如何在使用html的下拉菜单中将鼠标悬停在下拉式菜单中时保持父菜单悬停？

要实现HTML下拉菜单中鼠标悬停时保持父菜单悬停的效果，可以通过CSS和JavaScript来完成。以下是一个简单的示例，展示了如何实现这一功能：

HTML结构

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Dropdown Menu</title>
    <link rel="stylesheet" href="styles.css">
</head>
<body>
    <nav>
        <ul class="menu">
            <li class="menu-item">
                <a href="#">Home</a>
            </li>
            <li class="menu-item dropdown">
                <a href="#" class="dropbtn">Services</a>
                <div class="dropdown-content">
                    <a href="#">Service 1</a>
                    <a href="#">Service 2</a>
                    <a href="#">Service 3</a>
                </div>
            </li>
            <li class="menu-item">
                <a href="#">About</a>
            </li>
        </ul>
    </nav>
    <script src="script.js"></script>
</body>
</html>

CSS样式

/* styles.css */
body {
    font-family: Arial, sans-serif;
}

.menu {
    list-style-type: none;
    margin: 0;
    padding: 0;
    display: flex;
    background-color: #333;
}

.menu-item {
    position: relative;
}

.menu-item a, .dropbtn {
    display: inline-block;
    color: white;
    text-align: center;
    padding: 14px 20px;
    text-decoration: none;
}

.menu-item a:hover, .dropbtn:hover {
    background-color: #575757;
}

.dropdown-content {
    display: none;
    position: absolute;
    background-color: #f9f9f9;
    min-width: 160px;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
    z-index: 1;
}

.dropdown-content a {
    color: black;
    padding: 12px 16px;
    text-decoration: none;
    display: block;
    text-align: left;
}

.dropdown-content a:hover {
    background-color: #f1f1f1;
}

JavaScript代码

// script.js
document.addEventListener('DOMContentLoaded', function() {
    const dropdowns = document.querySelectorAll('.dropdown');

    dropdowns.forEach(dropdown => {
        dropdown.addEventListener('mouseover', function() {
            this.querySelector('.dropdown-content').style.display = 'block';
        });

        dropdown.addEventListener('mouseout', function() {
            this.querySelector('.dropdown-content').style.display = 'none';
        });
    });
});