Bootstrap 4:在foreach循环中，将一个图标与另一个图标交换的最佳方式是什么

Question

我想在使用折叠时将fa fa-plus替换为fa fa-minus，而在使用foreach循环时不同时切换每个图标。

这是我的代码演示。

<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" />
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css" />
<script src="https://code.jquery.com/jquery-3.4.1.slim.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.0/dist/umd/popper.min.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js"></script>
<div class="container h-100">
	<div class="row no-gutters border-0 rounded align-items-center mt-3">
		<div class="col-sm-4">demo 1</div>
		<div class="col-sm-4">demo 1</div>
		<div class="col-sm-3">demo 1</div>
		<div class="col-sm-1 ">
			<a class="fa fa-plus" data-toggle="collapse" href="#collapse1" aria-expanded="true" aria-controls="collapse1"></a>
		</div>
	</div><!--row-->
	<div class="collapse" id="collapse1">
		<div class="row no-gutters border-0 rounded align-items-center mt-3">
			<div class="col-sm-4">demo 1</div>
			<div class="col-sm-4">demo 1</div>
			<div class="col-sm-4">demo 1</div>
		</div><!--collapse-->
	</div>
	<div class="row no-gutters border-0 rounded align-items-center mt-3">
		<div class="col-sm-4">demo 2</div>
		<div class="col-sm-4">demo 2</div>
		<div class="col-sm-3">demo 2</div>
		<div class="col-sm-1 ">
			<a class="fa fa-plus" data-toggle="collapse" href="#collapse2" aria-expanded="true" aria-controls="collapse2"></a>
		</div>
	</div><!--row-->
	<div class="collapse" id="collapse2">
		<div class="row no-gutters border-0 rounded align-items-center mt-3">
			<div class="col-sm-4">demo 2</div>
			<div class="col-sm-4">demo 2</div>
			<div class="col-sm-4">demo 2</div>
		</div><!--collapse-->
	</div>
	<div class="row no-gutters border-0 rounded align-items-center mt-3">
		<div class="col-sm-4">demo 3</div>
		<div class="col-sm-4">demo 3</div>
		<div class="col-sm-3">demo 3</div>
		<div class="col-sm-1 ">
			<a class="fa fa-plus" data-toggle="collapse" href="#collapse3" aria-expanded="true" aria-controls="collapse3"></a>
		</div>
	</div><!--row-->
	<div class="collapse" id="collapse3">
		<div class="row no-gutters border-0 rounded align-items-center mt-3">
			<div class="col-sm-4">demo 3</div>
			<div class="col-sm-4">demo 3</div>
			<div class="col-sm-4">demo 3</div>
		</div><!--collapse-->
	</div>
</div><!--container-->

https://codepen.io/benwhittaker25/pen/rNVWyby

在bootstrap 4.4中实现这一点的最佳方法是什么？

Answer 1

您可以在点击按钮时使用事件引导触发器来完成：

$('.collapse').on('show.bs.collapse hide.bs.collapse', function () {
// Find the corresponding button
var $btn = $('[data-toggle="collapse"][href="#' + this.id + '"]');
// Find the corresponding row
var $row = $btn.closest('.row');

// Toggle classes
$btn.toggleClass('fa-minus fa-plus');
$row.toggleClass('rounded rounded-top');
});

