HTML5動(dòng)畫背景代碼是一種使用HTML5技術(shù)制作的動(dòng)畫效果，可以作為網(wǎng)頁的背景來增加視覺沖擊力和美感。下面是一個(gè)HTML5動(dòng)畫背景代碼的示例：
<!DOCTYPE html>
<html>
<head>
<style>
body {
margin: 0;
padding: 0;
overflow: hidden;
}
canvas {
display: block;
}
</style>
</head>
<body>
<canvas id="canvas" />
<script>
var canvas = document.getElementById('canvas');
var ctx = canvas.getContext('2d');
var width = window.innerWidth;
var height = window.innerHeight;
canvas.width = width;
canvas.height = height;
var particles = [];
for (var i = 0; i < 100; i++) {
particles.push({
x: Math.random() * width,
y: Math.random() * height,
radius: Math.random() * 4,
color: '#FFF',
speedX: Math.random() * 3 - 1.5,
speedY: Math.random() * 3 - 1.5
});
}
function loop() {
requestAnimationFrame(loop);
ctx.clearRect(0, 0, width, height);
particles.forEach(function(particle) {
particle.x += particle.speedX;
particle.y += particle.speedY;
if (particle.x > width) {
particle.x = 0;
} else if (particle.x < 0) {
particle.x = width;
}
if (particle.y > height) {
particle.y = 0;
} else if (particle.y < 0) {
particle.y = height;
}
ctx.beginPath();
ctx.arc(particle.x, particle.y, particle.radius, 0, 2 * Math.PI);
ctx.fillStyle = particle.color;
ctx.fill();
});
}
loop();
</script>
</body>
</html>上面的代碼使用了<canvas>標(biāo)簽來繪制動(dòng)畫背景，利用了<script>標(biāo)簽內(nèi)的JavaScript代碼來控制粒子的移動(dòng)、顏色等屬性。對(duì)于需要添加動(dòng)畫背景的網(wǎng)頁，只需將上面的代碼復(fù)制粘貼到<body>標(biāo)簽內(nèi)即可。