Develop Reference

Notification with setGroupSummary(true) is not visible in Android N

Tried to show 3 notification in cluster format. As per the doc, I added the setGroupSummary(true) property for the first notification.But in the result i have got only two notification. The notification which is added the GroupSummary property is not visible.
NotificationCompat.Builder firstNotification = createNotification(context,"1.Message","Here you go 1");
firstNotification .setGroupSummary(true);
firstNotification .setGroup("KEY_NOTIFICATION_GROUP");
NotificationCompat.Builder secondNotifi = createNotification(context,"2.Message","Here you go 2");
secondNotifi .setGroup("KEY_NOTIFICATION_GROUP");
NotificationCompat.Builder thirdNotifi= createNotification(context,"3.Message","Here you go 3");
thirdNotifi.setGroup("KEY_NOTIFICATION_GROUP");
Here the notification trigger,
notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
notificationManager.notify(0,firstNotification .build());
notificationManager.notify(1,secondNotifi .build());
notificationManager.notify(2,thirdNotifi.build());
And the result is,
I want to show all three notification in the cluster format without missing.
Any help will be really appreciated.

You should check the following answer :
setgroup() in notification not working
You have to create a separate group notification and set the group summary flag true only for that, and that becomes the parent notification that bundles other notifications with the same group key within itself.

setGroupSummary's purpose is to support API levels below Nougat. On Android 7.0 and higher, it shows a normal group and just uses the on click behavior (setContentIntent) and details like the summary text of the summary notification.
On Android 7.0 and lower, it shows your summary notification as a replacement for all the other notifications the group contains.

Android 7 makes a decision regarding summary notification is shown by itself. So, you want see it unless system decides that it needs to be displayed.
Solution: create a dedicated summary notification.

android system notification limit per app

This may be off topic , but I couldn't found anything for it.
Is there any limit on the number of notifications android app can display?I am facing issue after 100 notifications. There is no documentation which states this clearly.
Note: This is not really a good idea to show 100 notifications but It is required for certain reasons.

According to #Nirel's answer.
1) I tried to run the code in 3 different devices.
Surprisingly notifications beyond 50 are not showing in notification area.
It gives following error.
W/NotificationManager﹕ notify: id corrupted: sent 51, got back 0
The same error comes for subsequent calls.
I saw the source of NotificationManager , it gives this error if incoming and out id is not same. See below code.
https://github.com/android/platform_frameworks_base/blob/master/core/java/android/app/NotificationManager.java#L233
2) After I tried to notify on intervals of 100 milliseconds.
It also Gives the same error. What I tried is removed 1 notification when code is executed.
Surprisingly , notification number 153 came in status bar.
So the conclusion is that , at most 50 notifications can be there. This may be default behaviour and may can change by manufacturer as said by #Sharp Edge.
Thnx.

In API23
package com.android.server.notification;
NotificationManagerService.java
static final int MAX_PACKAGE_NOTIFICATIONS = 50;
The limit for notifications and toasts is per app 50

this post has really helped me to do research on this topic. I have written an article on this like how can you modify your logic and keep posting notifications even if you have reached the maximum limit by compromising on the oldest notifications. https://medium.com/mindorks/the-notification-limit-per-app-in-android-94af69a6862c

The notification limit dropped from 50 to 24 per appin the Android 10 notification drawer.
Read more about it here.

run this:
// prepare intent which is triggered if the
// notification is selected
Intent intent = new Intent(this, NotificationReceiver.class);
// use System.currentTimeMillis() to have a unique ID for the pending intent
PendingIntent pIntent = PendingIntent.getActivity(this, (int) System.currentTimeMillis(), intent, 0);
// build notification
// the addAction re-use the same intent to keep the example short
Notification n = new Notification.Builder(this)
.setContentTitle("New mail from " + "test#gmail.com")
.setContentText("Subject")
.setSmallIcon(R.drawable.icon)
.setContentIntent(pIntent);
NotificationManager notificationManager =
(NotificationManager) getSystemService(NOTIFICATION_SERVICE);
for(int i = 0;i<1000;i++)
{
Log.d("Tag", "notification number" + i "just published")
notificationManager.notify(i, n);
}
when the application will crash you will see how much notification you have..

