与Redux存储分开更新React组件状态

Question

I have a react component which has a list of selectable items. I want the list to be hidden until the user clicks a button to show the list.

There is no reason for the 'showList' to be a part of the global store, as it only matters to this component.

I am using redux connect, and am having difficulting understanding how to access the local components this.setState as it is always undefined .

// Redux connect
import { connect } from 'react-redux'
import { setClockSpeed } from '../actions'
import SpeedControls from '../components/speedControl/SpeedControl'

let showList = false;
const mapStateToProps = (state) => {
  return {
    speed: state.clock.speed,
    speeds: [ 1, 5, 10, 25, 50, 100, 150, 200 ],
    showList
  }
}

const mapDispatchToProps = (dispatch) => {
  return {
    setClockSpeed: newSpeed => displatch(setClockSpeed(newSpeed)),
    toggleList: this.setState({showList: !showList}) //undefined here
  }
}

const PlayerSpeedControls = connect(
  mapStateToProps,
  mapDispatchToProps
)(SpeedControls)

export default PlayerSpeedControls

// Component
import React, { PropTypes } from 'react';

import style from './SpeedControl.css';


const getSpeedItemClass = (s, idx, speed, speeds) => {
  let speedClass = style.speedItem;
  if (idx === 0) speedClass += ' ' + style.lastSpeedItem;
  if (idx === speeds.length - 1 ) speedClass += ' ' + style.firstSpeedItem;
  if (s === speed) speedClass += ' ' + style.currentActiveSpeed;
  return speedClass
}



const SpeedControls = ({ setClockSpeed, toggleList, speed, speeds, showList }) => (
  <div className={style.speedControl}>
    <div className={style.speedList}>
      <ul className={showList ? style.speedOptions : style.hideSpeedOptions}>
        { speeds.map((s, idx) => {
          return <li key={idx} className={getSpeedItemClass(s, idx, speed, speeds)} onClick={(s) => { 
          }}>{s}x</li>
          })
        }
      </ul>
      <span className={style.currentSpeed} onClick={ toggleList || this.setState //undefined here too }>{speed}x</span>
    </div>
  </div>
);

SpeedControls.propTypes = {
  setClockSpeed: PropTypes.func.isRequired,
  speed: PropTypes.number.isRequired,
  speeds: PropTypes.array.isRequired
};

export default SpeedControls;

Answer 1

In the example provided, You are using react state less Component. You cannot access state in such components. Use normal components to have the state in component.

 class SpeedControls extends Component {
  render() {
  }
}

mapDispatchToProps is just utility function provided by react-redux, It is not a component.There is no way you can access or update state there.