React演示组件无法使用反应容器从redux商店读取值
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我是stackoverflow的新手,并且使用react / redux是一个新手。我已经扫描了很多帖子,看看是否有类似的帖子可以给我一个答案,但我仍然感到困惑。
我目前有一个演示组件“Repetitions”和一个容器组件,用于从redux store获取props,并从presentational组件到redux store调度操作。当我在输入字段中输入数据时,我的表示组件更新了redux存储,但是我想使用redux存储来检索输入值,这样当用户第一次进入页面时输入值为“0”这是redux商店内的初始值。
我最初使用react / redux制作了一个简单的Counter组件,它工作正常。我已经制作了“Repetition”组件并更改了redux存储以使用combinedreducer,这就是问题似乎开始的时候,因为这两个组件都无法读取redux存储。
Rootreducer.ts
import { combineReducers } from "redux";
import countReducer from "./example/reducer";
import repetitionsReducer from "./reps/reducer";
const rootReducer = combineReducers({
countReducer,
repetitionsReducer
})
export default rootReducer;
RepetitionsReducer.ts
import { RepetitionsState } from "../types";
import { AddRepetitionsAction } from "./actions";
export type RepetitionsActionType = AddRepetitionsAction;
export type Dispatch = (action: RepetitionsActionType) => void;
// The reducer updates the count
const initialState: RepetitionsState = {
repetitions: 0
};
const repetitionsReducer = (
state = initialState,
action: RepetitionsActionType
): RepetitionsState => {
switch (action.type) {
case "ADD_REPETITIONS":
return { ...state, repetitions: action.repetitions };
default:
return state;
}
}
export default repetitionsReducer;
RepetitionsContainer.ts
import { connect } from "react-redux";
import { RootState } from "../../store/types";
import { Dispatch } from "../../store/reps/reducer";
import { addRepetitions } from "../../store/reps/actions";
import Repetitions from "../../components/reps/Repetitions";
interface StateFromProps {
repetitions: number ;
}
interface DispatchFromProps {
updateRepetitions: (repetitions: number) => void;
}
export type RepetitionsProps = StateFromProps & DispatchFromProps;
const mapStateToProps = (state: RootState): StateFromProps => ({
repetitions: state.repetitions
});
const mapDispatchToProps = (dispatch: Dispatch): DispatchFromProps => ({
updateRepetitions: (repetitions: number) => dispatch(addRepetitions(repetitions))
});
export default connect(
mapStateToProps,
mapDispatchToProps
)(Repetitions);
RepetitionsComponent.ts 注意:当我尝试console.log“重复”时,我现在没有被定义。
import React from "react";
import { RepetitionsProps } from "../../containers/reps/Repetitions";
const Repetitions: React.FunctionComponent<RepetitionsProps> = ({
repetitions,
updateRepetitions
}) => {
console.log(repetitions)
return (
<div>
<h3>Reps</h3>
<input
onChange={(event) => updateRepetitions(Number(event.target.value))}
value={ repetitions } // <-- This is the value i'm wanting to present to the user from the redux store
/>
</div>
);
};
export default Repetitions;
App.ts
import React from "react";
import ReactDOM from "react-dom";
import * as serviceWorker from "./serviceWorker";
import Header from "./components/header/Header";
import { Provider } from "react-redux";
import { createStore } from "redux";
import Counter from "./containers/example/Counter";
import Repetitions from "./containers/reps/Repetitions";
import { composeWithDevTools } from 'redux-devtools-extension';
import rootReducer from "./store/reducer";
const store = createStore(rootReducer, composeWithDevTools());
console.log(store.getState())
function App() {
return (
<div className="App">
<Header title={"Rep count"} />
<Repetitions />
<br />
<br />
<br />
<Counter />
</div>
);
}
const rootElement = document.getElementById("root");
ReactDOM.render(
<Provider store={store}>
<App />
</Provider>,
rootElement
);
当用户首次加载页面时,我希望看到的预期结果是“Reps”标题下面的输入框中显示的“0”。相反,该框为空,但redux商店将重复值显示为“0”。
还值得注意的是,当我第一次加载页面时,输入字段下方的计数器用于从redux存储区读取“0”,但现在它也是未定义的。
感谢您抽出宝贵时间查看我的帖子。任何帮助将不胜感激!
嗯......这里有些不对劲:
首先,你的重复状态目前正在持有一个对象。它应该包含一个简单的数字。
其次,当您尝试在mapStateToProps中获取重复状态时,商店中的重复状态的名称(来自您附加的快照)是“repetitionReducer”而不是“重复”:
const mapStateToProps = (state: RootState): StateFromProps => ({
repetitions: state.repetitions // <- this one here...
});
希望这可以帮助 :)
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