使用GameKit实现IOS设备之间的蓝牙通信

　　该工程是使用苹果官方的GameKit框架来实现蓝牙设别之间的通信，首先当然是要在项目中加入GameKit.framework框架。工程的截图如下：

ViewController.h如下：

//
//  ViewController.h
//  GameKitDemo
//
//  Created by Fox on 12-3-14.
//  Copyright (c) 2012年 __MyCompanyName__. All rights reserved.
//

#import <UIKit/UIKit.h>
#import <GameKit/GKSession.h>
#import <GameKit/GKPeerPickerController.h>

@interface ViewController : UIViewController<GKSessionDelegate,GKPeerPickerControllerDelegate>{
    
    GKSession *currentSession;//GKSession对象用于表现两个蓝牙设备之间连接的一个会话，你也可以使用它在两个设备之间发送和接收数据。
     
    IBOutlet UITextField *txtMessage;    
    IBOutlet UIButton *connect;
    IBOutlet UIButton *disconnect;

}

@property (nonatomic, retain) GKSession *currentSession;
@property (nonatomic, retain) UITextField *txtMessage;
@property (nonatomic, retain) UIButton *connect;
@property (nonatomic, retain) UIButton *disconnect;

-(IBAction) btnSend:(id) sender;
-(IBAction) btnConnect:(id) sender;
-(IBAction) btnDisconnect:(id) sender;
-(void)mySendDataToPeers:(NSData *)data;

@end

ViewController.m如下：

//
//  ViewController.m
//  GameKitDemo
//
//  Created by Fox on 12-3-14.
//  Copyright (c) 2012年 __MyCompanyName__. All rights reserved.
//

#import "ViewController.h"
#import <GameKit/GKPeerPickerController.h>

@implementation ViewController
@synthesize currentSession;
@synthesize connect;
@synthesize disconnect;
@synthesize txtMessage;

GKPeerPickerController *picker;//GKPeerPickerController类提供了一个标准的UI使的应用程序发现并连接到其它蓝牙设备

- (void)viewDidLoad
{
    [connect setHidden:NO];
    [disconnect setHidden:YES];
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

- (void)dealloc {
    [txtMessage release];
    [currentSession release];
    
    [super dealloc];
    
}

/*
 *建立回话后，开始发送信息
 */
-(IBAction) btnSend:(id) sender{
    NSData* data;
    NSString *str = [NSString stringWithString:txtMessage.text];
    data = [str dataUsingEncoding: NSASCIIStringEncoding];
    [self mySendDataToPeers:data];
}

/*
 *利用GKPeerPickerController框架搜索附近的蓝牙设备
 */
-(IBAction) btnConnect:(id) sender{

    picker= [[GKPeerPickerController alloc] init];
    picker.delegate = self;
    picker.connectionTypesMask = GKPeerPickerConnectionTypeNearby;
    //connectionTypesMask用户可以选择的连接类型，包括两种类型：GKPeerPickerConnectionTypeNearby和GKPeerPickerConnectionTypeOnline。对于蓝牙通信，使用GKPeerPickerConnectionTypeNearby常量，GKPeerPickerConnectionTypeOnline常量表示基于互联网的连接。
    [connect setHidden:YES];
    [disconnect setHidden:NO];
    [picker show];

}


/*
 *从一个Apple设备中断开连接
 */
-(IBAction) btnDisconnect:(id) sender{
    [self.currentSession disconnectFromAllPeers];
    [self.currentSession release];
    currentSession = nil;
    [connect setHidden:NO];
    [disconnect setHidden:YES];

}


/*
 *检测到远程蓝牙设备，用户选择并连接到其中一个蓝牙设备时调用该函数
 */
- (void)peerPickerController:(GKPeerPickerController *)picker didConnectPeer:(NSString *)peerID toSession:(GKSession *) session {
     
    self.currentSession = session;//将蓝牙连接的回话session保存为当前的session
    session.delegate = self;
    [session setDataReceiveHandler:self withContext:nil];
    picker.delegate = nil;
    [picker dismiss];
    [picker autorelease];
}


/*
 *点击取消时调用该函数
 */ 
- (void)peerPickerControllerDidCancel:(GKPeerPickerController *)picker{
    
    picker.delegate = nil;
    [picker autorelease];
    [connect setHidden:NO];
    [disconnect setHidden:YES];
}

/*
 *设备连接或断开连接时调用该方法
 */
- (void)session:(GKSession *)session peer:(NSString *)peerID didChangeState:(GKPeerConnectionState)state {
    switch (state){
        case GKPeerStateConnected:
             NSLog(@"connected");
             break;
    
        case GKPeerStateDisconnected:
             NSLog(@"disconnected");
            [self.currentSession release];
            currentSession = nil;
            [connect setHidden:NO];
            [disconnect setHidden:YES];
            break;
        default:
            break;
        }
}

/*
 *向连同的一端发送数据
 */
-(void)mySendDataToPeers:(NSData *) data{
    if (currentSession)
    [self.currentSession sendDataToAllPeers:data withDataMode:GKSendDataReliable error:nil];
}


/*
 *接受发送过来的数据
 */
-(void)receiveData:(NSData *)data fromPeer:(NSString *)peer inSession:(GKSession *)session context:(void *)context {
  
    NSString* str;
    str = [[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding];
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Data received"
                                                    message:str
                                                   delegate:self
                                          cancelButtonTitle:@"OK"
                                          otherButtonTitles:nil];
    [alert show];
    [alert release];
}
 



@end

界面如下：

点击连接后，设备开始搜索附近的IOS蓝牙设备：

双方设备搜索并连接成功后，就可以通过输入框来发送消息了。

GameKit主要用于点对点的通信，常用于游戏中。所以向使用这中方法来实现IOS设备的蓝牙同其他非IOS蓝牙设备之间

的通信是比较困难的。
参考来源：http://www.cnblogs.com/KidReborn/archive/2011/10/17/2215641.html