我正在尝试显示和隐藏 div。我使用 w3schools ( https://www.w3schools.com/howto/tryit.asp?filename=tryhow_js_toggle_hide_show ) 中的教程，但在这个 div 中已经显示，然后你隐藏它，而我的则隐藏然后显示。所以在示例中，我只是将 display: none; 添加到 #myDIV:
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<style>
#myDIV {
width: 100%;
padding: 50px 0;
text-align: center;
background-color: lightblue;
margin-top: 20px;
display: none;
}
</style>
</head>
<body>
<p>Click the "Try it" button to toggle between hiding and showing the DIV element:</p>
<button onclick="myFunction()">Try it</button>
<div id="myDIV">
This is my DIV element.
</div>
<p><b>Note:</b> The element will not take up any space when the display property set to "none".</p>
<script>
function myFunction() {
var x = document.getElementById("myDIV");
if (x.style.display === "none") {
x.style.display = "block";
} else {
x.style.display = "none";
}
}
</script>
</body>
</html>当我第一次点击 Try it 按钮时 div 没有显示...为什么？从那时起，如果我重新单击它，它会正常显示和消失......我该如何解决这个问题？泰
最佳答案
因为第一次没有定义x.style.display!
将您的条件修改为 if (x.style.display === "none"|| !x.style.display)
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<style>
#myDIV {
width: 100%;
padding: 50px 0;
text-align: center;
background-color: lightblue;
margin-top: 20px;
display: none;
}
</style>
</head>
<body>
<p>Click the "Try it" button to toggle between hiding and showing the DIV element:</p>
<button onclick="myFunction()">Try it</button>
<div id="myDIV">
This is my DIV element.
</div>
<p><b>Note:</b> The element will not take up any space when the display property set to "none".</p>
<script>
function myFunction() {
var x = document.getElementById("myDIV");
if (x.style.display === "none" || !x.style.display) {
x.style.display = "block";
} else {
x.style.display = "none";
}
}
</script>
</body>
</html>关于HTML - 通过不显示隐藏和取消隐藏 div，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/50158365/