action.type 在 redux 中未定义

Question

redux 出现错误：action.type 未定义。我已将其范围缩小到我的一项操作：

export function LOAD_PRODUCTS() {
    axios.get('http://localhost:3000/api/products')
    .then((res) => {
        return (dispatch) => {
            dispatch({type: 'PRODUCTS_LOADED', payload: res})
        }
    }) 
    .catch((err) => {
        return (dispatch) => {
            dispatch({type: "PRODUCTS_ERROR", payload: err})
        }
    })
}

或者也许是减速器...

export function reducer(
    state = {
        fbkey: '',
        userSuccess: null,
        cart: [],
        nav: null,
        tab: true,
        error: {}, 
        loading: false,
        products: []
    }, action) {


    switch (action.type) {
          case "FBTOKEN": {
            return {
                ...state,
                fbkey: action.payload
            }
          }

        case "NAV_OPEN" : {
            return {
                ...state, 
                nav: true
            }
        }

        case "NAV_CLOSE" : {
            return {
                ...state,
                nav: false
            }
        }

        case "USER_SUCCESS" : {
            return {
                ...state, 
                userSuccess: true
            }
        }

        case "USER_ERROR" : {
            return { 
                ...state,
                userSuccess: false
            }
        }

        case "ADD_TO_CART" : {
            return {
                ...state,
                cart: action.payload
            }
        }
        case "TAB_CLOSE": {
            return {
                ...state,
                tab: action.payload
            }
        }

        case "TAB_OPEN": {
            return {
                ...state, 
                tab: action.payload
            }
        }

        case "PRODUCTS_LOADED": {
            return {
                ...state,
                products: action.payload
            }
        }

        case "PRODUCTS_ERROR": {
            return {
                ...state, 
                error: action.payload
            }
        }

        case "IS_LOADING": {
            return {
                ...state, 
                loading: action.payload
            }
        }

        case "IS_NOT_LOADING": {
            return {
                ...state,
                loading: action.payload
            }
        }

        default: {
            return {
                ...state
            }
        }
    }
}

所以，不知何故，类型没有正确返回。我该如何解决？

编辑：这里正在使用 Thunk。我还添加了减速器代码。返回调度函数也不起作用。或许与此有关？

Answer 1

你需要返回 dispatch 试试下面的代码

export function LOAD_PRODUCTS() {
    axios.get('http://localhost:3000/api/products')
    .then((res) => {
        return (dispatch) => {
            return dispatch({type: 'PRODUCTS_LOADED', payload: res})
        }
    }) 
    .catch((err) => {
        return (dispatch) => {
            return dispatch({type: "PRODUCTS_ERROR", payload: err})
        }
    })
}