所以我是 javascript 的初学者,我正在编写一个用户名创建表单,该表单在指定的容器中显示创建的用户名。我已经制作了表格,并且
EventListener
知道我何时提交表格。提交表单时发生的函数使表单不可见并将项目设置为 localstorage
。它还在容器中显示创建的用户名。(注意:我知道我编码的内容在代码片段中不起作用,但我在实际的 html 文件中进行了测试并且它有效)。我想知道,如果用户名已经存在,如何使表单永远不可见(即使在页面重新加载时),以及如何使用户名在页面重新加载时保留在 h1 容器中。感谢所有帮助!
<!DOCTYPE html>
<html>
<body>
<form id="username-creator" class="username-creator">
<input type="text" id="username-creator-input" required>
<button type="submit">Submit</button>
</form>
<div id="username-container">
<h1 id="username-container-h1">
<!-- This is where the created username goes -->
</h1>
</div>
<script>
document.getElementById('username-creator').addEventListener('submit', function(event) {
event.preventDefault();
var username = document.getElementById('username-creator-input').value;
localStorage.setItem('username', username);
document.getElementById('username-creator').style.display = "none";
document.getElementById('username-container-h1').innerText = username;
});
</script>
</body>
</html>
您可以修改代码以检查
localstorage
中是否存在存储的用户名,并相应地调整表单的可见性。
这是更新代码:
<!DOCTYPE html>
<html>
<body>
<form id="username-creator" class="username-creator">
<input type="text" id="username-creator-input" required>
<button type="submit">Submit</button>
</form>
<div id="username-container">
<h1 id="username-container-h1">
<!-- This is where the created username goes -->
</h1>
</div>
<script>
var storedUsername = localStorage.getItem('username');
if (storedUsername) {
document.getElementById('username-creator').style.display = "none";
document.getElementById('username-container-h1').innerText = storedUsername;
}
document.getElementById('username-creator').addEventListener('submit', function(event) {
event.preventDefault();
var username = document.getElementById('username-creator-input').value;
localStorage.setItem('username', username);
document.getElementById('username-creator').style.display = "none";
document.getElementById('username-container-h1').innerText = username;
});
</script>
</body>
</html>