用HTML5+CSS+JavaScript庆祝国庆
中华人民共和国的国庆日是每年的10月1日。
1949年10月1日，中华人民共和国中央人民政府成立，在首都北京天安门广场举行了开国大典，中央人民政府主席毛泽东庄严宣告中华人民共和国成立，并亲手升起了第一面五星红旗。这一历史性的时刻标志着新中国的诞生。1949年12月2日，中央人民政府委员会第四次会议接受全国政协的建议，通过了《关于中华人民共和国国庆日的决议》，决定每年10月1日为中华人民共和国国庆日。
国庆日这一天，全国各地都会举行各种庆祝活动，如悬挂国旗、唱国歌、文艺演出、烟花表演等方式来庆祝这一重要节日。
现在，让我们用HTML5+CSS+JavaScript庆祝中华人民共和国的国庆日。
先看用css3画五星红旗效果：
用css3画五星红旗源码如下：
html
<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>CSS画五星红旗</title>
<style>
.flag{
width: 300px;
height: 200px;
background-color: red;
position: relative;
}
body {
display: flex;
height: 100vh; /* 页面高度 */
justify-content: center; /* 水平居中 */
align-items: center; /* 垂直居中 */
margin: 0; /* 去掉默认边距 */
}
.star{
margin: 0 0;
position: absolute;
display: block;
/* color: red; */
width: 0;
height: 0;
border-right: 100px solid transparent;
border-bottom: 70px solid yellow;/* */
border-left: 100px solid transparent;
transform: rotate(35deg);
left: 20px;
}
.star:before {
border-bottom: 80px solid yellow;
border-left: 30px solid transparent;
border-right: 30px solid transparent;
position: absolute;
height: 0;
width: 0;
top: -45px;
left: -65px;
display: block;
content: '';
transform: rotate(-35deg);
}
.star:after{
content: '';
margin: 0;
position: absolute;
display: block;
/* color: red; */
width: 0;
height: 0;
border-right: 100px solid transparent;
border-bottom: 70px solid yellow;/* */
border-left: 100px solid transparent;
transform: rotate(-70deg);
left: -107px;
top: 5px;
}
.big{
/* position: absolute; */
transform: scale(.3) rotate(35deg);
top: 10px;
left: -50px;
z-index: 3;
}
.little1{
position: absolute;
transform: scale(.1) rotate(-60deg);
top: -15px;
left: 5px;
}
.little2{
position: absolute;
transform: scale(.1) rotate(-45deg);
top: 5px;
left: 30px;
}
.little3{
position: absolute;
transform: scale(.1) rotate(35deg);
top: 33px;
left: 30px;
}
.little4{
position: absolute;
transform: scale(.1) rotate(60deg);
top: 50px;
left: 5px;
}
</style>
</head>
<body>
<div class="flag">
<div class="star big"></div>
<div class="star little1"></div>
<div class="star little2"></div>
<div class="star little3"></div>
<div class="star little4"></div>
</div>
</body>
</html>下面添加烟花效果烘托国庆气氛
先看国庆烟花效果：
国庆烟花源码如下：
html
<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>国庆烟花气氛</title>
<style>
body {
display: flex;
height: 100vh; /* 页面高度 */
justify-content: center; /* 水平居中 */
align-items: center; /* 垂直居中 */
margin: 0; /* 去掉默认边距 */
position: relative;
overflow: hidden;
background-color: #000; /* 背景设为黑色，模拟夜空 */
}
.flag {
width: 300px;
height: 200px;
background-color: red;
position: relative;
z-index: 1;
}
.star {
margin: 0 0;
position: absolute;
display: block;
width: 0;
height: 0;
border-right: 100px solid transparent;
border-bottom: 70px solid yellow;
border-left: 100px solid transparent;
transform: rotate(35deg);
left: 20px;
}
.star:before {
border-bottom: 80px solid yellow;
border-left: 30px solid transparent;
border-right: 30px solid transparent;
position: absolute;
height: 0;
width: 0;
top: -45px;
left: -65px;
display: block;
content: '';
transform: rotate(-35deg);
}
.star:after {
content: '';
margin: 0;
position: absolute;
display: block;
width: 0;
height: 0;
border-right: 100px solid transparent;
border-bottom: 70px solid yellow;
border-left: 100px solid transparent;
