【问题标题】：How to increase element's width automatically when the scrollbar appears?滚动条出现时如何自动增加元素的宽度？
【发布时间】：2020-11-30 23:58:11
【问题描述】：
当用户减小浏览器的宽度时，我正在制作一个迷你侧边栏。当我使用height css 属性时，我遇到了困难。我允许用户滚动侧边栏。
但是我不知道如何在垂直滚动条出现时自动增加侧边栏的宽度。
/* START - bootstrap */
.list-unstyled {
padding-left: 0;
list-style: none;
}
.m-auto {
margin: auto;
}
.text-light {
color: rgb(248, 249, 250);
}
.text-center {
text-align: center;
}
.p-3 {
padding: 1rem!important;
}
/* END - bootstrap */
.sidebar-medium {
overflow-x: hidden;
overflow-y: auto;
display: block;
top: 0;
bottom: 0;
width: 60px;
position: fixed;
background-image: linear-gradient(to right, #ff758c 0%, #ff7eb3 100%);
}
li {
cursor: pointer;
user-select: none;
font-size: 20px;
}
li:hover {
background: rgba(255, 255, 255, 0.4);
}
.avatar {
width: 30px;
height: 30px;
background-size: 30px 30px;
clip-path: polygon(50% 0%, 90% 20%, 100% 60%, 75% 100%, 25% 100%, 0% 60%, 10% 20%);
}
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.14.0/css/all.min.css" />
<div class="shadow-sm text-light sidebar-medium">
<ul class="list-unstyled mb-0">
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto avatar" style="background-image: url('https://i.stack.imgur.com/5Jv5C.jpg?s=328&g=1');"></div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-user-tie"></i>
</div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-radiation"></i>
</div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-history"></i>
</div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-envelope"></i>
</div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-bell"></i>
</div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-bookmark"></i>
</div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-exclamation-triangle"></i>
</div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-exclamation-circle"></i>
</div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-cogs"></i>
</div>
</li>
</ul>
</div>
屏幕截图（有和没有滚动条）：
在这种情况下如何自动增加侧边栏的宽度（不使用 javascript）？
【问题讨论】：
标签：
html
css
twitter-bootstrap
media-queries
【解决方案1】：
一种可能的解决方案是查询height。
@media (max-height: 570px) { /* this is when the scrollbar appears */
.sidebar-medium {
width: 100px;
}
}
.list-unstyled {
padding-left: 0;
list-style: none;
}
.m-auto {
margin: auto;
}
.text-light {
color: rgb(248, 249, 250);
}
.text-center {
text-align: center;
}
.p-3 {
padding: 1rem !important;
}
/* END - bootstrap */
.sidebar-medium {
overflow-x: hidden;
overflow-y: auto;
display: block;
top: 0;
bottom: 0;
width: 60px;
position: fixed;
background-image: linear-gradient(to right, #ff758c 0%, #ff7eb3 100%);
transition: width 0.3s;
}
li {
cursor: pointer;
user-select: none;
font-size: 20px;
}
li:hover {
background: rgba(255, 255, 255, 0.4);
}
.avatar {
width: 30px;
height: 30px;
background-size: 30px 30px;
clip-path: polygon( 50% 0%, 90% 20%, 100% 60%, 75% 100%, 25% 100%, 0% 60%, 10% 20%);
}
@media (max-height: 570px) {
.sidebar-medium {
width: 100px;
}
}
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.14.0/css/all.min.css" />
<div class="shadow-sm text-light sidebar-medium">
<ul class="list-unstyled mb-0">
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto avatar" style="
background-image: url('https://i.stack.imgur.com/5Jv5C.jpg?s=328&g=1');
"></div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-user-tie"></i>
</div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-radiation"></i>
</div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-history"></i>
</div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-envelope"></i>
</div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-bell"></i>
</div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-bookmark"></i>
</div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-exclamation-triangle"></i>
</div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-exclamation-circle"></i>
</div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-cogs"></i>
</div>
</li>
</ul>
</div>
【解决方案2】：
您可以随时使用::-webkit-scrollbar 以获得更好的视觉效果：
/* START - bootstrap */
.list-unstyled {
padding-left: 0;
list-style: none;
}
.m-auto {
margin: auto;
}
.text-light {
color: rgb(248, 249, 250);
}
.text-center {
text-align: center;
}
.p-3 {
padding: 1rem !important;
}
/* END - bootstrap */
.sidebar-medium {
overflow-x: hidden;
overflow-y: auto;
display: block;
top: 0;
bottom: 0;
width: 60px;
position: fixed;
background-image: linear-gradient(to right, #ff758c 0%, #ff7eb3 100%);
}
li {
cursor: pointer;
user-select: none;
font-size: 20px;
}
li:hover {
background: rgba(255, 255, 255, 0.4);
}
.avatar {
width: 30px;
height: 30px;
background-size: 30px 30px;
clip-path: polygon(50% 0%, 90% 20%, 100% 60%, 75% 100%, 25% 100%, 0% 60%, 10% 20%);
}
::-webkit-scrollbar {
width: 2px;
}
::-webkit-scrollbar-thumb {
background-color: gray;
border-radius: 5px;
}
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.14.0/css/all.min.css" />
<div class="shadow-sm text-light sidebar-medium">
<ul class="list-unstyled mb-0">
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto avatar" style="background-image: url('https://i.stack.imgur.com/5Jv5C.jpg?s=328&g=1');"></div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-user-tie"></i>
</div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-radiation"></i>
</div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-history"></i>
</div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-envelope"></i>
</div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-bell"></i>
</div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-bookmark"></i>
</div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-exclamation-triangle"></i>
</div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-exclamation-circle"></i>
</div>
</li>
<li class="text-center p-3">
<div class="align-self-center d-inline-block m-auto text-center">
<i class="fas fa-cogs"></i>
</div>
</li>
</ul>
</div>
【讨论】：
-
谢谢！但是来自the docs：This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future. 我正在寻找更好的解决方案，但谢谢！