我有下面的代码。它工作，但输入很小。我希望它看起来像任何其他引导输入，即。填充整个div容器。我已经安装了引导主题。我尝试使用.Form-Control类。
<div class="row">
<div class="col-12 col-md-6">
<select class="states" name="states[]" multiple="multiple">
<option value="AL">Alabama</option>
<option value="WY">Wyoming</option>
</select>
</div>
</div>
$(function() {
$(".states").select2({
theme: "bootstrap"
});
});
只需使用css.states{width：100%；}
null
.row {
background-color:lightgray;
}
.states{
width:100%;
}<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" rel="stylesheet"/>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.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="row">
<div class="col-md-12 col-md-6">
<select class="states" name="states[]" multiple="multiple">
<option value="AL">Alabama</option>
<option value="WY">Wyoming</option>
</select>
</div>
</div>