ReactJS - 02 - ReactJS之入门之00之示例
程序员文章站
2022-06-17 09:08:19
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认识一个事物，最直接最感性的认识莫过于直截了当的拿过来看看是什么样子。
二话不说，直接看看 ReactJS DEMO 中的例子吧！
一、官网文档：
https://reactjs.org/tutorial/tutorial.html#completing-the-game
Throughout this tutorial, we touched on React concepts including elements, components, props, and state.
Next 1:
For a more detailed explanation of each of these topics, check out the rest of the documentation.
Next 2:
To learn more about defining components, check out the React.Component API reference.
二、在线运行：
http://www.runoob.com/try/try.php?filename=try_react_component
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二话不说，直接看看 ReactJS DEMO 中的例子吧！
一、官网文档：
https://reactjs.org/tutorial/tutorial.html#completing-the-game
Throughout this tutorial, we touched on React concepts including elements, components, props, and state.
Next 1:
For a more detailed explanation of each of these topics, check out the rest of the documentation.
Next 2:
To learn more about defining components, check out the React.Component API reference.
二、在线运行：
http://www.runoob.com/try/try.php?filename=try_react_component
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<title>菜鸟教程 React 实例</title>
<script src="https://cdn.bootcss.com/react/16.4.0/umd/react.development.js"></script>
<script src="https://cdn.bootcss.com/react-dom/16.4.0/umd/react-dom.development.js"></script>
<script src="https://cdn.bootcss.com/babel-standalone/6.26.0/babel.min.js"></script>
<style>
body {
font: 14px "Century Gothic", Futura, sans-serif;
margin: 20px;
}
ol, ul {
padding-left: 30px;
}
.board-row:after {
clear: both;
content: "";
display: table;
}
.status {
margin-bottom: 10px;
}
.square {
background: #fff;
border: 1px solid #999;
float: left;
font-size: 24px;
font-weight: bold;
line-height: 34px;
height: 34px;
margin-right: -1px;
margin-top: -1px;
padding: 0;
text-align: center;
width: 34px;
box-sizing: border-box;
display: inline-block;
}
.square:focus {
outline: none;
}
.kbd-navigation .square:focus {
background: #ddd;
}
.game {
display: flex;
flex-direction: row;
}
.game-info {
margin-left: 20px;
}
</style>
</head>
<body>
<div id="example"></div>
<script type="text/babel">
function Square(props) {
return (
<span>
<button className="square" onClick={props.onClick}>
{props.value}
</button>
<div className="square" onClick={props.onClick}>
{props.value}
</div>
<i className="square" onClick={props.onClick}>
{props.value}
</i>
<span className="square" onClick={props.onClick}>
{props.value}
</span>
</span>
);
}
class Board extends React.Component {
renderSquare(i) {
return (
<Square value={this.props.squares[i]}
onClick={() => this.props.onClick(i)}
/>
);
}
render() {
return (
<div>
<div className="board-row">
{this.renderSquare(0)}
{this.renderSquare(1)}
{this.renderSquare(2)}
</div>
<div className="board-row">
{this.renderSquare(3)}
{this.renderSquare(4)}
{this.renderSquare(5)}
</div>
<div className="board-row">
{this.renderSquare(6)}
{this.renderSquare(7)}
{this.renderSquare(8)}
</div>
</div>
);
}
}
class Game extends React.Component {
constructor(props) {
super(props);
this.state = {
history: [{
squares: Array(9).fill(null),
}],
stepNumber: 0,
xIsNext: true,
};
}
handleClick(i) {
const history = this.state.history.slice(0, this.state.stepNumber + 1);
const current = history[history.length - 1];
const squares = current.squares.slice();
if (calculateWinner(squares) || squares[i]) {
return;
}
squares[i] = this.state.xIsNext ? 'X' : 'O';
this.setState({
history: history.concat([{
squares: squares,
}]),
xIsNext: !this.state.xIsNext,
stepNumber: history.length
});
}
jumpTo(step) {
this.setState({
stepNumber: step,
xIsNext: (step % 2) === 0
});
}
render() {
const history = this.state.history;
const current = history[this.state.stepNumber];
const winner = calculateWinner(current.squares);
let status;
if (winner) {
status = 'Winner: ' + winner;
} else {
status = 'Next player: ' + (this.state.xIsNext ? 'X' : 'O');
}
const moves = history.map((item, indexStep) => {
const desc =
indexStep ?
'Go to move #' + indexStep :
'Go to game start';
return (
<li key={indexStep}>
<button onClick={() => this.jumpTo(indexStep)}>{desc}</button>
</li>
);
});
return (
<div className="game">
<div className="game-board">
<Board
squares={current.squares}
onClick={(i) => this.handleClick(i)}
/>
</div>
<div className="game-info">
<div>{status}</div>
<ol>{moves}</ol>
</div>
</div>
);
}
}
// ========================================
ReactDOM.render(
<Game />,
document.getElementById('example')
);
function calculateWinner (squares) {
const lines = [
[0, 1, 2],
[3, 4, 5],
[6, 7, 8],
[0, 3, 6],
[1, 4, 7],
[2, 5, 8],
[0, 4, 8],
[2, 4, 6],
];
for (let i = 0; i < lines.length; i++) {
const [a, b, c] = lines[i];
if (squares[a] && squares[a] === squares[b] && squares[a] === squares[c]) {
return squares[a];
}
}
return null;
}
</script>
</body>
</html>
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