my.offScreenOrientationChange

// Remove all orientation change listeners
my.offScreenOrientationChange();

Page({
  onLoad() {
    my.onScreenOrientationChange(this.handleOrientation);
  },

  handleOrientation(res) {
    console.log('New orientation:', res.orientation);
  },

  onUnload() {
    my.offScreenOrientationChange(this.handleOrientation);
  }
});

Page({
  data: {
    orientationListenerActive: false
  },

  toggleOrientationListener() {
    if (this.data.orientationListenerActive) {
      my.offScreenOrientationChange(this.onOrientationChange);
      this.setData({ orientationListenerActive: false });
    } else {
      my.onScreenOrientationChange(this.onOrientationChange);
      this.setData({ orientationListenerActive: true });
    }
  },

  onOrientationChange(res) {
    this.setData({ orientation: res.orientation });
  }
});