picker-view-column 赋值后 切换页面onShow后会被初始化2次

onShow: function () {
    console.log('onShow');
    var that=this;
    var date = new Date();
    var hour = date.getHours();
    var minute = date.getMinutes();

    var hourPicker = hour + 1;
    var minutePicker = parseInt(minute / 5) + 1;
    if (hourPicker > 23) {
      hourPicker = 23;
    }
    if (minutePicker > 11) {
      minutePicker = 11;
    }

    that.setData({
      TimePickerValue: [0, hourPicker, minutePicker],
    })

  },

首次打开该界面正常，第2次打开，会被赋值为[0, hourPicker, minutePicker]，然后再初始化为[0, 0, 0]， 不知道是什么问题？为什么还是被初始化成[0, 0, 0]