notifications not getting grouped

I an a noob in android, I am trying to show notification of the push notifications I receive. Every time I receive a push notification a new notification is created in the notification bar, even if an exisiting one is present. I want them to be grouped together.
This is what I am currently doing
private void generateNotification(Context context, String ticker, String title, String msg, int icon, Intent intent)
{
int notificationId = 1;
long when = System.currentTimeMillis();
int pendingNotificationsCount = AppName.getPendingNotificationsCount() + 1;
AppName.setPendingNotificationsCount(pendingNotificationsCount);
mNotifyBuilder = new NotificationCompat.Builder(this)
.setWhen(when)
.setContentTitle(title)
.setContentText(msg)
.setAutoCancel(true)
.setContentIntent(PendingIntent.getActivity(context, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT))
.setNumber(pendingNotificationsCount);
//This prints the count correctly....
Log.d("Snehan", "Message built with Count "+pendingNotificationsCount);
Notification notif = mNotifyBuilder.build();
notif.defaults = Notification.DEFAULT_ALL;
NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
notificationManager.notify(notificationId, notif);
}
Am I doing something wrong here or missing something??

Seems Android updated the library since I last used it. But the logic is still the same. You need to save whatever the notification id was or at least give it a name you can track and check if it exists. More info can be found in the Android docs. Below is a snippet from what I mean.
To set up a notification so it can be updated, issue it with a notification ID by calling NotificationManager.notify(ID, notification). To update this notification once you've issued it, update or create a NotificationCompat.Builder object, build a Notification object from it, and issue the Notification with the same ID you used previously. If the previous notification is still visible, the system updates it from the contents of the Notification object. If the previous notification has been dismissed, a new notification is created instead.
The docs have everything you need so no need for me to write the code for you :) Hope that helped.
Edit:
Ok, so I recommend you adda a dummy icon just to see what that does. I also recommend instead of chaining all that stuff only chain the text stuff. This way you can debug a bit easier. Try to follow the doc a bit more closely. I don;t really see anything wrong with your code, but obviously something is causing the issue.
Edit 2
So it seems the icon was the problem. I've had this issue before, which is why I mentioned to add that explicitly. Hopefully when someone encounters issues with notifications please make sure you have an icon!!

Android push notification opening a custom page

my question for you is the following: I have a web app written in HTML5, wrapped as a native Android app in order to use Google Push Notifications. Because my app is using many notifications for different reasons, I want to be able to say each time a notification is received, which page to be open, like adding a 'href' in the notification intent. Is this possible?
If I wasn't clear enough please let me know.
Thanks

You can define your own notification message content. The Message builder from Google supports key value pairs to be set by the sender of the notification.
See http://developer.android.com/reference/com/google/android/gcm/server/Message.html
Example:
Message message = new Message.Builder()
.addData("link1", "http://mypage1.com")
.addData("link2", "http://mypage2.com")
.build();

When you create the notification, use setContentIntent() to attach an Intent that has been constructed to visit the right webpage:
// assuming <this> is an Activity or other Context
Intent urlIntent = new Intent(Intent.ACTION_VIEW, Uri.parse(yourUrl));
PendingIntent urlPendingIntent = PendingIntent.getActivity(this, 0 urlIntent, 0);
Notification.Builder b = new Notification.Builder(this)
.setSmallIcon(...).setContentTitle(...).setContentText(...) // etc.
.setContentIntent(urlPendingIntent);
NotificationManager noMan
= (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
noMan.notify(ID, b.build());
If you expect to have more than one of these in the notification panel at a time:
Reconsider. It's spammy to post more than one notification.
If you must, you'll need a separate ID (or separate tag) for each.

How to give counter if more than one Notifications are there

I have implemented PushNotification Using C2dm. I am getting notification from c2dm also. My problem is I want to give a counter when I get more than one notifications, I mean like "You have a Notification(count)". How can I implement this.

you can do to set the number value into the Notification object
Notification notifyDetails = new Notification(R.drawable.alarm,intent.getExtras().getString(KEY_TITLE),System.currentTimeMillis());
notifyDetails.number = 1; ////// here you can pass the counter value which will so you the number
here is the link
http://developer.android.com/reference/android/app/Notification.html#number
http://developer.android.com/guide/topics/ui/notifiers/notifications.html
Android Notification Bar Number

Are you looking for Notification#number?

NotificationManager notificationManager =(NotificationManager)context.getSystemService(NOTIFICATION_SERVICE);
notification.setNumber(1);

NotificationManager notificationManager=(NotificationManager)context.getSystemService(NOTIFICATION_SERVICE);
This creates the notificationManager class instance. Then you will have notification object with which you can do any adjustment. To set the number of the messages you have received, simply set this:
notification.setNumber(1);