Android Code Snippet Custom notifications channel

Don't use this code. Use NB6 instead.

Starting from Android 8, notifications are grouped by channels. The notification behavior depends on the channel it belongs to.
With B4A v8+ notification channels are created automatically based on the importance level.

You can use the following code to manually create a notification channel with the same id as the notification channel that will be created internally. This allows you to override the notification behavior.

Note that once a notification channel was created then you cannot change its behavior. This means that:

1. You must call this code before you initialize the notification object.
2. If you have already created a notification in the past then you need to uninstall the app to see the changes (clean the project afterward).

Sub CreateNotificationChannel(ImportanceLevel As Int)
   Dim p As Phone
   If p.SdkVersion >= 26 Then
       Dim ctxt As JavaObject
       ctxt.InitializeContext
       Dim channelId As String = "channel_" & ImportanceLevel
       Dim channel As JavaObject
       channel.InitializeNewInstance("android.app.NotificationChannel", Array(channelId, Application.LabelName, ImportanceLevel))
       'modify the channel
       'For example: disable the badge feature
       channel.RunMethod("setShowBadge", Array(False))
      
       'set it
       Dim manager As JavaObject = ctxt.RunMethod("getSystemService", Array("notification"))
       manager.RunMethod("createNotificationChannel", Array(channel))
      
   End If
End Sub

Example:

Dim n As Notification
   CreateNotificationChannel(n.IMPORTANCE_HIGH)
   n.Initialize2(n.IMPORTANCE_HIGH)
   n.Icon = "icon"
   n.SetInfo("test", "test", Main)
   n.Notify(1)

Depends on: Phone and JavaObject libraries. Requires B4A v8+

 

[Peter Simpson]

Hello @Erel,
The above code does appear to be working on all my devices both old and new.

Anyway, thank you again for the above fully working code.

 

[Erel]

Note that this code is only needed if you want to modify the channel. The built-in notification object (B4A v8+) will work on all devices as well.

 

[AndreyPozdnyakov]

Hello Mr. Erel. I need your advice on the Custom notifications channel.
In my application, I want to have 2 kinds of simple notifications (with different text):
1. Without sound, but with vibration.
2. With sound, but no vibration.
I don't quite understand: do I just need to use the built-in Notification object or do I need to create Custom notifications channels?
And another question. I am making my application based on your example MyLocation. Can I create these notification channels in the service module or should I do this in the main module?
Thank you in advance.

 

[Erel]

Don't use this code. Use NB6 instead.