globalData: {
    userInfo: null,
    isIphoneX: false//判断是否是iPhoneX
  },
  onShow: function() {
    var that = this;
    wx.getSystemInfo({
      success: function(res) {
        // console.log('手机信息res'+res.model)  
        let modelmes = res.model;
        if (modelmes.search('iPhone X') != -1) {
          that.globalData.isIphoneX = true
        }
      },
    })
  }

var app= getApp();
Page({
data: {
  isIphoneX: false
},
onLoad: function(){
      // 判断是否为iPhoneX
    var isIphoneX = app.globalData.isIphoneX;
    console.log(isIphoneX ? '是iPhoneX' : '不是iPhoneX')
    this.setData({
      isIphoneX: isIphoneX
    })
  }
})

  <view class="{{isIphoneX ? 'width30' : 'width10'}}"></view>