React-Redux连接无法正常工作

Question

我试图在我的codepen笔中使用React + Redux,但是连接不是注入prop,

也许是因为作为一个业余爱好者,我错过了一些东西.请看一看. http://codepen.io/sahil28v/pen/EKEKME?editors=0010

const { Component } = React;
const { createStore, bindActionCreators, applyMiddleWare, combineReducers } =     Redux;
const { Provider, connect } = ReactRedux;

const Application = () =>  (
        <div className="ground">
    <Tmap />
        </div>
    );

class Tmap extends Component {
  constructor(props){
  super(props);
  console.log(this.props.mapstate);  // This is returning undefined,no idea why
  console.log(store.getState().mapstate); // Though this returns val: "hey" as it should properly though.
 }
 render () {
  return (
   <div>

   </div>
  );
 }
}

const mapStateToProps = (state) => ({
mapstate: state.mapstate
});

connect(mapStateToProps)(Tmap);

const initialState = {
  val: "hey"
}

const mapReducer = (state = initialState, action) => {
 return state ;
} ;

const rootReducer = combineReducers({
  mapstate: mapReducer,
});

const store = createStore(rootReducer);

React.render(
    <Provider store={store}>
        <Application />
    </Provider>, document.getElementById('app')
);

另外,,,我可以在codepen本身配置存储以使用redux devtools(chrome扩展).我试过添加... window.devToolsExtension？window.devToolsExtension():f => f,到创建商店但不起作用.

当有人回答时 - 您是否也可以推荐好的文档/视频: - >学习ES6 ...

- 谢谢您的帮助

Answer 1

Connect返回我想要的组件的新实例.这可以使用connect作为装饰器.

@connect(
  state => ({
    mapstate: state.mapstate 
  })
)
class Tmap extends Component {
  constructor(props){
    super(props);
    alert(this.props.mapstate);  // This is returning undefined,no idea why
    alert(store.getState().mapstate); //As I understand this is the direct low level api which connect is meant to abstract away along with store.subscribe.
  }

  render () {
    return (
    <div>
    </div>
    );
  }
}

Answer 2

您忘记将连接结果保存到新变量中.而这个新变量就是你应该使用的而不是Tmap.

const CTmap = connect(... 
.... 
<CTmap/>