html - Bootstrap Accordion - 开始全部关闭

Question

所以我的页面上有一个 bootstrap 风格的 Accordion - 但在开始时，第一个面板是打开的。我怎样才能让它在您加载页面时全部关闭？

任何帮助将不胜感激!非常感谢!

<div class="panel-group" id="accordion">
    <div class="panel panel-default">
        <div class="panel-heading">
            <h4 class="panel-title">
                <a class="accordion-toggle text-normalize" data-toggle="collapse" data-parent="#accordion" href="#panel1"><i class="fa fa-minus text-primary"></i> Overview</a>
            </h4>
        </div>
        <div id="panel1" class="panel-collapse collapse in">
            <div class="panel-body">Contents panel 1</div>
        </div>
    </div>
    <div class="panel panel-default">
        <div class="panel-heading">
            <h4 class="panel-title">
                <a class="accordion-toggle text-normalize" data-toggle="collapse" data-parent="#accordion" href="#panel2"><i class="fa fa-plus text-primary"></i> Utilities</a>
            </h4>
        </div>
        <div id="panel2" class="panel-collapse collapse">
            <div class="panel-body">Contents panel 2</div>
        </div>
    </div>
    <div class="panel panel-default">
        <div class="panel-heading">
            <h4 class="panel-title">
                <a class="accordion-toggle text-normalize" data-toggle="collapse" data-parent="#accordion" href="#panel3"><i class="fa fa-plus text-primary"></i> Organization</a>
            </h4>
        </div>
        <div id="panel3" class="panel-collapse collapse">
            <div class="panel-body">Contents panel 3</div>
        </div>
    </div>
    <div class="panel panel-default">
        <div class="panel-heading">
            <h4 class="panel-title">
                <a class="accordion-toggle text-normalize" data-toggle="collapse" data-parent="#accordion" href="#panel4"><i class="fa fa-plus text-primary"></i> Integrations</a>
            </h4>
        </div>
        <div id="panel4" class="panel-collapse collapse">
            <div class="panel-body">Contents panel 3</div>
        </div>
    </div>
    <div class="panel panel-default">
        <div class="panel-heading">
            <h4 class="panel-title">
                <a class="accordion-toggle text-normalize" data-toggle="collapse" data-parent="#accordion" href="#panel5"><i class="fa fa-plus text-primary"></i> Essentials</a>
            </h4>
        </div>
        <div id="panel5" class="panel-collapse collapse">
            <div class="panel-body">Contents panel 3</div>
        </div>
    </div>
    <div class="panel panel-default">
        <div class="panel-heading">
            <h4 class="panel-title">
                <a class="accordion-toggle text-normalize" data-toggle="collapse" data-parent="#accordion" href="#panel6"><i class="fa fa-plus text-primary"></i> Sales</a>
            </h4>
        </div>
        <div id="panel6" class="panel-collapse collapse">
            <div class="panel-body">Contents panel 3</div>
        </div>
    </div>
    <div class="panel panel-default">
        <div class="panel-heading">
            <h4 class="panel-title">
                <a class="accordion-toggle text-normalize" data-toggle="collapse" data-parent="#accordion" href="#panel7"><i class="fa fa-plus text-primary"></i> Support</a>
            </h4>
        </div>
        <div id="panel7" class="panel-collapse collapse">
            <div class="panel-body">Contents panel 3</div>
        </div>
    </div>
    <div class="panel panel-default">
        <div class="panel-heading">
            <h4 class="panel-title">
                <a class="accordion-toggle text-normalize" data-toggle="collapse" data-parent="#accordion" href="#panel8"><i class="fa fa-plus text-primary"></i> Projects</a>
            </h4>
        </div>
        <div id="panel8" class="panel-collapse collapse">
            <div class="panel-body">Contents panel 3</div>
        </div>
    </div>
</div>

Answer 1

助推器 3

只需从 panel1 中删除 .in。

<div id="panel1" class="panel-collapse collapse">
   <div class="panel-body">Contents panel 1</div>
</div>

Bootstrap 4

参见 @Syed Sajid的回答