AdminLTE主题左侧Menu菜单切换时样式自动变化代码，将下面代码添加到对应版本的AdminLTE主题的页面footer处即可。
AdminLTE 3：
<script>
$(document).ready(function() {
/** add active class and stay opened when selected */
var url = window.location;
// for sidebar menu entirely but not cover treeview
$('ul.nav-sidebar a').filter(function() {
return this.href == url;
}).addClass('active');
// for treeview
$('ul.nav-treeview a').filter(function() {
return this.href == url;
}).parentsUntil(".nav-sidebar > .nav-treeview").addClass('menu-open').prev('a').addClass('active');
})
</script>AdminLTE 2.4.*：
<script>
$(document).ready(function() {
/** add active class and stay opened when selected */
var url = window.location;
// for sidebar menu entirely but not cover treeview
$('ul.sidebar-menu a').filter(function() {
return this.href == url;
}).parent().siblings().removeClass('active').end().addClass('active');
// for treeview
$('ul.treeview-menu a').filter(function() {
return this.href == url;
}).parentsUntil(".sidebar-menu > .treeview-menu").siblings().removeClass('active').end().addClass('active');
})
</script>
