Question

我正在努力弄清楚我的行动的返回类型应该是什么。在我使用any时，一切正常，但我正在努力避免使用any。

export const saveValue = (value: number): any => {
    return (dispatch: Dispatch<SaveValue>, getState: () => State): void => {
        axios.post('www.exampleurl.com', value)
            .then((response) => {
                const someValueFromState = getState().stateValue;
                const payload = {...response, someValueFromState}
                dispatch({ type: constants.SAVE_VALUE, payload });
            });
    };
};

我在操作未使用getState()之前让它工作，它看起来像这样，返回Dispatch<SaveValue>：

export const saveValue = (value: number): Dispatch<SaveValue> => {
    return (dispatch: Dispatch<SaveValue>): void => {
        axios.post('www.exampleurl.com', value)
            .then((response) => {
                dispatch({ type: constants.SAVE_VALUE, response });
            });
    };
};

但是一旦我添加了getState，我不知道该怎么做了。我试图将返回值放在变量中，并且可以看到我创建的对象是const myAttempt: (dispatch: Dispatch<SaveValue>, getState: () => State) => void但是当我尝试使用它时，它不起作用：

export const saveValue = (value: number): (dispatch: Dispatch<SaveValue>, getState: () => StoreState) => void => {
    return (dispatch: Dispatch<SaveValue>, getState: () => State): void => {
        axios.post('www.exampleurl.com', value)
            .then((response) => {
                const someValueFromState = getState().stateValue;
                const payload = {...response, someValueFromState}
                dispatch({ type: constants.SAVE_VALUE, payload });
            });
    };
};

这样做，我收到错误：A function whose declared type is neither 'void' nor 'any' must return a value.

编辑：

只是要添加，我不能像以前一样返回Dispatch<SaveValue>，否则我会收到此错误：Type '(dispatch: Dispatch<SaveValue>, getState: () => State) => void' is not assignable to type 'Dispatch<SaveValue>'

Answer 1

一位朋友帮我解答了这个问题。这是正确的方法：

export const saveValue = (value: number): (dispatch: Dispatch<SaveValue>, getState: () => State): void => {
    return (dispatch: Dispatch<SaveValue>, getState: () => State): void => {
        axios.post('www.exampleurl.com', value)
            .then((response) => {
                const someValueFromState = getState().stateValue;
                const payload = {...response, someValueFromState}
                dispatch({ type: constants.SAVE_VALUE, payload });
            });
    };
};

我遇到的问题是我的mapDispatchToProps函数被明确输入并导致错误Type '(dispatch: Dispatch<SaveVisit>, getState: () => StoreState) => void' is not assignable to type 'Dispatch<SaveVisit>'。功能是：

interface MapDispatchToPropsInterface {
    saveValue : (value: number) => Dispatch<SaveValue>;
}

const mapDispatchToProps: MapDispatchToPropsInterface = {
    saveValue : ActionCreators.saveValue,
};

但界面必须是：

interface MapDispatchToPropsInterface {
    saveValue : (saveDetails: CheckedVisit) =>  (dispatch: Dispatch<SaveValue>, getState: () => StoreState) => void;
}

使用dispatch和getState

1 个答案: