layui-form主动trigger事件select|checkbox|radio

实例：

<div class="layui-form-item">

  <div class="layui-form-label">审核</div>
  <div class="layui-inline">
    <volist name=":C('CHECKED')" id="vo">
      <input type="radio" lay-filter="jf_checked" name="jf_checked" value="{$key}" title="{$vo['label']}" {$row[ 'jf_checked']==$key? 'checked': ''}></volist>
  </div>
  <div id="reason-box" class="layui-inline" style="width:300px;">
    <input name="jf_reason" value="{$row['jf_reason']}" class="layui-input" placeholder="驳回原因" /></div>
</div>
<script>form.on('radio(jf_checked)',
  function(e) {
    if (e.value == 2) {
      $('#reason-box').show()
    } else {
      $('#reason-box').hide()
    }
  })

  $('[name=jf_checked]:checked').next().trigger('click')</script>