代码示例：

<view data-weui-theme="{{theme}}">
  <button class="avatar-wrapper" open-type="chooseAvatar" bindchooseavatar="onChooseAvatar">
    <image class="avatar" src="{{avatarUrl}}"></image>
  </button> 
  <form catchsubmit="formSubmit">
    <view class="row">
      <view class="text1">昵称：</view>
        <input type="nickname" class="weui-input" name="nickname" placeholder="请输入昵称"/>
    </view>
    <button type="primary" style="margin-top: 40rpx;margin-bottom: 20rpx;" form-type="submit">提交</button>
  </form>
</view>
.avatar-wrapper {
  padding: 0;
  width: 56px !important;
  border-radius: 8px;
  margin-top: 40px;
  margin-bottom: 40px;
  background-color: #fff;
}
 
.avatar {
  display: block;
  width: 56px;
  height: 56px;
}
 
.container {
  display: flex;
}
.row{
   border-top: 1px solid #ccc;
   border-bottom: 1px solid #ccc;
   display: flex;
   align-items: center;
   height: 80rpx;
   padding-left: 20rpx;
}
.text1{
    flex: 2;
}
.weui-input{
    flex: 6;
}

const app = getApp()
const defaultAvatarUrl = 'https://mmbiz.qpic.cn/mmbiz/icTdbqWNOwNRna42FI242Lcia07jQodd2FJGIYQfG0LAJGFxM4FbnQP6yfMxBgJ0F3YRqJCJ1aPAK2dQagdusBZg/0'
 
 
Page({
/**
   * 页面的初始数据
   */
  data: {
    avatarUrl: defaultAvatarUrl,
    theme: wx.getSystemInfoSync().theme,
 
  },
 
  onChooseAvatar(e) {
    const { avatarUrl } = e.detail 
   
    this.setData({
      avatarUrl,
    })
    app.globalData.userInfo.avatarUrl = avatarUrl
   
  },
  formSubmit(e){
     app.globalData.userInfo.nickName = e.detail.value.nickname
      wx.switchTab({
        url: '/pages/home/index',
      })
  },
 
 
  /**
   * 生命周期函数--监听页面加载
   */
  onLoad(options) {
    wx.onThemeChange((result) => {
      this.setData({
        theme: result.theme
      })
    })
 },

企业微信截图_17168864449899.png

button中的边框加了none还是不行

1）先给button加一个plain属性

<button class="avatar-wrapper" open-type="chooseAvatar" bindchooseavatar="onChooseAvatar"  plain>
    <image class="avatar" src="{{avatarUrl}}"></image>
  </button> 

然后找到按钮的样式加上这行代码足矣：

    button[plain]{ border:0 }

2）第二种方法就是找到按钮对根本样式做一个修改：

button::after{
 border: none;
}