反应+还原。 Connect 不更新组件的状态答案

【问题标题】：React+Redux. Connect doesn't update state of component反应+还原。 Connect 不更新组件的状态
【发布时间】：2018-10-30 22:44:42
【问题描述】：

我对 Redux 有一些问题。我创建了 Reduser，它工作正常。它改变了存储，我可以在 ReduxDevTools 中显示它。但是在组件状态下不会更新。

我有mapStateToProps, mapDispatchToProps, connect,，它在文档中看起来都像，但它不起作用。

index.js

import React from 'react';
import ReactDOM from 'react-dom';
import './css/index.css';
import App from './components/App.jsx';

import { createStore } from 'redux';
import { Provider } from 'react-redux';
import storeApp from './reducers';



let store = createStore(
    storeApp,
    window.__REDUX_DEVTOOLS_EXTENSION__ && window.__REDUX_DEVTOOLS_EXTENSION__()
    );



ReactDOM.render( 
    <Provider store={store}>
        <App />
    </Provider> , document.getElementById('root'));

它是我的 reducer，我在 combineReducers 中组合；

import {FIRST_ACTION, SECOND_ACTION ,THIRD_ACTION} from '../actions/actionTypes';

const firstRedus = (state = {}, action) => {

switch (action.type) {
    case FIRST_ACTION:
        return Object.assign({}, state, {
            test: action.text
        })
    case SECOND_ACTION:
        return Object.assign({}, state, {
            test: action.text
        })
    case THIRD_ACTION:
        return Object.assign({}, state, {
            test2: action.text
        })

    default:
        return state
 }
}
 export default firstRedus

这是我的 combineReducers

    import { combineReducers } from 'redux'
    import firstRedus from './firstRedus'


    export default combineReducers({
     firstRedus
    })

它是我的 App.jsx 组件

    import React, { PureComponent } from 'react';
    import '../css/App.css';

    import { connect } from 'react-redux'
    import { bindActionCreators } from 'redux'
    import {actFirst,actSec} from '../actions/actions.js';



    class App extends PureComponent {

        constructor(props) {
            super(props)
            this.state = {
                test: this.props.test
            }
            this.handleClick1= this.handleClick1.bind(this);
            this.handleClick2= this.handleClick2.bind(this);
        }
        handleClick1(e){
            e.preventDefault();
            this.props.actFirst('first')
        }
        handleClick2(e){
            e.preventDefault();
            this.props.actSec('scond')
        }   
        render() {
          return (
            <div className="App">
            <ul>
                <li>{this.state.test}</li> //doesn't work
                <li>{this.props.test}</li>  //doesn't work
            </ul>               
                <button onClick={this.handleClick1}>test1</button>  
                <button onClick={this.handleClick2}>test2</button>  
            </div>
          );
        }
    }

    function mapStateToProps(state){
        return {
            test: state.test        
        }
    };
    function mapDispatchToProps(dispatch,ownProps) {
        return {
            actFirst: (text) => {
                dispatch(actFirst(text));
            },
            actSec: (text) => {
                dispatch(actSec(text));
            }       
        }
    };

    export default connect(
      mapStateToProps,
      mapDispatchToProps
    )(App);

【问题讨论】：

在页面加载或handleClick1 和handleClick2 的onClick 操作期间的问题
你能展示你的 combineReducers 吗？
那是我的 combineReducers import { combineReducers } from 'redux' import firstRedus from './firstRedus' export default combineReducers({ firstRedus })
您可以将 mapStateToProps 更改为 test: state.firstRedus.test 。您的 firstRedus 处于测试状态
React native redux map state to props not working的可能重复

标签： reactjs redux components state connect

【解决方案1】：

你可以这样改

import React, { PureComponent } from 'react';
import '../css/App.css';

import { connect } from 'react-redux'
import { bindActionCreators } from 'redux'
import {actFirst,actSec} from '../actions/actions.js';



class App extends PureComponent {

    constructor(props) {
        super(props)
        this.state = {
            test: this.props.test
        }
        this.handleClick1= this.handleClick1.bind(this);
        this.handleClick2= this.handleClick2.bind(this);
    }
    handleClick1(e){
        e.preventDefault();
        this.props.dispatch(actFirst('first'))
    }
    handleClick2(e){
        e.preventDefault();
        this.props.dispatch(actSec('scond'))
    }   
    render() {
      return (
        <div className="App">
        <ul>
            <li>{this.state.test}</li> //doesn't work
            <li>{this.props.test}</li>  //doesn't work
        </ul>               
            <button onClick={this.handleClick1}>test1</button>  
            <button onClick={this.handleClick2}>test2</button>  
        </div>
      );
    }
}

function mapStateToProps(state){
    return {
        test: state.firstRedus.test        //change your state like this
    }
};

export default connect(mapStateToProps)(App);

【讨论】：