React Native Redux createStore error:undefined is not an object(evaluating 'action.type')

Question

我正在使用 Redux 和 ReactNative，我想用 reducer 创建一个商店

而且，我在下面遇到错误，指向 reducer.js

中函数 switchToTab() 中的第 'switch (action.type)' 行

undefined is not an object(evaluating 'action.type')

这是我的 actions.js

export const SWITCH_TAB = 'switchTab'

export function switchTab(index) {

return {
    type: SWITCH_TAB,
    index: index
}

}

这是我的 reducer.js

import { SWITCH_TAB } from './actions.js'

export function switchToTab(state = {}, action) {

switch (action.type) {//error point to this line

    case SWITCH_TAB:
        return Object.assign({}, ...state, {
            index: action.index
        });
    break;

    default:
        return state;
}

}

这里是 createStore:

import { createStore } from 'redux';
import { switchToTab } from './reducer.js'

export default class MainPage extends Component {
    constructor(props) {
    super(props);
    this.state = {
        index:0
    };

    let store = createStore(switchToTab());
}

Answer 1

创建商店时不调用减速器。 createStore 接受一个 reducer 函数作为它的第一个参数。

import { createStore } from 'redux';
import { switchToTab } from './reducer.js'

export default class MainPage extends Component {
    constructor(props) {
    super(props);
    this.state = {
        index:0
    };

    let store = createStore(switchToTab); // dont call this here, just pass it
}

React Native Redux createStore error:undefined is not an object(evaluating 'action.type')

React Native Redux createStore error:undefined is not an object(evaluating 'action.type')

javascript

react-native

redux

react-redux