@implementation PTPAppDelegate

    @synthesize window;

    - (void)applicationDidFinishLaunching:(UIApplication *)application
    {   
        [window makeKeyAndVisible];

         _session = [[GKSession alloc] initWithSessionID:nil  displayName:nilsessionMode:GKSessionModePeer];
         _session.delegate = self;

         GKPeerPickerController* controller = [GKPeerPickerController new];
         controller.delegate = self;
         controller.connectionTypesMask = GKPeerPickerConnectionTypeNearby;

         [controller show];
    }

    - (void)dealloc
    {
         [_session release];
         [window release];
         [super dealloc];
    }

    #pragma mark -
    #pragma mark *** GKPeerPickerControllerDelegate ***

    - (void)peerPickerController:(GKPeerPickerController *)picker didSelectConnectionType:(GKPeerPickerConnectionType)type
    {
         NSLog(@"%@", NSStringFromSelector(_cmd));
    }

    - (GKSession *)peerPickerController:(GKPeerPickerController *)picker sessionForConnectionType:(GKPeerPickerConnectionType)type
    {
         if (type == GKPeerPickerConnectionTypeNearby)
              return _session;

          returnnil;
    }

    - (void)peerPickerController:(GKPeerPickerController *)picker didConnectToPeer:(NSString *)peerID
    {
         NSLog(@"%@", NSStringFromSelector(_cmd));
    }

    - (void)peerPickerControllerDidCancel:(GKPeerPickerController *)picker
    {
         NSLog(@"%@", NSStringFromSelector(_cmd));
    }

    #pragma mark -
    #pragma mark *** GKSessionDelegate ***

    - (void)session:(GKSession *)session peer:(NSString *)peerID didChangeState:(GKPeerConnectionState)state
    {
         NSLog(@"%@", NSStringFromSelector(_cmd));
    }

    - (void)session:(GKSession *)session didReceiveConnectionRequestFromPeer:(NSString *)peerID
    {
         NSLog(@"%@", NSStringFromSelector(_cmd));
    }

    - (void)session:(GKSession *)session connectionWithPeerFailed:(NSString *)peerID withError:(NSError *)error
    {
         NSLog(@"%@", NSStringFromSelector(_cmd));
    }

    - (void)session:(GKSession *)session didFailWithError:(NSError *)error
    {
         NSLog(@"%@", NSStringFromSelector(_cmd));
    }

    @end

    - (void)applicationDidFinishLaunching:(UIApplication *)application {   


        // Override point for customization after application launch

        [window makeKeyAndVisible];

         

    picker  = [[GKPeerPickerControlleralloc] init];

         picker.delegate = self;

    picker.connectionTypesMask = GKPeerPickerConnectionTypeNearby |

    GKPeerPickerConnectionTypeOnline;

         [picker show];

    }


    - (GKSession *)peerPickerController:(GKPeerPickerController *)picker

                 sessionForConnectionType:(GKPeerPickerConnectionType)type

    {

        if (!session) {

             

            session = [[GKSession alloc] initWithSessionID:@"BluetoothTest"

       displayName :@"test"sessionMode:GKSessionModePeer];

            session.delegate = self;

        }

        return session;

    }


    - (void)session:(GKSession *)thissession peer:(NSString *)peerID

    didChangeState:(GKPeerConnectionState)state

    {

        switch (state)

        {

            case GKPeerStateConnected:

                   [thissession setDataReceiveHandler: self withContext: nil];

    // record the peerID of the other peer.

    // inform your game that a peer has connected

                   NSString *msg = @"Hi Friend";

    NSData *data = [msg dataUsingEncoding: NSASCIIStringEncoding];// create your data packet here.

                   [thissession sendDataToAllPeers: data withDataMode: GKSendDataReliable error: nil];

                   break;

            case GKPeerStateDisconnected:

    // inform your game that a peer has left.

                   break;

        }

    }




    - (void) receiveData:(NSData *)data fromPeer:(NSString *)peer inSession: (GKSession *)session context:(void *)context

    {

        // Read the bytes in data and perform an application-specific action

         NSString* aStr;

         aStr = [[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding];

         

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle :aStr  message :nildelegate:nilcancelButtonTitle:@"OK"otherButtonTitles:nil];

         [alert show];

    }

    //
    //  BluetoothSampleAppDelegate.h
    //  BluetoothSample
    //
    //  Created by Travis True on 3/18/09.
    //  Copyright University of Nevada Las Vegas 2009. All rights reserved.
    //

    #import "EAGLView.h"
    #import <GameKit/GameKit.h>

    @interface BluetoothSampleAppDelegate : NSObject <UIApplicationDelegate, GKPeerPickerControllerDelegate, GKSessionDelegate> {
        UIWindow *window;
        EAGLView *glView;
         
