问题
I need a custom combo box. So, I implemented with ul. The problem is I can't get combo box list opens on top by clicking the button. While showing ul, it moves button to bottom of the webpage.
Code:
ul{
width: 100px;
background-color: rgb(224, 224, 224);
border-radius: 4px;
border: 1px solid black;
padding: 0;
margin: 0;
}
ul li{
list-style: none;
cursor: pointer;
padding: 4px 10px;
}
li:hover{
background-color: white;
}
div{
width: 100%;
height: 40px;
background-color: bisque;
}
section{
height: 400px;
background-color: #525252;
}
button{
width: 100px;
height: 100%;
margin: 0;
} <!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<link rel="stylesheet" href="style.css">
</head>
<body>
<section>
<p>Some content</p>
</section>
<div>
<ul>
<li>Parrot</li>
<li>Dog</li>
<li>Cat</li>
<li>Squirrel</li>
<li>Otter</li>
<li>Cow</li>
<li>Goat</li>
<li>Finch</li>
</ul>
<button onclick="showPop()">Pet</button>
</div>
<script>
let ul = document.getElementsByTagName('ul')[0]
onload = function(){
ul.style.display = 'none'
}
function showPop(){
if(ul.style.display == 'none'){
ul.style.display = 'block'
}else{
ul.style.display = 'none'
}
}
</script>
</body>
</html>Here, I want to keep the ul inside the body.div. I just want to make it pop up like combo box with custom position. Please refer attached images.
Current Design:
I want it be like:
How can I make it with CSS? Thank you all in advance...
回答1:
Try this:
ul{
width: 100px;
background-color: rgb(224, 224, 224);
border-radius: 4px;
border: 1px solid black;
padding: 0;
margin: 0;
position: absolute;
bottom: 40px;
z-index: 9;
}
ul li{
list-style: none;
cursor: pointer;
padding: 4px 10px;
}
li:hover{
background-color: white;
}
div{
width: 100%;
height: 40px;
background-color: bisque;
position: relative;
}
section{
height: 400px;
background-color: #525252;
}
button{
width: 100px;
height: 100%;
margin: 0;
}<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<link rel="stylesheet" href="style.css">
</head>
<body>
<section>
<p>Some content</p>
</section>
<div>
<ul>
<li>Parrot</li>
<li>Dog</li>
<li>Cat</li>
<li>Squirrel</li>
<li>Otter</li>
<li>Cow</li>
<li>Goat</li>
<li>Finch</li>
</ul>
<button onclick="showPop()">Pet</button>
</div>
<script>
let ul = document.getElementsByTagName('ul')[0]
onload = function(){
ul.style.display = 'none'
}
function showPop(){
if(ul.style.display == 'none'){
ul.style.display = 'block'
}else{
ul.style.display = 'none'
}
}
</script>
</body>
</html>回答2:
Try to use position absolute for your list and set position relative for ul parent.
ul {
width: 100px;
background-color: rgb(224, 224, 224);
border-radius: 4px;
border: 1px solid black;
padding: 0;
margin: 0;
bottom: 40px;
left: 0;
position: absolute;
}
ul li {
list-style: none;
cursor: pointer;
padding: 4px 10px;
}
li:hover {
background-color: white;
}
div {
width: 100%;
height: 40px;
position: relative;
background-color: bisque;
}
section {
height: 400px;
background-color: #525252;
}
button {
width: 100px;
height: 100%;
margin: 0;
}<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<link rel="stylesheet" href="style.css">
</head>
<body>
<section>
<p>Some content</p>
</section>
<div>
<ul>
<li>Parrot</li>
<li>Dog</li>
<li>Cat</li>
<li>Squirrel</li>
<li>Otter</li>
<li>Cow</li>
<li>Goat</li>
<li>Finch</li>
</ul>
<button onclick="showPop()">Pet</button>
</div>
<script>
let ul = document.getElementsByTagName('ul')[0]
onload = function() {
ul.style.display = 'none'
}
function showPop() {
if (ul.style.display == 'none') {
ul.style.display = 'block'
} else {
ul.style.display = 'none'
}
}
</script>
</body>
</html>回答3:
I have modified your CSS little bit. Please check the snippet.
let ul = document.getElementsByTagName('ul')[0]
onload = function(){
ul.style.display = 'none'
}
function showPop(){
if(ul.style.display == 'none'){
ul.style.display = 'block'
}else{
ul.style.display = 'none'
}
}ul{
width: 100px;
background-color: rgb(224, 224, 224);
border-radius: 4px;
border: 1px solid black;
padding: 0;
margin: 0;
position: absolute;
bottom: 40px;
}
ul li{
list-style: none;
cursor: pointer;
padding: 4px 10px;
}
li:hover{
background-color: white;
}
div{
width: 100%;
height: 40px;
background-color: bisque;
}
section{
height: 400px;
background-color: #525252;
}
button{
width: 100px;
height: 100%;
margin: 0;
position: relative;
display: inline-block;
}
.dropup{
position: relative;
display: inline-block;
}<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<section>
<p>Some content</p>
</section>
<div class='dropup'>
<ul>
<li>Parrot</li>
<li>Dog</li>
<li>Cat</li>
<li>Squirrel</li>
<li>Otter</li>
<li>Cow</li>
<li>Goat</li>
<li>Finch</li>
</ul>
<button onclick="showPop()">Pet</button>
</div>来源：https://stackoverflow.com/questions/60484852/css-custom-combobox-issue