导入框架

#import "ViewController.h"
#import <GameKit/GameKit.h>@interface ViewController () <GKPeerPickerControllerDelegate,UINavigationControllerDelegate, UIImagePickerControllerDelegate>@property (strong, nonatomic) GKSession *session;/**< 会话 */
@property (weak, nonatomic) IBOutlet UIImageView *icon;@end@implementation ViewController- (void)viewDidLoad {[super viewDidLoad];}// 从相册选择图片
- (IBAction)choose:(id)sender {if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]) {// 没有相册return;}// 创建图片选择的控制器UIImagePickerController *picker = [[UIImagePickerController alloc] init];picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;picker.delegate = self;[self presentViewController:picker animated:YES completion:nil];
}
#pragma mark - UIImagePickerControllerDelegate
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info {[picker dismissViewControllerAnimated:YES completion:nil];self.icon.image = info[UIImagePickerControllerOriginalImage];
}// 发送数据
- (IBAction)sendData:(id)sender {// 先判断要发送的数据是否存在if (!self.icon.image) {return;}// 发送数据//[self.session sendData:UIImagePNGRepresentation(self.icon.image) toPeers:<#(NSArray *)#> withDataMode:GKSendDataUnreliable error:nil];// GKSendDataUnreliable 不可靠的传输方式：1。快、2.可能会丢包、3.传递的信息不一定完整// GKSendDataReliable 可靠的传输方式：1.慢、2.不会丢包、3.直到传完为止BOOL sendSate = [self.session sendDataToAllPeers:UIImagePNGRepresentation(self.icon.image) withDataMode:GKSendDataUnreliable error:nil];}
// 建立连接
- (IBAction)build:(id)sender {GKPeerPickerController *ppc = [[GKPeerPickerController alloc] init];ppc.delegate = self;[ppc show];
}/**已经成功连接到某个设备，并且开启了连接会话@param picker 搜索框@param peerID 设备ID@param session 连接会话:通过会话可以进行数据传输*/
- (void)peerPickerController:(GKPeerPickerController *)picker didConnectPeer:(NSString *)peerID toSession:(GKSession *)session {[picker dismiss];// 标记会话self.session = session;// 设置接收数据// 设置完接收者之后，接收数据会触发 SEL = -receiveData:fromPeer:inSession:context:[self.session setDataReceiveHandler:self withContext:nil];
}/**蓝牙设备接收到数据时就会调用@param data 数据@param peer 来自哪个设备@param session 连接会话*/
- (void)receiveData:(NSData *)data fromPeer:(NSString *)peer inSession:(GKSession *)session context:(void*)context {// 显示在屏幕self.icon.image = [UIImage imageWithData:data];// 存入相册UIImageWriteToSavedPhotosAlbum(self.icon.image, nil, nil, nil);
}@end