Pen Settings

HTML

CSS

CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URLs added here will be added as <link>s in order, and before the CSS in the editor. You can use the CSS from another Pen by using its URL and the proper URL extension.

+ add another resource

JavaScript

Babel includes JSX processing.

Add External Scripts/Pens

Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

+ add another resource

Packages

Add Packages

Search for and use JavaScript packages from npm here. By selecting a package, an import statement will be added to the top of the JavaScript editor for this package.

Behavior

Auto Save

If active, Pens will autosave every 30 seconds after being saved once.

Auto-Updating Preview

If enabled, the preview panel updates automatically as you code. If disabled, use the "Run" button to update.

Format on Save

If enabled, your code will be formatted when you actively save your Pen. Note: your code becomes un-folded during formatting.

Editor Settings

Code Indentation

Want to change your Syntax Highlighting theme, Fonts and more?

Visit your global Editor Settings.

HTML

              
                <div class="container">
	<div id="turntable" class="turntable"></div>
	<div class="arrow"></div>
	<div id="lottery-btn" class="lottery-btn">抽奖</div>
</div>
              
            
!

CSS

              
                .container {
	width: 500px;
	padding: 40px;
	background: #f8fafc;
	display: flex;
	justify-content: center;
}

.turntable {
	position: relative;
	width: 400px;
	height: 400px;
	border-radius: 50%;
}

.prize-label {
	position: absolute;
	width: 100%;
	height: 100%;
	display: flex;
	justify-content: center;
	align-items: baseline;
	font-weight: bold;
	color: white;
	line-height: 100px;
}

.arrow {
	position: absolute;
	top: 140px;
	width: 0;
	height: 0;
	border-left: 15px solid transparent;
	border-right: 15px solid transparent;
	border-bottom: 100px solid #f8fafc;
}

.lottery-btn {
	position: absolute;
	top: 200px;
	width: 80px;
	height: 80px;
	border-radius: 50%;
	background: #f8fafc;
	display: flex;
	justify-content: center;
	align-items: center;
	color: #333;
	font-weight: bold;
	cursor: pointer;
	user-select: none;

	&--disabled {
		color: #999;
		pointer-events: none;
	}
}

              
            
!

JS

              
                interface Prize {
	label: string;
	probability: number;
	bgColor: string;
}

const prizes: Prize[] = [
	{ label: "超级大奖", probability: 0.001, bgColor: "#b91c1c" },
	{ label: "特等奖", probability: 0.009, bgColor: "#c2410c" },
	{ label: "一等奖", probability: 0.01, bgColor: "#7e22ce" },
	{ label: "二等奖", probability: 0.03, bgColor: "#2563eb" },
	{ label: "三等奖", probability: 0.15, bgColor: "#15803d" },
	{ label: "安慰奖", probability: 0.3, bgColor: "#1e293b" },
	{ label: "谢谢参与", probability: 0.5, bgColor: "#3f3f46" }
];

const turntableDom = document.getElementById("turntable");
const lotteryBtnDom = document.getElementById("lottery-btn");

const proportionPerPrize = Number((100 / prizes.length).toFixed(1));
const anglePerPrize = Number((360 / prizes.length).toFixed(1));

const animationDuration = 5000;
const rotateLapsBase = 10;
let rotateLaps = 0;

// #region 划分转盘扇形区域
const turntableConicGradient = prizes.map((prize, index) => {
	const from = (proportionPerPrize * index).toFixed(1);
	const to =
		index === prizes.length - 1
			? 100
			: (proportionPerPrize * (index + 1)).toFixed(1);
	return `${prize.bgColor} ${from}% ${to}%`;
});
turntableDom.style.background = `conic-gradient(${turntableConicGradient.join(
	","
)})`;
// #endregion

// #region 添加奖品名节点
const prizeLabels = document.createDocumentFragment();
prizes.map((prize, index) => {
	const prizeLabel = document.createElement("div");
	prizeLabel.classList.add("prize-label");
	prizeLabel.style.transform = `rotate(${
		-anglePerPrize / 2 + anglePerPrize * (index + 1)
	}deg)`;
	prizeLabel.innerText = prize.label;
	prizeLabels.appendChild(prizeLabel);
});
turntableDom.append(prizeLabels);
// #endregion

// #region 设置转盘初始角度
const turntableBaseRotate = -anglePerPrize / 2;
turntableDom.style.transform = `rotate(${turntableBaseRotate}deg)`;
// #endregion

const getRandomNumber = (min: number, max: number, precision: number) => {
	const factor = Math.pow(10, precision);
	const random = Math.random() * (max - min) + min;
	return Math.round(random * factor) / factor;
};

lotteryBtnDom.onclick = () => {
	lotteryBtnDom.classList.add("lottery-btn--disabled");

	// #region 获取中奖结果,由后端完成
	let prizeIndex = 0;
	let resultNum = getRandomNumber(0, 1, 3);
	while (resultNum > 0) {
		resultNum -= prizes[prizeIndex].probability;
		if (resultNum > 0) {
			prizeIndex += 1;
		}
	}
	const prize = prizes[prizeIndex];
	// #endregion

	// #region 获取转盘需要旋转的角度
	const turntableRotateDegFrom = Number((anglePerPrize * prizeIndex).toFixed(1));
	const turntableRotateDegTo =
		prizeIndex === prizes.length - 1
			? 360
			: Number((anglePerPrize * (prizeIndex + 1)).toFixed(1));
	const turntableRotateDegEdgeThreshold = Number((anglePerPrize / 4).toFixed(1)); // 设定旋转到指定扇形区域的距边缘阈值(<= anglePerPrize / 2),防止出现指针指向太靠近边缘的情况
	const turntableRotateDegBase = getRandomNumber(
		turntableRotateDegFrom + turntableRotateDegEdgeThreshold,
		turntableRotateDegTo - turntableRotateDegEdgeThreshold,
		1
	);
	rotateLaps += rotateLapsBase; // 适配多次旋转的情况
	const turntableRotateDeg = -(rotateLaps * 360 + turntableRotateDegBase);
	// #endregion

	// #region 为转盘设置旋转动画
	turntableDom.style.transform = `rotate(${turntableRotateDeg}deg)`;
	turntableDom.style.transition = `transform ${animationDuration}ms cubic-bezier(.3, .9, .38, 1)`;
	// #endregion

	setTimeout(() => {
		alert(`您抽中了:${prize.label}!`);
		lotteryBtnDom.classList.remove("lottery-btn--disabled");
	}, animationDuration + 500);
};

              
            
!
999px

Console