Redux 狀態管理2

Redux 和React 如何一起使用

*把store.dispatch 方法傳遞給組件 ,內部可以調用修改狀態
*Subscribe 訂閱 render 函數 ,每次修改都重新渲染
*Redux相關文件 , 移動到 單獨文件 index.redux.js

index.js

import React from "react"
import ReactDom from "react-dom"
import { createStore } from "redux"
import App from "./App"
import { counter } from "./index.redux"

const store = createStore(counter)
function render (){

    ReactDom.render(<App store = {store} />,document.getElementById("root"))

}
render ()
store.subscribe(render)

App.js

import React from "react"
import { ADDGUN } from "./index.redux"
import { Button } from "antd-mobile"

class App extends React.Component{
    // constructor(props){
    //     super(props);
    // }
    render(){
        const store = this.props.store
        const num = store.getState()
        return(
            <div>
                <h1>現在有機槍{num}把</h1>
                <Button type="danger" onClick={()=>store.dispatch( ADDGUN())}>申請武器</Button>
            </div>
        )
    }
}

export default App

index.redux.js

const ADD_GUN = "加機關槍"
const REMOVE_GUN = "減機關槍"
const FAKE_GUN = "搶機關槍"


/*reducer*/
export function counter (state=0,action){
    switch(action.type){
        case ADD_GUN:
            return state + 1
        case REMOVE_GUN:
            return state - 1
        case FAKE_GUN:
            return state * 1000
        default:
            return 10
    }
}

export function ADDGUN(){
    return {type:ADD_GUN}
}

export function REMOVEGUN(){
    return {type:REMOVE_GUN}
}

export function FAKEGUN(){
    return {type:FAKE_GUN}
}