效果图：
代码：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>幸运大转盘</title>
<style>
* {
margin: 0;
padding: 0;
box-sizing: border-box;
}
body {
font-family: 'Arial', sans-serif;
background-color: #e0f7fa;
/* 轻松的浅蓝色背景 */
display: flex;
justify-content: center;
align-items: center;
height: 100vh;
color: #333;
}
.container {
text-align: center;
}
h1 {
font-size: 32px;
color: #00796b;
margin-bottom: 20px;
}
.wheel-container {
position: relative;
margin: 0 auto;
}
canvas {
border: 10px solid #00796b;
border-radius: 50%;
box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}
/* 指针样式 */
.pointer {
position: absolute;
top: 235px;
/* 调整指针位置 */
left: 100%;
transform: translateX(-50%)rotate(-90deg);
width: 0;
height: 0;
border-left: 20px solid transparent;
border-right: 20px solid transparent;
border-bottom: 40px solid #d32f2f;
/* 红色指针 */
z-index: 10;
}
button {
margin-top: 30px;
padding: 15px 30px;
font-size: 20px;
background-color: #00796b;
color: white;
border: none;
cursor: pointer;
border-radius: 5px;
box-shadow: 0 5px 10px rgba(0, 0, 0, 0.1);
transition: background-color 0.3s ease;
}
button:hover {
background-color: #004d40;
}
button:active {
background-color: #00251a;
}
</style>
</head>
<body>
<div class="container">
<h1>幸运大转盘</h1>
<div class="wheel-container">
<div class="pointer"></div> <!-- 添加指针 -->
<canvas id="wheelCanvas" width="500" height="500"></canvas>
</div>
<button id="spinBtn">开始抽奖</button>
</div>
<script>
const wheelCanvas = document.getElementById("wheelCanvas");
const ctx = wheelCanvas.getContext("2d");
const spinBtn = document.getElementById("spinBtn");
// 奖品数组和颜色
const segments = ["二组", "三组", "四组", "五组", "七组"];
const segmentColors = ["#FF6B6B", "#FFD93D", "#6BCB77", "#4D96FF", "#C34A36"];
const numSegments = segments.length;
const anglePerSegment = (2 * Math.PI) / numSegments; // 每个奖品占据的角度
let currentAngle = 0; // 当前旋转的总角度
let spinning = false;
let animationFrame;
let maxRotationTime = 5000; // 最大旋转时间，单位为毫秒
let stopSpinningTimeout;
// 绘制转盘
function drawWheel() {
ctx.clearRect(0, 0, wheelCanvas.width, wheelCanvas.height);
for (let i = 0; i < numSegments; i++) {
const angle = currentAngle + i * anglePerSegment;
ctx.beginPath();
ctx.moveTo(250, 250);
ctx.arc(250, 250, 250, angle, angle + anglePerSegment);
ctx.fillStyle = segmentColors[i];
ctx.fill();
ctx.save();
// 绘制奖品名称
ctx.translate(250, 250);
ctx.rotate(angle + anglePerSegment / 2);
ctx.textAlign = "center";
ctx.fillStyle = "#FFF";
ctx.font = "bold 20px Arial";
ctx.fillText(segments[i], 150, 10);
ctx.restore();
}
}
// 平滑旋转效果
let maxSpeed = 0;
let currentSpeed = 0;
let deceleration = 0.0002; // 每帧减速量
// 开始旋转转盘
function spinWheel() {
if (!spinning) {
spinning = true;
currentSpeed = Math.random() * 0.3 + 0.2; // 随机最大速度
requestAnimationFrame(rotateWheel);
// 设置在最大旋转时间后开始减速
stopSpinningTimeout = setTimeout(() => {
startDecelerating();
}, maxRotationTime);
}
}
// 开始减速
function startDecelerating() {
deceleration = 0.002; // 设置一个合理的减速值
}
// 动态旋转转盘
function rotateWheel() {
if (!spinning) return;
if (currentSpeed > 0) {
currentAngle += currentSpeed; // 增加旋转角度
currentSpeed -= deceleration; // 逐渐减速
if (currentSpeed < 0) currentSpeed = 0; // 防止负速度
}
drawWheel(); // 每次旋转时重新绘制转盘
currentAngle = currentAngle % (2 * Math.PI); // 确保角度不超过 360 度
if (currentSpeed > 0) {
animationFrame = requestAnimationFrame(rotateWheel);
} else {
spinning = false;
cancelAnimationFrame(animationFrame);
clearTimeout(stopSpinningTimeout);
calculateResult();
}
}
// 计算中奖结果
function calculateResult() {
// 获取最终停止时的角度，并确定指针指向的奖品
const finalAngle = (2 * Math.PI - currentAngle) % (2 * Math.PI);
const segmentIndex = Math.floor(finalAngle / anglePerSegment);
alert(`本次大转盘抽取到: ${segments[segmentIndex]}!`);
}
// 绑定按钮事件
spinBtn.addEventListener("click", spinWheel);
// 初次绘制转盘
drawWheel();
</script>
</body>
</html>