要使用 CSS 在图像背景上实现波纹效果,可以使用 HTML5 的 <canvas>
元素结合 CSS 进行操作。下面是一个简单的例子,展示了如何使用 CSS 和 JavaScript 创建一个具有波纹效果的图像背景:
<canvas>
元素,并为其设置 CSS 样式:<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>波纹效果示例</title>
<style>
body, html {
margin: 0;
padding: 0;
height: 100%;
overflow: hidden;
}
#canvas {
position: absolute;
top: 0;
left: 0;
z-index: -1;
}
.content {
position: relative;
z-index: 1;
text-align: center;
color: white;
font-size: 2rem;
padding: 20px;
}
</style>
</head>
<body>
<canvas id="canvas"></canvas>
<div class="content">
<h1>波纹效果示例</h1>
</div>
<script src="script.js"></script>
</body>
</html>
script.js
)中编写波纹效果的动画:const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
const width = canvas.width = window.innerWidth;
const height = canvas.height = window.innerHeight;
class Ripple {
constructor(x, y) {
this.x = x;
this.y = y;
this.size = 0;
this.maxSize = Math.max(width, height) / 4;
this.speed = 5; // 控制波纹扩散速度
}
update() {
this.size += this.speed;
if (this.size > this.maxSize) {
this.size = 0;
}
}
draw(ctx) {
ctx.beginPath();
ctx.arc(this.x, this.y, this.size, 0, Math.PI * 2);
ctx.strokeStyle = `rgba(255, 255, 255, ${1 - this.size / this.maxSize})`;
ctx.lineWidth = 2;
ctx.stroke();
}
}
const ripples = [];
function createRipple(e) {
const rect = canvas.getBoundingClientRect();
const x = e.clientX - rect.left;
const y = e.clientY - rect.top;
ripples.push(new Ripple(x, y));
}
function animate() {
ctx.clearRect(0, 0, width, height);
ripples.forEach((ripple, index) => {
ripple.update();
ripple.draw(ctx);
if (ripple.size === 0) {
ripples.splice(index, 1);
}
});
requestAnimationFrame(animate);
}
animate();
canvas.addEventListener('click', createRipple);
window.addEventListener('resize', () => {
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
});
<body>
或其他元素的背景,确保 <canvas>
元素位于图像之上,并且 z-index 值比图像元素低。注意:此示例中,波纹效果将仅在用户点击画布时产生。您可以根据需要调整代码来创建其他触发波纹效果的事件,如鼠标移动等。
现在运行此示例,您应该能看到一个具有波纹效果的图像背景。您可以根据需要调整 CSS 和 JavaScript 代码以适应您的需求。
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