Reactjs 如何从useState更改为useReducer
下面的代码我正试图将其转换为useReducer,但有几件事我无法理解。在下面的代码中,handleClick更新状态并调用其他函数以执行进一步的操作。在useReducer中,我可以更新状态,但不知道如何调用其他函数Reactjs 如何从useState更改为useReducer,reactjs,use-reducer,Reactjs,Use Reducer,下面的代码我正试图将其转换为useReducer,但有几件事我无法理解。在下面的代码中,handleClick更新状态并调用其他函数以执行进一步的操作。在useReducer中,我可以更新状态,但不知道如何调用其他函数 const handleClick = (id) =>{ let matchedEl = userArray.find(el => el.pic == picArray[id].pic) if(matchedEl){ alert('g
const handleClick = (id) =>{
let matchedEl = userArray.find(el => el.pic == picArray[id].pic)
if(matchedEl){
alert('game over')`
setUserArray([]);
gameOver();
} else {
let picObj = { "pic": picArray[id].pic}
setUserArray([...userArray, picObj]) //updates the state
if(userArray.length == 12){
setUserArray([])
scoreFn();
return;
}
let shuffledArray = shufflePicArray();
setPicArray([...shuffledArray]) //updates the state
scoreFn();
}
}
return (
<Container >
<Card onClick={() => handleClick(id)} /> </Card>
</Row>
</Container>)}
consthandleclick=(id)=>{
让matchedEl=userArray.find(el=>el.pic==picArray[id].pic)
if(matchedEl){
警报(“游戏结束”)`
setUserArray([]);
gameOver();
}否则{
设picObj={“pic”:picArray[id].pic}
setUserArray([…userArray,picObj])//更新状态
if(userArray.length==12){
setUserArray([]))
scoreFn();
返回;
}
设ShuffleArray=ShuffleArray();
setPicArray([…shuffledArray])//更新状态
scoreFn();
}
}
返回(
handleClick(id)}/>
)}
与useReducer
const initialState = {
picArray: pics,
userArray: []
}
function reducer(state, action){
switch(action.type){
case "handleClick" :
{
let id = action.payload;
const shuffledArray = state.picArray.sort( () => Math.random() - 0.5)
let matchedEl = state.userArray.find(el => el.pic == state.picArray[id].pic)
console.log(matchedEl)
let picObj;
if(!matchedEl){
picObj = { "pic": state.picArray[id].pic}
} else {
alert('game over')
gameOver(); //can't call the function is not defined yet
}
return{
state,
picArray:[...shuffledArray], //this works
userArray:[...state.userArray, picObj] //this works
}
}
default:
return state;
}
}
const Newmain = ({scoreFn, gameOver}) => {
const [state, dispatch] = useReducer(reducer, initialState)
return(
<card onClick={() =>dispatch({type:'handleClick', payload:id})} />
)}```
The useState handleClick function does a lot more things and how to reproduce while using useReducer.
const initialState={
picArray:图片,
用户数组:[]
}
功能减速机(状态、动作){
开关(动作类型){
案例“handleClick”:
{
设id=action.payload;
const shuffledArray=state.picArray.sort(()=>Math.random()-0.5)
让matchedEl=state.userArray.find(el=>el.pic==state.picArray[id].pic)
console.log(matchedEl)
让picObj;
如果(!matchedEl){
picObj={“pic”:state.picArray[id].pic}
}否则{
警报(“游戏结束”)
gameOver();//无法调用尚未定义的函数
}
返回{
国家,,
picArray:[…shuffledArray],//这很有效
userArray:[…state.userArray,picObj]//这是有效的
}
}
违约:
返回状态;
}
}
const Newmain=({scoreFn,gameOver})=>{
const[state,dispatch]=useReducer(reducer,initialState)
返回(
分派({type:'handleClick',payload:id})}/>
)}```
useState handleClick函数在使用useReducer时做了很多事情,以及如何进行复制。
要回答您的问题,您可以添加
consthandleclick=(id)=>{
//在这里做事
分派({type:'handleClick',负载:id})
}