my.offAppShow

Page({
  onLoad() {
    // Register listener
    my.onAppShow(this.onAppShowHandler);
  },

  onUnload() {
    // Remove specific listener
    my.offAppShow(this.onAppShowHandler);
  },

  onAppShowHandler() {
    console.log('App moved to foreground');
  }
});

// Remove all onAppShow listeners
my.offAppShow();

<button size="default" onTap="removeListener" type="primary">
  Stop listening for foreground events
</button>

Page({
  onLoad() {
    my.onAppShow(this.onAppShowHandler);
  },

  onAppShowHandler() {
    console.log('App is now in foreground');
  },

  removeListener() {
    my.offAppShow(this.onAppShowHandler);
    my.showToast({ content: 'Listener removed' });
  }
});