Das Beispiel in diesem Artikel teilt den relevanten Code des js Snake-Spiels als Referenz. Der spezifische Inhalt ist wie folgt
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>贪吃蛇小游戏</title>
<style>
*{margin:0; padding:0;}
header {
display: block;
margin: 0 auto;
width: 500px;
text-align: center;
}
header h1 {
font-family: Arial;
font-weight: bold;
}
header #newGameButton {
display: block;
margin: 20px auto;
width: 100px;
padding: 10px 10px;
background-color: #8f7a66;
font-family: Arial;
color: white;
border-radius: 10px;
text-decoration: none;
}
header #newGameButton:hover {
background-color: #9f8b77;
}
header p {
font-family: Arial;
font-size: 25px;
margin: 20px auto;
}
canvas{
display:block;
border:medium double black;
margin:4px auto;
}
</style>
</head>
<body>
<header>
<h1>贪吃蛇小游戏</h1>
<a href="javascript:newgame();" id="newGameButton">New Game</a>
<p>score:<span id="score">0</span></p>
</header>
<canvas id="canvas">
Your browser doesn't support the <code>canvas</code> element.
</canvas>
<script>
var CANVAS = document.getElementById("canvas");
var CTX = CANVAS.getContext("2d");
var SNAKE = new Array(); //用队列模拟蛇身
var DIR = "right"; //用来控制蛇头的方向
var SIZE = 20; //蛇身的宽度
var FOODX = 0; //食物的x坐标
var FOODY = 0; //食物的y坐标
var HEADX = 0; //蛇头的x坐标
var HEADY = 0; //蛇头的y坐标
var MAXWIDTH = 200; //画布的高度
var MAXHEIGHT = 200; //画布的宽度
var TIME = 400; //蛇的速度
var SCORE = 0; //计算玩家分数
var interval = null;
CANVAS.width = MAXWIDTH;
CANVAS.height = MAXHEIGHT;
window.onload = function(){
newgame();
};
document.getElementById("newGameButton").click(function(){
newgame();
});
function newgame(){
SNAKE = []; //用队列模拟蛇身
DIR = "right"; //用来控制蛇头的方向
HEADX = 0; //蛇头的x坐标
HEADY = 0; //蛇头的y坐标
SCORE = 0;
window.clearInterval(interval);
interval = null;
//初始化画布
CTX.clearRect(0, 0, MAXWIDTH, MAXHEIGHT);
//画一条蛇
drawSnake();
//放置食物
setFood();
//移动蛇
interval = window.setInterval(move, TIME);
}
function move(){
switch(DIR){
case "up":HEADY = HEADY-SIZE;break;
case "right":HEADX = HEADX+SIZE;break;
case "down":HEADY = HEADY+SIZE;break;
case "left":HEADX = HEADX-SIZE;break;
}
if(HEADX>MAXWIDTH-SIZE || HEADY>MAXHEIGHT-SIZE || HEADX<0 || HEADY<0){
alert("你的分数为："+SCORE+"分，继续努力吧!失败原因：碰壁了.....");
window.location.reload();
}
for(var i=1;i<SNAKE.length;i++){
if(SNAKE[i][0] == SNAKE[0][0] && SNAKE[i][1] == SNAKE[0][1]){
alert("你的分数为："+SCORE+"分，继续努力吧！失败原因：撞到自己了.....");
window.location.reload();
}
}
if(SNAKE.length == MAXWIDTH *MAXHEIGHT){
alert("好厉害!么么哒~");
window.location.reload();
}
moveIn(HEADX, HEADY);//移动一格
}
document.onkeydown = function(e) { //改变蛇方向
var code = e.keyCode - 37;
switch(code){
case 1 : DIR = "up";break;//上
case 2 : DIR = "right";break;//右
