如果我包含<div class="input-group">
控件看起来更短,如果我删除这个div,那么它们是exapnding。我只是试图通过向表单添加input-group和form-group类来了解发生了什么。有人可以解释吗?自举窗体控件 - 自定义宽度
<div class="row">
<div class="col-xs-6">
<div class="panel panel-primary">
<div class="panel-heading"><h3 class="panel-title">Application Information</h3></div>
<div class="panel-body">
<div class="row">
<div class="col-lg-6 col-lg-6">
<div class ="form-group">
<label for="text" >Contract State</label>
<div class="input-group">
<select name="State" id="State" class="validate[required] form-control">
<option value="">Choose a State</option>
<option value="IL">Illinois</option>
<option value="MN">Minnesota</option>
<option value="WI">Wisconsin</option>
</select>
</div>
</div>
<div class ="form-group">
<label for="text" >Application Number</label>
<div class="input-group">
<input class="validate[required] text-input form-control" type="text" name="AppNumber" id="AppNumber" />
</div>
</div>
</div> <!-- col-lg-6 col close -->
</div> <!-- row close -->
</div> <!-- End of panel Body -->
</div><!-- End of panel -->
</div> <!-- end col-xs-6 -->
<div id ="panel2" class="col-xs-6">
<div class="panel panel-primary">
<div class="panel-heading"><h3 class="panel-title">Initial Premium</h3></div>
<div class="panel-body">
</div>
</div>
</div>
</div><!-- End of second row -->