my.offAppHide

Page({
  onLoad() {
    // Register listener
    my.onAppHide(this.onAppHideHandler);
  },

  onUnload() {
    // Remove specific listener
    my.offAppHide(this.onAppHideHandler);
  },

  onAppHideHandler() {
    console.log('App moved to background');
  }
});

// Remove all onAppHide listeners
my.offAppHide();