js点击控制全屏显示

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Fullscreen Example</title>
    <style>
        #fullscreenElement {
            width: 300px;
            height: 200px;
            background-color: lightblue;
            text-align: center;
            line-height: 200px;
        }
    </style>
</head>
<body>
    <div id="fullscreenElement">Click me to go fullscreen!</div>
    <button onclick="toggleFullscreen(document.getElementById('fullscreenElement'))">Toggle Fullscreen</button>

    <script>
        function toggleFullscreen(element) {
            if (!document.fullscreenElement) {
                element.requestFullscreen().catch(err => {
                    alert(`Error attempting to enable full-screen mode: ${err.message} (${err.name})`);
                });
            } else {
                if (document.exitFullscreen) {
                    document.exitFullscreen();
                }
            }
        }
    </script>
</body>
</html>