HTML

<div class="panel" id="<?PHP echo $id; ?>">
        <div class="panel-title"><?PHP the_title(); ?></div>
        <div id="collapse-<?PHP echo $id; ?>" class="panel-collapse collapse" style="overflow:hidden; display: block;">
            <div class="panel-body"><?PHP the_content(); ?></div>
        </div>
        <a data-toggle="collapse" data-parent="#accordion" href="#collapse-<?PHP echo $id; ?>" class="collapsed read_more" id="btn-collapse-<?PHP echo $id; ?>">Read More &raquo;</a>
    </div>

JS

$('.panel-collapse').on('shown.bs.collapse',function () {
    var collapse_id = $( this ).attr("id");
    $(".panel > #btn-"+collapse_id).text("Close");
});

$('.panel-collapse').on('hidden.bs.collapse',function () {
    var collapse_id = $( this ).attr("id");
    $(".panel > #btn-"+collapse_id).text("Read More");
});

我确实遵循了official site的所有内容.

我试过的：

这个tranisiton CSS崩溃类

.panel .collapsing{
    height: 100px !important;
    -moz-transition : height 5s;
    -webkit-transition : height 5s;
    -o-transition : height 5s;
    transition : height 5s; 
}