel-jest": "^24.8.0",
"eslint": "4.4.1",
"eslint-plugin-flowtype": "2.35.0",
"eslint-plugin-import": "2.7.0",
"eslint-plugin-jsx-a11y": "6.0.2",
"eslint-plugin-prettier": "2.1.2",
"eslint-plugin-react": "7.1.0",
"eslint-plugin-react-native": "3.0.1",
"jest": "^24.8.0",
"metro-react-native-babel-preset": "^0.56.0",
"prettier": "1.5.3",
"react-test-renderer": "16.8.6"
},
"jest": {
"preset": "react-native"
}
}资源搜索网站大全 https://www.renrenfan.com.cn 广州VI设计公司https://www.houdianzi.com
0x2 添加 Redux 支持
这里大概讲解下安装类库支持：
yarn add yarn add react-navigation react-native-gesture-handler react-native-reanimated native-base链接字体库资源：
react-native linkreact-navigation 在 Android 环境额外添加代码支持，具体情况文档： MainActivity.java
react-navigation 在 react-native 版本大于 0.60 的时候不需要执行 react-native link 链接。
由于项目需要状态管理支持，故添加 Redux 状态管理类库支持，在 React Native 环境下和 React 项目一样：
yarn add redux react-redux redux-loggerredux-logger 是监控状态数据流日志，可以在控制台输出状态值的信息。
由于项目基本环境是 Native Base 环境，这里怎么安装它就不再描述了，故在基础项目下添加项目支持 Redux 即可。打开 ./src/App.js 添加 Redux 能力支持：
import {Root} from "native-base";
import {createStackNavigator, createAppContainer} from "react-navigation";
import {applyMiddleware, createStore} from "redux";
import {Provider} from "react-redux";
import React from "react";
import logger from "redux-logger";
import allReducers from "./store";
import reduxDemo from "./screens/reduxDemo";
const store = createStore(
allReducers,
applyMiddleware(logger)
); // 创建 Store
const AppNavigator = createStackNavigator(
{
ReduxDemo: {screen: reduxDemo},
},
{
initialRouteName: "ReduxDemo", // 路由入口
headerMode: "none", // 由于 react-navigation 默认导航栏自定义效果很差，故隐藏
},
);
const AppContainer = createAppContainer(AppNavigator);
export default () => (
<Provider store={store}>
<Root>
<AppContainer/>
</Root>
</Provider>
);创建状态触发事件业务集 ./store/reducers/counter.js ：
let count = 0;
export default function (state = count, action) {
switch (action.type) {
case "Increment":
count++;
break;
case "Decrement":
count--;
break;
}
return count;
}这里是根据触时不同条件要执行的业务，例如数字的增加和减少。假如项目下有很多触发业务集合，我们需要把他们归纳一起，并且方便获取状态值获取，新建 ./src/store/index.js ：
import {combineReducers} from "redux";
import countReducer from "./reducers/counter";
const allReducers = combineReducers({
count: countReducer,
});
export default allReducers;然后需要有个动作器来触发上面的业务，新建 ./src/store/actions/counter.js ：
export function increment() {
return {
type: "Increment"
};
}
export function decrement() {
return {
type: "Decrement"
};
}如果需要改动状态值只能从上面的函数进行触发，这是唯一入口。
下面就编写页面进行测试，新建 ./src/screens/reduxDemo/index.js ：
import React, {Component} from "react";
import {Container, Content, Text, Card, Header, Body, Button, Title, CardItem} from "native-base";
import {increment, decrement} from "../../store/actions/counter";
import {bindActionCreators} from "redux";
import {connect} from "react-redux";
class Counter extends Component {
render() {
console.log(this.props.count);
return (
<Container>
<Header>
<Body>
<Title>Redux 计数器</Title>
</Body>
</Header>
<Content padder>
<Card>
<CardItem>
<Text>
{this.props.count}
</Text>
</CardItem>
</Card>
<Text/>
<Button block onPress={() => this.props.increment()}>
<Text>增加</Text>
</Button>
<Text/>
<Button block onPress={() => this.props.decrement()}>
<Text>减少</Text>
</Button>
</Content>
</Container>
);
}
}
function mapStateToProps(state) {
return {
count: state.count // 这里等效于 prop.state 不过redux1帮你封装好的
};
}
function matchDispatchToProps(dispatch) {
return bindActionCreators({increment: increment, decrement: decrement}, dispatch); // 绑定动作事件
}
export default connect(mapStateToProps, matchDispatchToProps)(Counter); // 连接Redux