我实际上正在构建一个井字游戏。但是这个错误实际上并没有让我更新历史记录。当我在学习 Skillshare.com 上的教程时,我和他做了同样的事情。但仍然出现错误。我是 React 的初学者。我使用 nano-react npm 项目来创建这个项目。 这是 App.js:
import React , {useState} from "react";
import Board from "./components/Board"
import History from "./components/History"
import {calculateWinner} from './support'
import StatusMessage from './components/StatusMessage'
import './styles/root.scss'
const NEW_GAME = [
{
board: Array(9).fill(null),
isXNext : true
}
]
const App = () => {
const [history, setHistory] = useState(NEW_GAME);
const [currentMove, setCurrentMove] = useState(0);
const current = history[currentMove];
const {winner , winningSquare} = calculateWinner(current.board);
const clickHandleFunction = (position) => {
if (current.board[position] || winner) {
return;
}
setHistory((prev) => {
const last = prev[prev.length-1];
const newBoard = last.board.map((square, pos) => {
if (pos === position) {
return last.isXNext ? 'X' : '0';
}
return square;
});
return prev.concat({board: newBoard, isXNext : !last.isXNext})
});
setCurrentMove(prev => prev +1);
};
const moveTo = (move) => {
setCurrentMove(move);
}
const onNewGame = () => {
setHistory(NEW_GAME);
setCurrentMove(0);
}
return(
<div className="app">
<h1>TIC TAC TOE</h1>
<StatusMessage winner ={winner} current ={current}/>
<Board board = {current.board} clickHandleFunction = {clickHandleFunction} winningSquare = {winningSquare}/>
<button type="button" onClick = {onNewGame}>Start New Game</button>
<History history={history} moveTo = {moveTo} currentMove = {currentMove} />
</div>
)
}
export default App;
这是我的 History.js:
import React from 'react.'
function History({history, moveTo, currentMove}) {
return (
<ul>
{
history.map((_, move) => {
return( <li key={move}> <button style={{
fontWeight: move === currentMove ? 'bold' : 'normal'
}} type="button" onClick = {moveTo(move)} >
{move === 0 ? 'Go to game start!': `Gove to move #${move}`} </button> </li> );
})
}
</ul>
)
}
export default History
答案 0 :(得分:1)
问题出在History.js
:
onClick={moveTo(move)}
您需要在 onClick
属性中提供一个函数。相反,您正在调用 moveTo
函数并将其返回值作为 onClick
属性传递。
因此,每当 React 呈现 History 组件时,它也会无意中调用 moveTo
函数,从而触发 App 组件中的更新。这就是错误所说的 - 渲染组件时无法更新另一个组件。
要解决此问题,请将 moveTo(move)
更改为 () => moveTo(move)
。现在,您将一个函数传递到 onClick
中,该函数将在用户点击时调用 moveTo
函数。工作沙箱:https://codesandbox.io/s/practical-frog-tcyxm?file=/src/components/History.js