如何获取showActionSheet中的值 - 微信小程序

<view class="container">
  <button type="primary" bindtap="click">按钮</button>

  <view>{{value}} </view>
</view>

Page({

  /**
   * 页面的初始数据
   */
  data: {
    value: ""
  },
  
  click: function() {
    var ithis = this;
    var list = ['A', 'B', 'C'];
    console.log(ithis)
    wx.showActionSheet({
      itemList: list,
      success(res) {
        console.log(res.tapIndex)
        console.log(res)
        console.log(list)
        ithis.setData({
          value: list[res.tapIndex]
        })
      },
      fail(res) {
        console.log(res.errMsg)
      }
    })
  }
})