本文实例为大家分享了js实现贪吃蛇小游戏的具体代码，供大家参考，具体内容如下
index.html
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>贪吃蛇</title> <link rel="stylesheet" href="style.css" > </head> <body> <div id="game"> <div id="explain"> <div>操作WASD 空格开始/暂停 R重新开始</div> <div>当前分数：<span id="grade">0</span>分</div> </div> <canvas id="snakegame" width="500" height="500"> </canvas> </div> <script type="text/javascript" src="/UploadFiles/2021-04-02/main.js">style.css
*{ padding: 0; margin: 0; } #game { width: 500px; margin: auto; } #explain { width: 500px; } #explain div{ width: 500px; height: 30px; } #snakegame { background: green; }main.js
/** * el 挂载的元素 * attribute 贪吃蛇的属性 */ class Game { constructor (el, attribute) { this.el = document.getElementById(el); // 获取画布的宽高 this.el.elW = parseInt(window.getComputedStyle(this.el).width); this.el.elH = parseInt(window.getComputedStyle(this.el).height); this.init(attribute); this.keyListening(); } // 初始化 init(attribute) { this.attribute = { color: "red", // 颜色 direction: "rigth", // 移动方向 state: "pause", // 状态 run pause end grade: 0, // 分数 body: [{x: 20, y: 0}, {x: 0, y: 0}], // 贪吃蛇身体 wh: 20, // 矩形的宽高 speed: 200 // 速度 }; if (attribute) { this.newAttribute = attribute; Object.keys(attribute).forEach(key => { this.attribute[key] = attribute[key]; }); } this.food ={ x: 0, y: 0, color: 'red' } this.draw(); this.foodDraw(); } // 绘制贪吃蛇 draw() { let el = this.el; let { body, wh, color } = this.attribute; // 确定浏览器是否支持canvans元素 if (el.getContext) { let context = snakegame.getContext("2d"); context.fillStyle = color; body.forEach( key => { context.fillRect(key.x, key.y, wh, wh); }); } } // 随机生成食物 foodDraw() { let el = this.el, wh = this.attribute.wh; this.food.x = Math.floor(Math.random()*(el.elW - wh)), this.food.y = Math.floor(Math.random()*(el.elH - wh)); while (this.isOverlap()) { this.food.x = Math.floor(Math.random()*(el.elW - wh)), this.food.y = Math.floor(Math.random()*(el.elH - wh)); } if (el.getContext) { let context = snakegame.getContext("2d"); context.fillStyle = this.food.color; context.fillRect(this.food.x, this.food.y, wh, wh); } } // 判断食物是否与贪吃蛇的身体重叠 isOverlap() { let { wh } = this.attribute; let food = this.food; let flag = false; function isIn(key, x, y) { if (key.x <= x && key.x + wh >= x && key.y <= y && key.y + wh >= y) { return true; } else { return false; } } this.attribute.body.forEach(key => { // 食物的上下左右四个点一个点在贪吃蛇的身体内就判断为重叠 if (isIn(key, food.x, food.y) || isIn(key, food.x, food.y + wh) || isIn(key, food.x + wh, food.y) || isIn(key, food.x + wh, food.y + wh)) { flag = true; } }); return flag; } // 清除图形 clear(x, y, width, height) { // 确定浏览器是否支持canvans元素 if (this.el.getContext) { let context = snakegame.getContext("2d"); context.clearRect(x, y, width, height); } } // 游戏状态更新 updateState(state) { this.attribute.state = state; if (state === "run") { this.run(); } } // 游戏线程 run() { let { body, wh, speed} = this.attribute; let time = setInterval(() => { // 判断游戏线程是否在运行 if (this.attribute.state !== 'run') { clearInterval(time); } let obj = {}; switch(this.attribute.direction) { case 'left': obj['x'] = body[0].x - wh; obj['y'] = body[0].y; break; case 'rigth': obj['x'] = body[0].x + wh; obj['y'] = body[0].y; break; case 'up': obj['x'] = body[0].x; obj['y'] = body[0].y - wh; break; case 'down': obj['x'] = body[0].x; obj['y'] = body[0].y + wh; break; } body.unshift(obj); // 判断是否吃到食物 if (this.isOverlap()) { this.clear(this.food.x, this.food.y, wh, wh); this.attribute.grade++; this.foodDraw(); this.draw(); } else { if (this.end()) { alert("游戏结束"); this.updateState('end'); clearInterval(time); } else { let item = body.pop(); this.clear(item.x, item.y, wh, wh); this.draw(); } } }, speed); } // 键盘事件监听 keyListening() { document.onkeydown = (event) => { let e = event || window.event || arguments.callee.caller.arguments[0]; if (e && e.keyCode === 87 && this.attribute.direction !== 'down') { // 按下W this.attribute.direction = 'up'; } if (e && e.keyCode === 65 && this.attribute.direction !== 'rigth') { // 按下A this.attribute.direction = 'left'; } if (e && e.keyCode === 68 && this.attribute.direction !== 'left') { // 按下D this.attribute.direction = 'rigth'; } if (e && e.keyCode === 83 && this.attribute.direction !== 'up') { // 按下W this.attribute.direction = 'down'; } if (e && e.keyCode === 32) { // 按下空格 let state; if (this.attribute.state === 'pause') { state = 'run'; } if (this.attribute.state === 'run') { state = 'pause'; } this.updateState(state); } if (e && e.keyCode === 82) { // 按下R键 this.reStart(); } } } // 是否死亡 end() { let body = [...this.attribute.body]; let obj = body.shift(); let flag = false; if (obj.x < 0 || obj.x >= this.el.elW || obj.y < 0 || obj.y >= this.el.elH) { flag = true; } body.forEach(key => { if (key.x === obj.x && key.y === obj.y) { flag = true; } }); return flag; } // 重新开始 reStart() { // 清除整个画布 this.clear(0, 0, this.el.elW, this.el.elH); // 重新开始 this.init(this.newAttribute); } } let game = new Game("snakegame", {color: "yellow"}); let grade = document.getElementById("grade"); let oldGrade = game.attribute.grade; setInterval(() => { if (oldGrade !== game.attribute.grade) { oldGrade = game.attribute.grade; grade.innerText = game.attribute.grade; } })截图
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。
