bw_smallApp/pages/feedback/feedback.wxml

<view class="section">
  <form bindsubmit="bindFormSubmit">
    <textarea placeholder="请您留下最宝贵的意见，以便更好的为您服务" name="textarea"  bindinput="bindTextAreaBlur" value='{{userInput}}'/>
     <text class='text_number'>还可输入<text>{{int_number}}</text>字</text>
    <button form-type="submit"> 提交 </button>
  </form>
</view>