1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154
| import React from 'react'; import ReactDOM from 'react-dom'; import './index.css';
function Square(props) { return (<button className='square' style={{ color: props.highlight ? 'red' : '' }} onClick={props.onClick}>{props.value}</button>) }
class Board extends React.Component { constructor(props) { super(props); this.state = { squares: Array(9).fill(null), xIsNext: true, line: null } }
renderSquare(i) { return <Square highlight={this.props.line?.includes(i)} key={i} value={this.props.squares[i]} onClick={() => this.props.onClick(i)} />; }
render() { let index = 0 return ( <div> {[1, 2, 3].map(i => ( <div key={i} className='board-row'> {Array(3).fill(null).map(() => this.renderSquare(index++))} </div> ))} </div>); } }
class Game extends React.Component { constructor(props) { super(props); this.state = { history: [{ squares: Array(9).fill(null), index: null }], stepNumber: 0, xIsNext: true, historyIsDesc: false } }
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).winner || squares[i]) { return } squares[i] = this.state.xIsNext ? 'X' : 'O' let row = i + 1; let cell = 1; while (row > 3) { row -= 3; cell++; }
this.setState({ history: history.concat([{ squares, index: { row, cell } }]), stepNumber: history.length, xIsNext: !this.state.xIsNext }) }
changeHistoryOrderBy() { this.setState({ ...this.state, historyIsDesc: !this.state.historyIsDesc }) }
jumpTo(stepNumber) { this.setState({ stepNumber, xIsNext: (stepNumber % 2) === 0 }) }
render() { const history = this.state.history; const current = history[this.state.stepNumber]; const { winner, line } = calculateWinner(current.squares); let historyIsDesc = this.state.historyIsDesc;
const moves = history.map((step, move) => {
const desc = move ? `Go to move #${move} (${step.index.row},${step.index.cell})` : 'Go to game start'; return ( <li key={move}> {/* 2.在历史记录列表中加粗显示当前选择的项目。 */} <button style={{ fontWeight: this.state.stepNumber == move ? 'bold' : '' }} onClick={() => this.jumpTo(move)}>{desc}</button> </li> ) })
let status; if (winner) { status = 'Winner: ' + winner; } else { if (this.state.stepNumber < 9) { status = 'Next player: ' + (this.state.xIsNext ? 'X' : 'O'); } else { status = 'Draw!'; } }
return ( <div className="game"> <div className="game-board"> <Board line={line} squares={current.squares} onClick={(i) => this.handleClick(i)} /> </div> <div className="game-info"> <div>{status}</div> {/* 4.添加一个可以升序或降序显示历史记录的按钮。 */} <button onClick={() => this.changeHistoryOrderBy()}>{`切换为${historyIsDesc ? '升' : '降'}序显示历史记录`}</button> <ol>{historyIsDesc ? moves.reverse() : moves}</ol> </div> </div> ); } }
ReactDOM.render( <Game />, document.getElementById('root') );
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 { winner: squares[a], line: [a, b, c] }; } } return {}; }
|