使用css方式
html代碼
<h2>響應式判斷</h2>
<p class="example">操作瀏覽器窗口，查看效果。</p>
css樣式代碼
.example {
padding: 20px;
color: white;
}
/* Extra small devices (phones, 600px and down) */
@media only screen and (max-width: 600px) {
.example {background: red;}
}
/* Small devices (portrait tablets and large phones, 600px and up) */
@media only screen and (min-width: 600px) {
.example {background: green;}
}
/* Medium devices (landscape tablets, 768px and up) */
@media only screen and (min-width: 768px) {
.example {background: blue;}
}
/* Large devices (laptops/desktops, 992px and up) */
@media only screen and (min-width: 992px) {
.example {background: orange;}
}
/* Extra large devices (large laptops and desktops, 1200px and up) */
@media only screen and (min-width: 1200px) {
.example {background: pink;}
}
實現屏幕（窗口）不同大小，<p>標籤顯示不同的背景色；
css語法:(css有很多媒體類型)
@media mediatype and|not|only (media feature) {
CSS-Code;
}
使用javascript方式
html代碼
<body class='sidebar-collapse'></body>
js代碼
<script>
//dom加載完後執行:$(function() {}) 是$(document).ready(function()的簡寫
$(function () {
changeClass();
});
//瀏覽器的窗口大小發生改變時執行
$(window).resize(function () {
//執行代碼塊
changeClass();
});
//當屏幕小於1400時添加一個屬性，大於的時候刪除屬性
function changeClass() {
let ww = $(window).width();
if( ww > 1400 ){
$('body').removeClass('sidebar-collapse');
} else if( ww > 600 && ww < 1400 ){
$('body').addClass('sidebar-collapse');
}
}
</script>