redux & react-redux结合使用 2024

redux & react-redux结合使用 2024

1.安装 redux react-redux

yarn add redux && yarn add react-redux

2.编写reducer

const initstate={count:0}
exports.reducer=(state=initstate,action)=>{
    switch (action.type){
        case "add_action":
            return {
                count: state.count+1
            }
        default:
            return state;
    }
}

3.编写store

import {createStore} from "redux";
import {reducer} from '../reducer'
const store=createStore(reducer)
export default store

4.根组件引入provider

import Home from "./pages/home";
import ComA from "./pages/ComA";
import ComB from "./pages/ComB";
import store from "./store";
import {Provider} from "react-redux";

function App() {
  return (
      <Provider store={store}>
          <div>
              <ComA/>
              <ComB/>
          </div>
      </Provider>
  );
}
export default App;

5.发送状态

import React from "react";
import {connect} from "react-redux";
class ComA extends React.Component{
    handleClick=()=>{
        console.log(111)
        this.props.sendAction()
    }
    render() {
        return (
            <button onClick={this.handleClick}>+</button>
        )
    }
}
const mapDispatchToProps=(dispatch)=>{
    return {
        sendAction:()=>{
            dispatch({
                type:'add_action'
            })
        }
    }

}
export default connect(null,mapDispatchToProps)(ComA)

6.接收状态

import React from "react";
import {connect} from "react-redux";
class ComB extends React.Component{
    render() {
        return (
            <button>{this.props.count}</button>
        )
    }
}
const mapStateToProps=state=>{
    return state
}
export default connect(mapStateToProps)(ComB)