微信小程序的分享功能。分享给A，A点进来增加券的个数

<button class="invite_btn" hover-class="none" open-type="share">立即邀请</button>

// 用户分享
  onShareAppMessage: function (ress) {
    that = this;
    const { from, target } = ress;
    that.setData({
      isShowInvite: false
    })
    return {
      title: '', // 转发标题
      path: '/pages/bar/teach/teach-assistant?rootOpenId=' + wx.getStorageSync('openId'),
      imageUrl: '/images/cover01.png'
    }
  }

 在首页接口里面判断：

let globalOption = {};
onLoad(option) {
    globalOption = option;
}

getIndexImg() {   // 静态图片
    that = this;
    var url = '/v1/paper/getIndexData.do';
    let params = {
      session: wx.getStorageSync('session'),
    }
    if (globalOption.rootOpenId) {     // 是别人点进来的
      const { rootOpenId } = globalOption;
      params.rootOpenId = rootOpenId;
    }
     httpUtil.postData(url, params, '', function (res) {})
}