Comments on: Android - binding to the Music app service to find currently playing song

By: Jorge Rivera

Jorge Rivera — Thu, 10 Dec 2009 19:38:46 +0000

Hi,

Thanks a lot for the post, it was really helpful!

Has anyone tried to enqueue a list of songs using the .enqueue method? I have a little problem with it: I send a bunch of songs and only the first HALF of the songs get added to the list. I tried using the NOW, NEXT and LAST position options, and various sizes of lists of songs. For an odd number of songs, it adds half of (list+1).

Any ideas?

By: NPS

NPS — Sat, 05 Dec 2009 21:34:24 +0000

Hi can you pls give us a working example ,
What we are trying to do is tag the currently playing song so for that we need to get the info like the actual path to the song and also the artist info and all some how i cannot find the IMediaPlaybackService.aidl file in my android sdk

could you direct me towards that

By: Sathya

Sathya — Mon, 30 Nov 2009 14:46:13 +0000

Hi MarGau,

Thanks for the reply. It worked..

By: MarGau

MarGau — Fri, 20 Nov 2009 14:16:00 +0000

The problem is that the IMediaPlaybackService needs to be defined within package com.android.music you cannot change this as you then experience the security exception.
The exception basically says that the expected interface is “com.android.music.IMediaPlaybackService” whereas you defined something else.

In order to fix this you need to have in your source tree:
src\com\android\music\IMediaPlaybackService.aidl
parallel to your code. Then you don’t have to rename the package and everything works fine.

By: Sathya

Sathya — Fri, 20 Nov 2009 06:26:46 +0000

Hi,

Thanks for the article..It really helped us to start the application. But when I tried the example in emulator I am getting an exception on trying to use the interface functions…It throws the exception “Binder invocation to an incorrect interface”

The following are the steps followed
1) Copied the AIDL file (IMediaPlayBackService.aidl) to my package folder
2) Renamed the package in teh aidl file to my application(As it shown error when include to the package folder)
3) Bind a service.
4) And tried to use the service in the onServiceCOnnected callback function after getting the interface using the code
mService = IMediaPlaybackService.Stub.asInterface((IBinder)service);

But exception is thrown on trying to use the interface functions.

Could you please let me know what might be the problem?

Thanks in advance for the reply.

By: Sathya

Sathya — Fri, 20 Nov 2009 06:26:11 +0000

Hi,

Thanks for the artcile..It really helped us to start the application. But when I tried the example in emulator I am getting an exception on trying to use the interface functions…It throws the exception “Binder invocation to an incorrect interface”

But exception is thrown on trying to use the interface functions.

Could you please let me know what might be the problem?

Thanks in advance for the reply.

By: music

music — Tue, 17 Nov 2009 14:36:04 +0000

@ud

bindService is asynchronous. You can only use the service after onServiceConnected was called.

By: music

music — Tue, 17 Nov 2009 14:34:23 +0000

Thanks for this article! It describes just, what I am about to try. But I ran into a problem:
The catch clause catches a Security Exception “Binder invocation to an incorrect interface”

I copied the aidl file to my project and changed the package to my package. When I run my test app in the emulator it connects to the service, but when I try tu use it I get the mentioned exception.

Any idea what might be the problem? Am I using the wrong aidl file?

By: ud

ud — Wed, 11 Nov 2009 13:28:44 +0000

@adam..
plz tell ur silly mistake.. i m getting the same NullPtrExp. Im calling bindService(xx) before using the methods in service. but still getting the exception.
The main thing is that, when i call some methods on some button click, it works fine. But when I call the same methods in onStart() or onCreate() of Activity, I get NullptrExp.
any help???

By: dghgh

dghgh — Sun, 08 Nov 2009 04:49:41 +0000

what was the silly mistake? I keep getting the NullPointerException when i call my services method and i prettymuch followed the tutorials.