第十章 JavaScript的应用 习题

1数字时钟

HTML代码

<!DOCTYPE html>
<html>
<head>
	<style type="text/css">
		@import url(./css/1.css);
	</style>
    <meta charset="UTF-8">
    <title>数字时钟</title>

</head>
<body>
	<div class="top">
		<p>数字时钟</p>
	</div>
    <div class="clock" id="clock"><script src="js/1.js"></script>
</div>
    
</body>
</html>

css代码

body{
    align-items: center;
    height: 100px;
    background-color:#ffffff;
    color: black;
    
}

.clock {
    font-size: 100px;
    border: none;
    padding: 20px;
    border-radius: 10px;
    background-color: rgba(255, 255, 255, 0.1);
	text-align: center;
}
.top,p{
	font-size: 100px;
	text-align: center;
}

function updateClock() {
    const now = new Date();
    const hours = String(now.getHours()).padStart(2, '0');
    const minutes = String(now.getMinutes()).padStart(2, '0');
    const seconds = String(now.getSeconds()).padStart(2, '0');

    const timeString = `${hours}:${minutes}:${seconds}`;
    document.getElementById('clock').textContent = timeString;
}

// 每秒更新一次时钟
setInterval(updateClock, 1000);

// 初始化时钟
updateClock();

2

<!DOCTYPE html>
<html lang="zh">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>禁止下载</title>
    <script>
        // 禁用右键菜单并弹出警告
        function showAlert(e) {
            e.preventDefault(); // 阻止默认右键菜单
            alert("禁止下载图片！"); // 弹出警告对话框
        }

        // 添加事件监听器
        document.addEventListener('DOMContentLoaded', function() {
            const images = document.querySelectorAll('img'); // 选择所有图片
            images.forEach(img => {
                img.addEventListener('contextmenu', showAlert); // 为每个图片添加右键事件
            });
        });
    </script>
</head>
<body>
    <img src="img/p1.jpg" alt="示例图片" style="max-width: 100%; height: auto;">
</body>
</html>