case 3 : DIR = "down";break;//下
case 0 : DIR = "left";break;//左
}
}
//=============================画一条蛇=======================================================
function drawSnake(){
CTX.fillStyle = "black";
//画蛇头
CTX.fillRect (HEADX, HEADY, SIZE, SIZE);
SNAKE.push([HEADX, HEADY]);
//画蛇身
switch(DIR){
case "up":
drawBody(HEADX, HEADY + SIZE, HEADX, HEADY + 2 * SIZE);
break;
case "right":
drawBody(HEADX - SIZE, HEADY, HEADX - 2 * SIZE, HEADY);
break;
case "down":
drawBody(HEADX, HEADY - SIZE, HEADX, HEADY - 2 * SIZE);
break;
case "left":
drawBody(HEADX + SIZE, HEADY, HEADX + 2 * SIZE, HEADY);
break;
}
}
function drawBody(x1, y1, x2, y2){
CTX.fillRect (x1, y1, SIZE, SIZE);
CTX.fillRect (x2, y2, SIZE, SIZE);
SNAKE.push([x1, y1]);
SNAKE.push([x2, y2]);
}
//===========================放置食物==============================
function setFood(){
do{
FOODX = SIZE * Math.floor(Math.random() * MAXWIDTH / SIZE);
FOODY = SIZE * Math.floor(Math.random() * MAXHEIGHT / SIZE);
}while(foodInSnake());
CTX.fillStyle = "red";
CTX.fillRect (FOODX, FOODY, SIZE, SIZE);
}
function foodInSnake(){
for (var i = 0; i < SNAKE.length; i++) {
if(FOODX == SNAKE[i][0] && FOODY == SNAKE[i][1]){
return true;
}
}
return false;
}
//========================================移动一格===========================
function moveIn(x, y){
CTX.fillStyle = "black";
CTX.fillRect(x, y, SIZE, SIZE);//重画蛇头
//把新蛇头添加到 SNAKE 数组
var newSnake = [[x, y]];
SNAKE = newSnake.concat(SNAKE);
if(false == eatFood()){//如果没吃到食物，减少一格蛇尾
var snakeTail = SNAKE.pop();//获得蛇尾位置
CTX.clearRect(snakeTail[0], snakeTail[1], SIZE, SIZE);//去掉蛇尾
}
}
function eatFood(){
if(HEADX == FOODX && HEADY == FOODY){
CTX.fillStyle = "block";
CTX.fillRect (FOODX, FOODY, SIZE, SIZE);
setFood();
SCORE++;
//$("#score").text(SCORE);
document.getElementById("score").innerHTML = SCORE;
return true;
}
return false;
}
</script>
</html>
Rendering:
Dinge:
function newgame(){
重置蛇和分数的数据；
清除interval；
初始化画布；
画一条蛇；
放置食物；
使用定时器（setInterval）使蛇移动（move函数）；
}
function move(){
根据方向改变蛇头下一格将要到达的位置；
判断游戏是否结束，以及显示结束的原因（包含输赢）；
蛇移动一格（moveIn函数）；
}
对键盘的方向键作监控，当改变方向时，修改全局变量DIR的值（用于存储方向）；
function moveIn(){
在蛇头的前一格增加一格作为新的蛇头，并将蛇头的坐标作为第一个元素加入到代表蛇的数组中；
if(没吃到食物){
删除一格蛇尾，在画布中做相应改变；
}
}
Es ist zu beachten, dass sich das Festlegen der Breite und Höhe der Leinwand in JS geringfügig vom Festlegen anderer CSS-Eigenschaften unterscheidet.
CANVAS.width = MAXWIDTH;CANVAS.height = MAXHEIGHT; Der Herausgeber hat außerdem spannende Themen für Sie vorbereitet:
Eine Zusammenfassung klassischer JavaScript-Spiele Das Obige ist der gesamte Inhalt dieses Artikels. Ich hoffe, dass er für alle beim Erlernen der Javascript-Programmierung hilfreich sein wird.
