React Redux チュートリアル: Redux を使用してフロントエンドの状態を管理する方法

npm install redux react-redux

import { createStore } from 'redux';

// 初始状态
const initialState = { count: 0 };

// Reducer函数
function reducer(state = initialState, action) {
  switch (action.type) {
    case 'INCREMENT':
      return { ...state, count: state.count + 1 };
    case 'DECREMENT':
      return { ...state, count: state.count - 1 };
    default:
      return state;
  }
}

// 创建store
const store = createStore(reducer);

export default store;

import React from 'react';
import ReactDOM from 'react-dom';
import { Provider } from 'react-redux';
import store from './store';
import App from './App';

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

import React from 'react';
import { connect } from 'react-redux';

class Counter extends React.Component {
  increment = () => {
    this.props.dispatch({ type: 'INCREMENT' });
  };

  decrement = () => {
    this.props.dispatch({ type: 'DECREMENT' });
  };

  render() {
    return (
      <div>
        <h1>计数器：{this.props.count}</h1>
        <button onClick={this.increment}>增加</button>
        <button onClick={this.decrement}>减少</button>
      </div>
    );
  }
}

function mapStateToProps(state) {
  return { count: state.count };
}

export default connect(mapStateToProps)(Counter);

import React from 'react';
import Counter from './Counter';

class App extends React.Component {
  render() {
    return <Counter />;
  }
}

export default App;