我使用Bootstrap 3来构建一个响应式布局，我想根据屏幕大小调整一些字体大小。 我如何使用媒体查询来实现这种逻辑?
当前回答
下面是一个更模块化的例子，使用LESS来模拟Bootstrap，而不导入LESS文件。
@screen-xs-max: 767px;
@screen-sm-min: 768px;
@screen-sm-max: 991px;
@screen-md-min: 992px;
@screen-md-max: 1199px;
@screen-lg-min: 1200px;
//xs only
@media(max-width: @screen-xs-max) {
}
//small and up
@media(min-width: @screen-sm-min) {
}
//sm only
@media(min-width: @screen-sm-min) and (max-width: @screen-sm-max) {
}
//md and up
@media(min-width: @screen-md-min) {
}
//md only
@media(min-width: @screen-md-min) and (max-width: @screen-md-max) {
}
//lg and up
@media(min-width: @screen-lg-min) {
}
其他回答
下面是一个更模块化的例子，使用LESS来模拟Bootstrap，而不导入LESS文件。
@screen-xs-max: 767px;
@screen-sm-min: 768px;
@screen-sm-max: 991px;
@screen-md-min: 992px;
@screen-md-max: 1199px;
@screen-lg-min: 1200px;
//xs only
@media(max-width: @screen-xs-max) {
}
//small and up
@media(min-width: @screen-sm-min) {
}
//sm only
@media(min-width: @screen-sm-min) and (max-width: @screen-sm-max) {
}
//md and up
@media(min-width: @screen-md-min) {
}
//md only
@media(min-width: @screen-md-min) and (max-width: @screen-md-max) {
}
//lg and up
@media(min-width: @screen-lg-min) {
}
根据其他用户的回答，我编写了这些自定义mixin，以便于使用:
减少输入
.when-xs(@rules) { @media (max-width: @screen-xs-max) { @rules(); } }
.when-sm(@rules) { @media (min-width: @screen-sm-min) { @rules(); } }
.when-md(@rules) { @media (min-width: @screen-md-min) { @rules(); } }
.when-lg(@rules) { @media (min-width: @screen-lg-min) { @rules(); } }
示例使用
body {
.when-lg({
background-color: red;
});
}
SCSS输入
@mixin when-xs() { @media (max-width: $screen-xs-max) { @content; } }
@mixin when-sm() { @media (min-width: $screen-sm-min) { @content; } }
@mixin when-md() { @media (min-width: $screen-md-min) { @content; } }
@mixin when-lg() { @media (min-width: $screen-lg-min) { @content; } }
使用示例:
body {
@include when-md {
background-color: red;
}
}
输出
@media (min-width:1200px) {
body {
background-color: red;
}
}
这里有一个更简单的一站式解决方案，包括基于媒体查询的独立响应文件。
这允许所有媒体查询逻辑和包含逻辑只存在于一个页面，即加载器。它还允许媒体查询不会使响应式样式表本身混乱。
//loader.less
// this twbs include adds all bs functionality, including added libraries such as elements.less, and our custom variables
@import '/app/Resources/less/bootstrap.less';
/*
* Our base custom twbs overrides
* (phones, xs, i.e. less than 768px, and up)
* no media query needed for this one since this is the default in Bootstrap
* All styles initially go here. When you need a larger screen override, move those
* overrides to one of the responsive files below
*/
@import 'base.less';
/*
* Our responsive overrides based on our breakpoint vars
*/
@import url("sm-min.less") (min-width: @screen-sm-min); //(tablets, 768px and up)
@import url("md-min.less") (min-width: @screen-md-min); //(desktops, 992px and up)
@import url("large-min.less") (min-width: @screen-lg-min); //(large desktops, 1200px and up)
基地。更少的会像这样
/**
* base.less
* bootstrap overrides
* Extra small devices, phones, less than 768px, and up
* No media query since this is the default in Bootstrap
* all master site styles go here
* place any responsive overrides in the perspective responsive sheets themselves
*/
body{
background-color: @fadedblue;
}
sm-min。更少的会像这样
/**
* sm-min.less
* min-width: @screen-sm-min
* Small devices (tablets, 768px and up)
*/
body{
background-color: @fadedgreen;
}
你的索引只需要加载loader。less
<link rel="stylesheet/less" type="text/css" href="loader.less" />
很简单…
这些是Bootstrap3的值:
/* Extra Small */
@media(max-width:767px){}
/* Small */
@media(min-width:768px) and (max-width:991px){}
/* Medium */
@media(min-width:992px) and (max-width:1199px){}
/* Large */
@media(min-width:1200px){}
引导3
对于Bootstrap 3 (v3.4.1)的最终版本发行版，使用了以下媒体查询，这些查询与概述可用响应类的文档相对应。 https://getbootstrap.com/docs/3.4/css/#responsive-utilities
/* Extra Small Devices, .visible-xs-* */
@media (max-width: 767px) {}
/* Small Devices, .visible-sm-* */
@media (min-width: 768px) and (max-width: 991px) {}
/* Medium Devices, .visible-md-* */
@media (min-width: 992px) and (max-width: 1199px) {}
/* Large Devices, .visible-lg-* */
@media (min-width: 1200px) {}
从Bootstrap GitHub存储库中提取的媒体查询从以下较少的文件
https://github.com/twbs/bootstrap/blob/v3.4.1/less/variables.less#L283 https://github.com/twbs/bootstrap/blob/v3.4.1/less/responsive-utilities.less
引导5
从版本5的文档中可以看到，自版本3以来，媒体查询断点已经更新，以更好地适应现代设备尺寸。
// X-Small devices (portrait phones, less than 576px)
// No media query for `xs` since this is the default in Bootstrap
// Small devices (landscape phones, 576px and up)
@media (min-width: 576px) { ... }
// Medium devices (tablets, 768px and up)
@media (min-width: 768px) { ... }
// Large devices (desktops, 992px and up)
@media (min-width: 992px) { ... }
// X-Large devices (large desktops, 1200px and up)
@media (min-width: 1200px) { ... }
// XX-Large devices (larger desktops, 1400px and up)
@media (min-width: 1400px) { ... }
来源:Bootstrap 5文档
你可以在引导GitHub存储库中看到v5.1.3的断点:-
https://github.com/twbs/bootstrap/blob/v5.1.3/scss/_variables.scss#L461 https://github.com/twbs/bootstrap/blob/v5.1.3/scss/mixins/_breakpoints.scss
更新日期:2021-12-19