<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" />
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css" />
<script src="https://code.jquery.com/jquery-3.4.1.slim.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.0/dist/umd/popper.min.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js"></script>
<div class="container h-100">
	<div class="row no-gutters border-0 rounded align-items-center mt-3">
		<div class="col-sm-4">demo 1</div>
		<div class="col-sm-4">demo 1</div>
		<div class="col-sm-3">demo 1</div>
		<div class="col-sm-1 ">
			<a class="fa fa-plus" data-toggle="collapse" href="#collapse1" aria-expanded="true" aria-controls="collapse1"></a>
		</div>
	</div><!--row-->
	<div class="collapse" id="collapse1">
		<div class="row no-gutters border-0 rounded align-items-center mt-3">
			<div class="col-sm-4">demo 1</div>
			<div class="col-sm-4">demo 1</div>
			<div class="col-sm-4">demo 1</div>
		</div><!--collapse-->
	</div>
	<div class="row no-gutters border-0 rounded align-items-center mt-3">
		<div class="col-sm-4">demo 2</div>
		<div class="col-sm-4">demo 2</div>
		<div class="col-sm-3">demo 2</div>
		<div class="col-sm-1 ">
			<a class="fa fa-plus" data-toggle="collapse" href="#collapse2" aria-expanded="true" aria-controls="collapse2"></a>
		</div>
	</div><!--row-->
	<div class="collapse" id="collapse2">
		<div class="row no-gutters border-0 rounded align-items-center mt-3">
			<div class="col-sm-4">demo 2</div>
			<div class="col-sm-4">demo 2</div>
			<div class="col-sm-4">demo 2</div>
		</div><!--collapse-->
	</div>
	<div class="row no-gutters border-0 rounded align-items-center mt-3">
		<div class="col-sm-4">demo 3</div>
		<div class="col-sm-4">demo 3</div>
		<div class="col-sm-3">demo 3</div>
		<div class="col-sm-1 ">
			<a class="fa fa-plus" data-toggle="collapse" href="#collapse3" aria-expanded="true" aria-controls="collapse3"></a>
		</div>
	</div><!--row-->
	<div class="collapse" id="collapse3">
		<div class="row no-gutters border-0 rounded align-items-center mt-3">
			<div class="col-sm-4">demo 3</div>
			<div class="col-sm-4">demo 3</div>
			<div class="col-sm-4">demo 3</div>
		</div><!--collapse-->
	</div>
</div><!--container-->

Answer 2

优雅的方法是使用blex显示的jquery方式。但是你也可以绑定一个点击函数，就像下面的javascript方式：

function toggleClass(item){
	if(item.classList.contains('fa-plus')){
			item.classList.remove('fa-plus');
			item.classList.add('fa-minus');
	}else{
		item.classList.remove('fa-minus');
			item.classList.add('fa-plus');
	}
}

<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" />
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css" />
<script src="https://code.jquery.com/jquery-3.4.1.slim.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.0/dist/umd/popper.min.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js"></script>
<div class="container h-100">
<div class="container h-100">
	<div class="row no-gutters border-0 rounded align-items-center mt-3">
		<div class="col-sm-4">demo 1</div>
		<div class="col-sm-4">demo 1</div>
		<div class="col-sm-3">demo 1</div>
		<div class="col-sm-1 ">
			<a class="fa fa-plus" data-toggle="collapse" href="#collapse1" aria-expanded="true" aria-controls="collapse1" onClick="toggleClass(this)"></a>
		</div>
	</div><!--row-->
	<div class="collapse" id="collapse1">
		<div class="row no-gutters border-0 rounded align-items-center mt-3">
			<div class="col-sm-4">demo 1</div>
			<div class="col-sm-4">demo 1</div>
			<div class="col-sm-4">demo 1</div>
		</div><!--collapse-->
	</div>
	<div class="row no-gutters border-0 rounded align-items-center mt-3">
		<div class="col-sm-4">demo 2</div>
		<div class="col-sm-4">demo 2</div>
		<div class="col-sm-3">demo 2</div>
		<div class="col-sm-1 ">
			<a class="fa fa-plus" data-toggle="collapse" href="#collapse2" aria-expanded="true" aria-controls="collapse2" onClick="toggleClass(this)"></a>
		</div>
	</div><!--row-->
	<div class="collapse" id="collapse2">
		<div class="row no-gutters border-0 rounded align-items-center mt-3">
			<div class="col-sm-4">demo 2</div>
			<div class="col-sm-4">demo 2</div>
			<div class="col-sm-4">demo 2</div>
		</div><!--collapse-->
	</div>
	<div class="row no-gutters border-0 rounded align-items-center mt-3">
		<div class="col-sm-4">demo 3</div>
		<div class="col-sm-4">demo 3</div>
		<div class="col-sm-3">demo 3</div>
		<div class="col-sm-1 ">
			<a class="fa fa-plus" data-toggle="collapse" href="#collapse3" aria-expanded="true" aria-controls="collapse3" onClick="toggleClass(this)"></a>
		</div>
	</div><!--row-->
	<div class="collapse" id="collapse3">
		<div class="row no-gutters border-0 rounded align-items-center mt-3" >
			<div class="col-sm-4">demo 3</div>
			<div class="col-sm-4">demo 3</div>
			<div class="col-sm-4">demo 3</div>
		</div><!--collapse-->
	</div>
</div><!--container-->