transform: rotate(-70deg);
left: -107px;
top: 5px;
}
.big {
transform: scale(.3) rotate(35deg);
top: 10px;
left: -50px;
z-index: 3;
}
.little1 {
position: absolute;
transform: scale(.1) rotate(-60deg);
top: -15px;
left: 5px;
}
.little2 {
position: absolute;
transform: scale(.1) rotate(-45deg);
top: 5px;
left: 30px;
}
.little3 {
position: absolute;
transform: scale(.1) rotate(35deg);
top: 33px;
left: 30px;
}
.little4 {
position: absolute;
transform: scale(.1) rotate(60deg);
top: 50px;
left: 5px;
}
canvas {
position: absolute;
top: 0;
left: 0;
width: 100%;
height: 100%;
pointer-events: none; /* 使canvas不会阻止点击事件 */
}
</style>
</head>
<body>
<canvas id="fireworks"></canvas>
<div class="flag">
<div class="star big"></div>
<div class="star little1"></div>
<div class="star little2"></div>
<div class="star little3"></div>
<div class="star little4"></div>
</div>
<script>
const canvas = document.getElementById('fireworks');
const ctx = canvas.getContext('2d');
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
function randomColor() {
return `hsl(${Math.random() * 360}, 100%, 50%)`;
}
function Firework(x, y) {
this.x = x;
this.y = y;
this.size = Math.random() * 10 + 5;
this.speed = Math.random() * 6 + 2;
this.angle = Math.random() * Math.PI * 2;
this.color = randomColor();
this.exploded = false;
this.particles = [];
this.update = function () {
if (!this.exploded) {
this.y -= this.speed;
// 限制烟花的最大高度
if (this.y < canvas.height * 0.2) { // 高度限制
this.exploded = true;
this.createParticles();
}
if (this.size > 0) {
this.size -= 0.1;
} else {
this.exploded = true;
this.createParticles();
}
} else {
this.particles.forEach(p => p.update());
}
};
this.createParticles = function () {
const particleCount = Math.random() * 100 + 50;
for (let i = 0; i < particleCount; i++) {
this.particles.push(new Particle(this.x, this.y, this.color));
}
};
this.draw = function () {
if (!this.exploded) {
if (this.size > 0) { // 仅在大小为正时绘制。
ctx.fillStyle = this.color;
ctx.beginPath();
ctx.arc(this.x, this.y, this.size, 0, Math.PI * 2);
ctx.fill();
}
} else {
this.particles.forEach(p => p.draw());
}
};
}
function Particle(x, y, color) {
this.x = x;
this.y = y;
// 将颜色分解为RGB，以便后续使用
this.color = color.match(/\d+/g).map(Number);
this.size = Math.random() * 3 + 2;
this.speed = Math.random() * 3 + 1;
this.angle = Math.random() * Math.PI * 2;
this.alpha = 1;
this.update = function () {
this.x += Math.cos(this.angle) * this.speed;
this.y += Math.sin(this.angle) * this.speed;
this.alpha -= 0.02;
};
this.draw = function () {
ctx.fillStyle = `rgba(${this.color.join(",")}, ${this.alpha})`;
if (this.alpha > 0) { // 仅当透明度为正时绘制。
ctx.beginPath();
ctx.arc(this.x, this.y, this.size, 0, Math.PI * 2);
ctx.fill();
}
};
}
const fireworks = [];
function createFirework() {
const firework = new Firework(Math.random() * canvas.width, canvas.height);
fireworks.push(firework);
}
function animate() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
fireworks.forEach((firework, index) => {
firework.update();
firework.draw();
if (firework.exploded && firework.particles.length === 0) {
fireworks.splice(index, 1);
}
});
requestAnimationFrame(animate);
}
for (let i = 0; i < 5; i++) {
createFirework();
}
animate();
setInterval(createFirework, 1000);
</script>
</body>
</html>