React Native 新增 Redux 支援
0x1 前言
之前寫的專案都是人家編寫好的腳手架,裡面包含專案所需的環境檔案,但由於有些東西用不到打包增加軟體體積,所以自己從頭搭建個環境。是基於 Native Base +react-navigation + Redux的reactNative腳手架,現在專案環境如下:
{
"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-js x-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"
}
}
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0x2 新增 Redux 支援
這裡大概講解下安裝類庫支援:
yarn add yarn add react-navigation react-native-gesture-handler react-native-reanimated native-base
連結字型庫資源:
react-native link
react-navigation在 Android環境額外新增程式碼支援,具體情況文件:MainActivity.java
react-navigation在 react-native版本大於 0.60的時候不需要執行 react-native link連結。
由於專案需要狀態管理支援,故新增 Redux狀態管理類庫支援,在 React Native環境下和 React專案一樣:
yarn add redux react-redux redux-logger
redux-logger是監控狀態資料流日誌,可以在控制檯輸出狀態值的資訊。
由於專案基本環境是 Native Base環境,這裡怎麼安裝它就不再描述了,故在基礎專案下新增專案支援 Redux即可。開啟 ./src/App.js新增 Redux能力支援:
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)
); // 建立 Store
const AppNavigator = createStackNavigator(
{
ReduxDemo: {screen: reduxDemo},
},
{
initialRouteName: "ReduxDemo", // 路由入口
headerMode: "none", // 由於 react-navigation 預設導航欄自定義效果很差,故隱藏
},
);
const AppContainer = createAppContainer(AppNavigator);
export default () => (
<Provider store={store}>
<Root>
<AppContainer/>
</Root>
</Provider>
);
建立狀態觸發事件業務集 ./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;
}
這裡是根據觸時不同條件要執行的業務,例如數字的增加和減少。假如專案下有很多觸發業務集合,我們需要把他們歸納一起,並且方便獲取狀態值獲取,新建 ./src/store/index.js:
import {combineReducers} from "redux";
import countReducer from "./reducers/counter";
const allReducers = combineReducers({
count: countReducer,
});
export default allReducers;
然後需要有個動作器來觸發上面的業務,新建 ./src/store/actions/counter.js:
export function increment() {
return {
type: "Increment"
};
}
export function decrement() {
return {
type: "Decrement"
};
}
如果需要改動狀態值只能從上面的函式進行觸發,這是唯一入口。
下面就編寫頁面進行測試,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 計數器</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>減少</Text>
</Button>
</Content>
</Container>
);
}
}
function mapStateToProps(state) {
return {
count: state.count // 這裡等效於 prop.state 不過redux1幫你封裝好的
};
}
function matchDispatchToProps(dispatch) {
return bindActionCreators({increment: increment, decrement: decrement}, dispatch); // 繫結動作事件
}
export default connect(mapStateToProps, matchDispatchToProps)(Counter); // 連線Redux