Redux基础使用

Redux基础使用：

简介：这里是从需求来响应的执行操作redux，所以理解起来更加的容易
铭记在心的三点：action／reducer／store 除此之外就是react／react native的基础组件

需求：实现一个数字的加减1和重置

实现：

1:在组件内部使用this.setState（）来操控
2:将数据独立起来，使用redux来操控
这里阐述第二种类： 首先下npm下依赖：

    "react-redux": "^4.4.5",
    "redux": "^3.5.2",

1：创建actionTyprs，定义执行的类型名称

export const INCREASE = 'INCREASE';//加
export const DECREASE = 'DECREASE';//减
export const RESET = 'RESET';//重置

2:创建actions.js,action的函数，给组件使用

import { INCREASE, DECREASE, RESET } from './actionsTypes';
const increase = () => ({ type: INCREASE });
const decrease = () => ({ type: DECREASE });
// const reset = () => ({ type: RESET });
var reset = function reset(JD) {
  console.log("case"+JD);
  return { type: RESET,
    parms:JD//从组件那边传递来的参数
  };
};

export {
    increase,
    decrease,
    reset
}

3：创建reducer.js（具体怎么操作）

import { combineReducers } from 'redux';
import { INCREASE, DECREASE, RESET} from './actionsTypes';
// 原始默认state,数据
const defaultState = {
  count: 0,
  factor: 1
}
//这里数据是从defaultState或者从组件那边过来，也就实现了数据的传递
function counter(state = defaultState, action) {
  console.log("action");
  console.log(action);
  console.log("state");
  console.log(state);
  switch (action.type) {
    case INCREASE:
      return { ...state, count: state.count + state.factor };
    case DECREASE:
      return { ...state, count: state.count - state.factor };
    case RESET:
      return { ...state, count: action.parms };
    default:
      return state;
  }
}

export default combineReducers({
    counter
});

4:创建全局的store.js,存放共享数据

import { createStore, applyMiddleware, compose } from 'redux';
// import createLogger from 'redux-logger';
import rootReducer from './reducers';
const configureStore = preloadedState => {
    return createStore (
        rootReducer,
        // preloadedState,
        // compose (
        //     applyMiddleware(createLogger())
        // )
    );
}

const store = configureStore();

export default store;

5: 将redux和react／react native的组件结合

import React, { Component } from 'react';
import { Provider } from 'react-redux';
import Home from './home';
import store from './store';

export default class test extends Component {
 render() {
   return (
     <Provider store={store}>
       <Home/>
     </Provider>
   );
 }
}

6:具体的页面的组件：

import React, { Component } from 'react';
import {
 StyleSheet,
 Text,
 View,
 TouchableOpacity
} from 'react-native';
import { connect } from 'react-redux';
import { increase, decrease, reset } from './actions';

class Home extends Component {
 _onPressReset() {
   this.props.dispatch(reset(80));
 }

 _onPressInc() {
   this.props.dispatch(increase());
 }

 _onPressDec() {
   this.props.dispatch(decrease());
 }

 render() {
   return (
     <View style={styles.container}>
       <Text style={styles.counter}>{this.props.counter.count}</Text>
       <TouchableOpacity style={styles.reset} onPress={()=>this._onPressReset()}>
         <Text>归零</Text>
       </TouchableOpacity>
       <TouchableOpacity style={styles.start} onPress={()=>this._onPressInc()}>
         <Text>加1</Text>
       </TouchableOpacity>
       <TouchableOpacity style={styles.stop} onPress={()=>this._onPressDec()}>
         <Text>减1</Text>
       </TouchableOpacity>
     </View>
   );
 }
}

const styles = StyleSheet.create({
 container: {
   flex: 1,
   alignItems: 'center',
   justifyContent: 'center',
   flexDirection: 'column'
 },
 counter: {
   fontSize: 50,
   marginBottom: 70
 },
 reset: {
   margin: 10,
   backgroundColor: 'yellow'
 },
 start: {
   margin: 10,
   backgroundColor: 'yellow'
 },
 stop: {
   margin: 10,
   backgroundColor: 'yellow'
 }
})

const abc = state => ({
   counter: state.counter
})

export default connect(abc)(Home);

参考文档：http://blog.csdn.net/sinat_17775997/article/details/70176701