前言

类似与抖音、小红书里面的评论框。默认显示在页面底部，评论、回复时弹起按键与输入框（也可默认不显示，只有评论、回复时弹起示），如下图：

小程序评论、回复框.jpg

实现代码

• test.wxml

<!--pages/test/test.wxml-->
<view class="container">
  <button bindtap="bindReply">回复</button>
  <view class="release">
    <textarea 
      class="text"
      placeholder-class="releaseInput"
      value="{{content}}"
      fixed="true" 
      maxlength="120" 
      show-confirm-bar="{{false}}" 
      cursor-spacing="15" 
      auto-height="true" 
      focus="{{focus}}"
      placeholder="回复 {{user.name}}"
      value="{{content}}"
      bindinput="contentInput"></textarea>
    <view class="submit" bindtap="comment">发送</view>
  </view>
</view>

• test.wxss

/* pages/test/test.wxss */
.release{
  font-size: 14px;
  background-color: #fff;
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  box-sizing: border-box;
  position: fixed;
  left: 0;
  bottom: 0;
  width: 100%;
  padding: 5px 0 5px 15px;
}
.releaseInput{
  color: #ccc;
}
.release .text{
  width: 302px;
  min-height: 17px;
  max-height: 51px;
  line-height: 17px;
  border-width: 7px 10px;
  border-style: solid;
  border-color: #fff;
  background-color: #fff;
}
.release .submit{
  color: #6c0;
  width: 58px;
  height: 32px;
  line-height: 32px;
  text-align: center;
}

• test.js

//test/test.js
Page({
  data: {
    content: '',
    focus: false
  },
  bindReply(e) {
    this.setData({
      focus: true
    });
  },
  contentInput(e) { //当输入框的值发生改变时，获取
    this.setData({
      content: e.detail.value
    });
  }
})