store 负责存储数据，相当于仓库，action负责dispatch派发数据，reducer负责接收处理数据然后交给store（个人理解 可能有些偏差 欢迎交流斧正）传统redux写法（旧）
//reducer
const counterReducer = (state = { counter: 0 }, action) => {
if (action.type === "increment") {
return {
counter: state.counter + 1,
};
}
if (action.type === "increase") {
return {
counter: state.counter + action.amount,
};
}
if (action.type === "decrement") {
return {
counter: state.counter - 1,
};
}
return state;
}
//连接到store
const store = createStore(counterReducer)使用reduxjs/toolkit（新）
新的写法主要体现在reducer的简化上
//reducer
const countSlice= createSlice(
{
name: "counter",
initialState: { counter: 0 },
reducers: {
increment(state) {
state.counter++;//在redux中这种写法不被允许 在toolkit中被允许
},
decrement(state) {
state.counter--;
},
increase(state, action) {
state.counter += action.payload;
},
}
}
)
//连接到store
const store = configureStore(
{
reducer: { counter: countSlice.reducer}//作为一个对象处理多reducer
}
)简单使用步骤
- 创建reducer文件
import { createSlice } from '@reduxjs/toolkit';
1. 创建切片
const uiSlice = createSlice({
name: 'ui',
initialState: { cartIsVisible: false },
reducers: {
toggle(state) {
state.cartIsVisible = !state.cartIsVisible;
}
}
});
3、将actions导出
export const uiActions = uiSlice.actions;
2、将切片导出
export default uiSlice;- 在store中引入reducer
import { configureStore } from '@reduxjs/toolkit';
import uiSlice from './ui-slice';
import cartSlice from './cart-slice';
4 在store中引入切片
const store = configureStore({
reducer: { ui: uiSlice.reducer, cart: cartSlice.reducer },
});
export default store;- 在index.js中包裹根组件
import ReactDOM from 'react-dom/client';
import { Provider } from 'react-redux';
import store from './store/index';
import './index.css';
import App from './App';
const root = ReactDOM.createRoot(document.getElementById('root'));
root.render(
<Provider store={store}>
<App />
</Provider>
);- 在组件中使用dispatch派发actions
import { useDispatch} from 'react-redux';
import { uiActions } from '../../store/ui-slice';
const dispatch = useDispatch();
const toggleCartHandler = () => {
dispatch(uiActions.toggle()); //5toggle 1步骤中reducer的action之一
};- 使用useSelecter接收数据
import { useSelector } from 'react-redux';
const Cart = (props) => {
const cartItems = useSelector((state) => state.cart.items);