iPhone Development: Game Kit, and What is a Picker?

So as usual, I wish someone had written this in a blog post. And now that I’ve figured it out, I’m paying it forward, so to speak.

The big revelation here is: if you’re using Game Kit (GK) foundation from Apple, iPhone development 3.x SDK, then you may encounter a networking object called “PeerPickerController”. It seems pretty obvious, but it really went over my head for a while. What is it? It’s an alert window that shows you the names of other BlueTooth, or WiFi devices in your vicinity.


Here is a snapshot of one:

Some other tidbits:

When you are setting up a session, and a connection, the real final state of the connection is in a method called “did ChangeState”. The state that returns is a valid connection when it is: “GKPeerStateConnected”.

For some reason, working with this framework, there’s a lot of terms that seem obvious now, but were really confusing when we were cracking it:

– peer is any device, ANY DEVICE (including server)
– connection means literally an unsigned, ping out into the darkness
– session is on the client, and the server.

Also, (now I’m on a roll) some of this was new to me. The callbacks to this framework sometimes have nothing in them (and don’t log out STDOUT to your console):

(void)connectToPeer:(NSString *)peerID withTimeout:(NSTimeInterval)timeout{

I’m still muddling through this, but if I find out more I’ll post. Most relevant bits were from my teammate Stacie!


  1. Comment by moonlight42

    Posted on April 23, 2010 at 9:27 am

    We are involved in mobile development, specialising in the iPhone, iPad, android and blackberry. Please look at our link: http://bit.ly/dbQ9BR

  2. Comment by Henry Duke

    Posted on June 12, 2012 at 9:51 am

    As getting started with iPhone development, it was great to know about some terms related to it such as peer and connection and session was something which I was knowing before. 

  3. Comment by Micheal Marke

    Posted on May 27, 2013 at 1:31 pm

    The Android Development
    range from social media apps to news and weather apps that includes,
    like educational games to music, movies to all sorts of entertainments
    that it can imagine.

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