我最近做了这个游戏，想问一下如何改进它。我在javascript中制作了一个警报框，用于游戏何时结束。它有效，但并不美丽。所以我想问如何更改警报框顶部的颜色和消息？现在已经写了一个网页消息。 我想补充一点，它可以从手机上播放，就像箭头按钮一样。我为java找到了一些东西，但没有为javascript找到任何东西，并想知道它是否可能以及我该怎么做？ 这是代码：
<html>
<head>
<meta charset='utf-8'/>
<link rel="stylesheet" href="css/style.css">
<h1> <p align="left"><font color="rebeccapurple"> Snake developed by agente00mcm </font></p> </h1>
</head>
<body>
<div class= 'game'>
<div id = 'home'>
<canvas id='mycanvas' width='800' height='800'>
</canvas>
</div>
<p>Press start to start the game!</p>
<button id='btn'>START</button>
</div>
<script>
var mycanvas = document.getElementById('mycanvas');
var ctx = mycanvas.getContext('2d');
var snakeSize = 10;
var w = 800;
var h = 800;
var score = 0;
var snake;
var snakeSize = 10;
var food;
var drawModule = (function () {
var bodySnake = function(x, y) {
ctx.fillStyle = 'green';
ctx.fillRect(x*snakeSize, y*snakeSize, snakeSize, snakeSize);
ctx.strokeStyle = 'darkgreen';
ctx.strokeRect(x*snakeSize, y*snakeSize, snakeSize, snakeSize);
}
var pizza = function(x, y) {
ctx.fillStyle = 'yellow';
ctx.fillRect(x*snakeSize, y*snakeSize, snakeSize, snakeSize);
ctx.fillStyle = 'red';
ctx.fillRect(x*snakeSize+1, y*snakeSize+1, snakeSize-2, snakeSize-2);
}
var scoreText = function() {
var score_text = "Score: " + score;
ctx.fillStyle = 'blue';
ctx.fillText(score_text, 145, h-5);
}
var drawSnake = function() {
var length = 4;
snake = [];
for (var i = length-1; i>=0; i--) {
snake.push({x:i, y:0});
}
}
var paint = function(){
ctx.fillStyle = 'lightgray';
ctx.fillRect(0, 0, w, h);
ctx.strokeStyle = 'black';
ctx.strokeRect(0, 0, w, h);
btn.setAttribute('disabled', true);
var snakeX = snake[0].x;
var snakeY = snake[0].y;
if (direction == 'right') {
snakeX++; }
else if (direction == 'left') {
snakeX--; }
else if (direction == 'up') {
snakeY--;
} else if(direction == 'down') {
snakeY++; }
if (snakeX == -1 || snakeX == w/snakeSize || snakeY == -1 || snakeY == h/snakeSize || checkCollision(snakeX, snakeY, snake)) {
//restart game
alert("Game Over nYour Score: "+score);
document.location.reload();
btn.removeAttribute('disabled', true);
ctx.clearRect(0,0,w,h);
gameloop = clearInterval(gameloop);
return;
}
if(snakeX == food.x && snakeY == food.y) {
var tail = {x: snakeX, y: snakeY}; //Create a new head instead of moving the tail
score ++;
createFood(); //Create new food
} else {
var tail = snake.pop(); //pops out the last cell
tail.x = snakeX;
tail.y = snakeY;
}
//The snake can now eat the food.
snake.unshift(tail); //puts back the tail as the first cell
for(var i = 0; i < snake.length; i++) {
bodySnake(snake[i].x, snake[i].y);
}
pizza(food.x, food.y);
scoreText();
}
var createFood = function() {
food = {
x: Math.floor((Math.random() * 30) + 1),
y: Math.floor((Math.random() * 30) + 1)
}
for (var i=0; i>snake.length; i++) {
var snakeX = snake[i].x;
var snakeY = snake[i].y;
if (food.x===snakeX && food.y === snakeY || food.y === snakeY && food.x===snakeX) {
food.x = Math.floor((Math.random() * 30) + 1);
food.y = Math.floor((Math.random() * 30) + 1);
}
}
}
var checkCollision = function(x, y, array) {
for(var i = 0; i < array.length; i++) {
if(array[i].x === x && array[i].y === y)
return true;
}
return false;
}
var init = function(){
direction = 'down';
drawSnake();
createFood();
gameloop = setInterval(paint, 80);
}
return {
init : init
};
}());
(function (window, document, drawModule, undefined) {
var btn = document.getElementById('btn');
btn.addEventListener("click", function(){ drawModule.init();});
document.onkeydown = function(event) {
keyCode = window.event.keyCode;
keyCode = event.keyCode;
switch(keyCode) {
case 37:
if (direction != 'right') {
direction = 'left';
}
console.log('left');
break;
case 39:
if (direction != 'left') {
direction = 'right';
console.log('right');
}
break;
case 38:
if (direction != 'down') {
direction = 'up';
console.log('up');
}
break;
case 40:
if (direction != 'up') {
direction = 'down';
console.log('down');
}
break;
}
}
})(window, document, drawModule);
</script>
</body>
</html>警告框是一个系统对象，不能使用 css 设置样式。如果要设置警报的样式，则需要在页面中创建一个元素，该元素复制警报的行为。您可以找到许多执行此操作的库，例如：
- 甜蜜警报
- jQueryUi 对话框
- AlertifyJs
:)开发游戏时玩得开心