Reactjs 如何在redux中使用API调用操作？

我是redux新手，我正在尝试让它与我的应用程序一起工作，但我在理解如何在其中使用异步操作方面遇到了问题。我的动作就是api调用。只要我的其他状态不是空的，就应该调用此操作。我没有收到任何错误，但不认为调用了我的操作，因为数据是空的。谁能帮助我理解我做错了什么

这是我的actions.js。wordsFetchData是我需要调用的操作：

 export function wordsFetchDataSuccess(items){
    return{
        type: 'WORDS_FETCH_DATA_SUCCESS',
        items
    };
 }

 export function wordsAreFetching(bool){
     return{
        type: 'WORDS_ARE_FETCHING',
        areFetching: bool
     }
 }

 export function wordsHasErrored(bool) {
     return {
        type: 'WORDS_HAS_ERRORED',
        hasErrored: bool
     };
 }

 export function wordsFetchData(parsed) {
    return (dispatch) => {
        dispatch(wordsAreFetching(true));

        fetch('URL', {
            method: "POST",
            headers: {
                "Content-type": "application/json"
            },body: JSON.stringify({
                 words: parsed
        })
    })
        .then((response) => {
            if (!response.ok) {
                throw Error(response.statusText);
            }

            dispatch(wordsAreFetching(false));

            return response;
        })
        .then((response) => response.json())
        .then((items) => dispatch(wordsFetchDataSuccess(items)))
        .catch(() => dispatch(wordsHasErrored(true)));
    };
 }

以下是我的减速机：

export function word(state = [], action) {
switch (action.type) {
    case 'WORDS_FETCH_DATA_SUCCESS':
        return action.items;

    default:
        return state;
    }
}

export function wordsAreFetching(state = false, action) {
    switch (action.type) {
        case 'WORDS_ARE_FETCHING':
            return action.areFetching;

        default:
            return state;
    }
}

export function wordsFetchHasErrored(state = false, action) {
    switch (action.type) {
        case 'WORDS_HAS_ERRORED':
           return action.hasErrored;

    default:
        return state;

    }

 }

这是我的componentDidMount函数：

componentDidMount = (state) => {
    this.props.fetchData(state);
};

这是终止后应调用操作的函数：

 parseInput = async () => {
    console.log(this.state.textInput);
    let tempArray = this.state.textInput.split(" "); // `convert 
    string into array`
    let newArray = tempArray.filter(word => word.endsWith("*"));
    let filterArray  = newArray.map(word => word.replace('*', ''));
    await this.setState({filterArray: filterArray});
    await this.props.updateData(this.state.filterArray);
    if (this.state.projectID === "" && this.state.entity === "")
        this.dialog.current.handleClickOpen();
    else
        if (this.state.filterArray.length !== 0)
            this.componentDidMount(this.state.filterArray);
    };

这些是MapStateTops和mapDispatchToProps函数

const mapStateToProps = (state) => {
    return {
        items: state.items,
        hasErrored: state.wordsFetchHasErrored,
        areFetching: state.wordsAreFetching
    };
};

const mapDispatchToProps = (dispatch) => {
    return {
        fetchData: wordsFetchData
    };
};

---

执行抓取只需一个操作（即

WORDS\u正在抓取

），其余情况（即

WORDS\u已出错

，

WORDS\u抓取数据成功

）可以在减速机内处理

你的行动：

 export function wordsAreFetching(){
     return{
        type: 'WORDS_ARE_FETCHING',
     }
 }

您的新减速机：

export function word(state = [], action) {
switch (action.type) {
    case 'WORDS_ARE_FETCHING':
        return {...state, error: false, areFetching: true};
    case 'WORDS_FETCH_DATA_SUCCESS':
        return {...state, items: action.payload , areFetching: false};
    case 'WORDS_HAS_ERRORED':
        return {...state, error: true, areFetching: false};
    default:
        return state;
}

从此处获取数据后，您可以触发

WORDS\u FETCH\u DATA\u SUCCESS

：

export function wordsFetchData() {
    try {
        const response = await axios.get(YOUR_URL);
        return dispatch({ type: WORDS_FETCH_DATA_SUCCESS, payload: response.data });
    } catch (err) {
        return dispatch({ type: WORDS_HAS_ERRORED });
    }
 }

看看这个，它使用的axios可以帮助您进行异步调用。

以下几点：

无需将状态传递到您的

组件didmount

，您的

mapDispatchToProps

未使用它

以下是构建这些功能的建议。它们更简洁易读

其他注意事项和有用的东西： 如果您使用的是thunk，那么作为第二个参数，您可以访问这里的整个redux存储。例如：

    return (dispatch, getState) => {
        dispatch(wordsAreFetching(true));
        console.log('getState', getState());
       const { words } = getState().items;
// This is a great place to do some checks to see if you _need_ to fetch any data!
// Maybe you already have it in your state?

     if (!words.length) {
        fetch('URL', {
            method: "POST",
            headers: {
                ......
      }

    })

---

我希望这能有所帮助，如果您还需要什么，请随时询问。

您使用过redux thunk或redux saga之类的中间件吗？是的，redux-thunk@RajSaraogi我想问题在于我说的不对

    return (dispatch, getState) => {
        dispatch(wordsAreFetching(true));
        console.log('getState', getState());
       const { words } = getState().items;
// This is a great place to do some checks to see if you _need_ to fetch any data!
// Maybe you already have it in your state?

     if (!words.length) {
        fetch('URL', {
            method: "POST",
            headers: {
                ......
      }

    })