• pushsetup(){
const options: PushOptions = {
     android: {
       senderID: 'xxxxxxxxxx'
     },
     ios: {
       alert: 'true',
       badge: true,
       sound: 'false'
     },
     windows: {},

   };


   const pushObject: PushObject = this.push.init(options);

   pushObject.on('notification').subscribe((notification: any) => 
 {

   if (notification.additionalData.foreground) {
     let youralert = this.alertCtrl.create({
       title: 'New Push notification',
       message: notification.message
     });
     youralert.present();

   } else {

    // var navigate = notification.additionalData.nav;

   }
 });


   pushObject.on('registration').subscribe((registration: any) => 
 {
   let youralert = this.alertCtrl.create({
     title: 'New Push notification',
     message: registration.registrationId
   });
   youralert.present();

 });


   pushObject.on('error').subscribe(error => alert('Error with Push plugin' + error));
 }

cordova android version-6.3.0 push plugin version 2.1.2

pushObject.on('registration') 方法被调用,我得到设备的注册ID . 当我从firebase控制台发送通知时,我会在应用程序处于后台时在顶部栏上收到通知 . 但是当应用程序处于前台时 pushObject.on('notification') 回调未被调用 . 这里的问题是什么?