我只是在制作一个简单的应用程序来学习 redux 的异步。我已经让一切正常,现在我只想在网页上显示实际状态。现在,我如何在渲染方法中实际访问商店的状态?
这是我的代码(所有内容都在一页中,因为我只是在学习):
const initialState = {
fetching: false,
fetched: false,
items: [],
error: null
}
const reducer = (state=initialState, action) => {
switch (action.type) {
case "REQUEST_PENDING": {
return {...state, fetching: true};
}
case "REQUEST_FULFILLED": {
return {
...state,
fetching: false,
fetched: true,
items: action.payload
}
}
case "REQUEST_REJECTED": {
return {...state, fetching: false, error: action.payload}
}
default:
return state;
}
};
const middleware = applyMiddleware(promise(), thunk, logger());
const store = createStore(reducer, middleware);
store.dispatch({
type: "REQUEST",
payload: fetch('http://localhost:8000/list').then((res)=>res.json())
});
store.dispatch({
type: "REQUEST",
payload: fetch('http://localhost:8000/list').then((res)=>res.json())
});
render(
<Provider store={store}>
<div>
{ this.props.items.map((item) => <p> {item.title} </p> )}
</div>
</Provider>,
document.getElementById('app')
);
因此,在状态的渲染方法中,我想列出商店中的所有 item.title
。
谢谢
最佳答案
您应该创建单独的组件,它将监听状态变化并在每次状态变化时更新:
import store from '../reducers/store';
class Items extends Component {
constructor(props) {
super(props);
this.state = {
items: [],
};
store.subscribe(() => {
// When state will be updated(in our case, when items will be fetched),
// we will update local component state and force component to rerender
// with new data.
this.setState({
items: store.getState().items;
});
});
}
render() {
return (
<div>
{this.state.items.map((item) => <p> {item.title} </p> )}
</div>
);
}
};
render(<Items />, document.getElementById('app'));
关于javascript - 我如何在 React Redux 中访问存储状态?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/38332912/