    GKPeerPickerController *picker;
    GKSession *session;

    int myNumber;
    NSData *myData;
    UILabel *textView;
    }

    @property (nonatomic, retain) IBOutlet UIWindow *window;
    @property (nonatomic, retain) IBOutlet EAGLView *glView;
    @property (nonatomic, retain) GKPeerPickerController *picker;
    @property (nonatomic, retain) GKSession *session;

    - (void)mySendData;

    @end

    //
    //  BluetoothSampleAppDelegate.m
    //  BluetoothSample
    //
    //  Created by Travis True on 3/18/09.
    //  Copyright University of Nevada Las Vegas 2009. All rights reserved.
    //

    #import "BluetoothSampleAppDelegate.h"

    @implementation BluetoothSampleAppDelegate
    @synthesizepicker;
    @synthesizesession;
    @synthesizewindow;
    @synthesizeglView;

    - (void)applicationDidFinishLaunching:(UIApplication *)application {
         
    // setup the text view
    myNumber = 0;
    textView = [[UILabel alloc] initWithFrame:CGRectMake(10.0f, 10.0f, 640.0f, 12.0f)];
         textView.text = [NSString stringWithFormat:@"myNumber: %i\n", myNumber];
         [window addSubview:textView];
         [window bringSubviewToFront:textView];

    // start the EAGLView
    glView.animationInterval = 1.0 / 60.0;
         [glView startAnimation];
         
    // allocate the NSData
    myData = [[NSData alloc] initWithBytes:&myNumber length:sizeof(int)];

    // allocate and setup the peer picker controller
    picker  = [[GKPeerPickerControlleralloc] init];
         picker.delegate = self;
    picker.connectionTypesMask = GKPeerPickerConnectionTypeNearby | GKPeerPickerConnectionTypeOnline;
         [picker show];
    }

    - (void)applicationWillResignActive:(UIApplication *)application {
    glView.animationInterval = 1.0 / 5.0;
    }

    - (void)applicationDidBecomeActive:(UIApplication *)application {
    glView.animationInterval = 1.0 / 60.0;
    }

    - (void)peerPickerController:(GKPeerPickerController *)picker didSelectConnectionType:(GKPeerPickerConnectionType)type {
        if(type == GKPeerPickerConnectionTypeOnline) {
            [self.picker dismiss];
            [self.picker release];
            self.picker = nil;
    // Display your own UI here.
         }
    }

    - (GKSession *) peerPickerController:(GKPeerPickerController *)picker
                        sessionForConnectionType:(GKPeerPickerConnectionType)type {
    session = [[GKSession alloc] initWithSessionID:@"FR"  displayName:nilsessionMode:GKSessionModePeer];
         session.delegate = self;
         
    return session;
    }

    - (void)session:(GKSession *)session peer:(NSString *)peerID didChangeState:(GKPeerConnectionState)state {
         switch (state) {
    case GKPeerStateConnected:
                   [self.session setDataReceiveHandler :selfwithContext:nil];
                   [self mySendData]; // start off by sending data upon connection
    break;
                   
    case GKPeerStateDisconnected:
    break;
         }
    }

    - (void)peerPickerController:(GKPeerPickerController *)picker didConnectToPeer:(NSString *)peerID {
    printf("connection was successful! start the game.\n");
    }

    - (void)peerPickerControllerDidCancel:(GKPeerPickerController *)picker {
    printf("connection attempt was canceled\n");
    }

    - (void)mySendData {
    // allocate the NSData
    myNumber++;
    myData = [[NSData alloc] initWithBytes:&myNumber length:sizeof(int)];
         [session sendDataToAllPeers :myDatawithDataMode:GKSendDataReliable error:nil];
    printf("send data: %i\n", myNumber);
         textView.text = [NSString stringWithFormat:@"myNumber: %i\n", myNumber];
    }

http://macgeeks.cn/bbs/viewtopic.php?id=7582

    - (void) receiveData:(NSData *)data fromPeer:(NSString *)peer inSession: (GKSession *)session context:(void *)context
    {
        // Read the bytes in data and perform an application-specific action, then free the NSData object
         [data getBytes:&myNumber length:sizeof(int)];
    printf("received data: %i from: %s\n", myNumber, [peer UTF8String]);
         textView.text = [NSString stringWithFormat:@"myNumber: %i\n", myNumber];
         
         [self mySendData];
    }

    - (void)dealloc
    {
         [picker release];
         [session release];
         [textView release];
         [glView release];
        [window release];
        [super dealloc];
    }

    @end