<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
.board {
width: 460px;
height: 300px;
/* background-color: aqua; */
}
#board {
font-size: 2em;
width: 400px;
height: 200px;
}
</style>
</head>
<body>
<div class="board">
<p>留言板</p>
<textarea name="board" id="board"></textarea>
<button>发布</button>
</div>
<div class="info">
<ul>
<span>暂无留言</span>
</ul>
</div>
<script>
let board = document.querySelector('textarea');
let btn = document.querySelector('button');
let span = document.querySelector('span');
btn.onclick = function () {
let date = new Date();
let time = `${date.getFullYear()}年${date.getMonth() + 1}月${date.getDate()}日 ${date.getHours()}时${date.getMinutes()}分${date.getSeconds()}秒`
// 先拿到留言板的内容
let c = board.value;
if (c.trim().length != 0) {
// 添加li元素
let li = document.createElement('li');
let ul = document.querySelector('ul');
ul.insertBefore(li, ul.children[0]);
ul.children[0].innerHTML = c + '<br>' + time;
span.style.display = 'none'
} else {
alert('不可空白留言哦!')
}
board.value = ''
}
</script>
</body>
</html>