点击加减按钮,延迟1秒操作加减动作(模拟异步网络请求)
最终调用Action “Done” 将结果展示
import React from 'react'
import ReactDOM from 'react-dom'
import {createStore,applyMiddleware} from 'redux'
import {Provider,connect} from 'react-redux'
import createSagaMiddleware,{takeEvery} from 'redux-saga'
import {put,fork} from 'redux-saga/effects'
function reducers(state=0,action) {
switch (action.type) {
case 'Done':
return state + action.payload;
default:
return state;
}
};
export function* AddAsync() {
yield new Promise(function (resolve) {
setTimeout(function () {
resolve()
},1000)
})
yield put({type: 'Done',payload: 1})
}
export function* SubAsync() {
yield new Promise(function (resolve) {
setTimeout(function () {
resolve()
},payload: -1})
}
function* watchIncrementAsync() {
yield* takeEvery('ADD',AddAsync)
}
function* watchDecrementAsync() {
yield* takeEvery('SUB',SubAsync)
}
var sagaMiddleware = createSagaMiddleware();
const store = createStore(reducers,applyMiddleware(sagaMiddleware))
function* root() {
yield [
fork(watchDecrementAsync),fork(watchIncrementAsync)
]
}
sagaMiddleware.run(root)
const ResultIn = (props) => <div>结果:{props.value}</div>
const Result = connect(
mapStateToPropsResult
)(ResultIn)
var AppIn = (props) => <div>
<span onClick={() => {
props.onChangeAdd()
}}>点我加1</span>
<span onClick={() => {
props.onChangeSub()
}}>点我减1</span>
<Result/></div>
function mapStateToPropsResult(state) {
return {
value: state
}
}
function mapStateToProps(state) {
return {
value: state
}
}
function mapDispatchToProps(dispatch) {
return {
onChangeAdd: () => {
dispatch({type: 'ADD',payload: 1});
},onChangeSub: () => {
dispatch({type: 'SUB',payload: 1});
}
}
}
const App = connect(
mapStateToProps,mapDispatchToProps
)(AppIn)
ReactDOM.render(
<Provider store={store}>
<App/>
</Provider>,document.getElementById('root')
)