Question

我有一个已发布的应用，它使用Multipeer conncectivity定期发送少量数据。我正在使用MCNearbyServiceAdvertiser和MCNearbyServiceBrowser。我测试时一切正常。但是，我一直在接收用户的崩溃报告，但不是很多，但足以引起我的注意。

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -   [__NSPlaceholderDictionary initWithObjects:forKeys:count:]: attempt to insert nil object from objects[2]'

Last Exception Backtrace:
0   CoreFoundation                       0x30b8cf03 __exceptionPreprocess + 131
1   libobjc.A.dylib                      0x3b321ce7 objc_exception_throw + 36
2   CoreFoundation                       0x30acad3f -[__NSPlaceholderDictionary initWithObjects:forKeys:count:] + 532
3   CoreFoundation                       0x30acab03 +[NSDictionary dictionaryWithObjects:forKeys:count:] + 48
4   MultipeerConnectivity                0x32420e87 -[MCNearbyServiceBrowser syncInvitePeer:toSession:withContext:timeout:] + 452
5   MultipeerConnectivity                0x324220cf __67-[MCNearbyServiceBrowser invitePeer:toSession:withContext:timeout:]_block_invoke + 84
6   libdispatch.dylib                    0x3b80ad53 _dispatch_call_block_and_release + 8
7   libdispatch.dylib                    0x3b80fcbd _dispatch_queue_drain + 486
8   libdispatch.dylib                    0x3b80cc6f _dispatch_queue_invoke + 40
9   libdispatch.dylib                    0x3b8105f1 _dispatch_root_queue_drain + 74
10  libdispatch.dylib                    0x3b8108dd _dispatch_worker_thread2 + 54
11  libsystem_pthread.dylib              0x3b93bc17 _pthread_wqthread + 296
12  libsystem_pthread.dylib              0x3b93badc start_wqthread + 6

尽管付出了很多努力，但我还是无法重建崩溃。我已经尝试将应用程序置于后台，断开连接，打开和关闭网络等。通常，在点击“重新连接按钮”之后，有时可以很好地重新连接，但不会崩溃。有没有人有关于原因的提示或至少如何强制这种情况发生？

浏览器端看起来像这样：

-(void)setUpPP{
  self.PPid = [[MCPeerID alloc] initWithDisplayName:@"PhotoFinish"];
  self.SSid = [[MCPeerID alloc] init];

  self.PPsession = [[MCSession alloc] initWithPeer:self.PPid securityIdentity:nil encryptionPreference:MCEncryptionNone];
  self.PPsession.delegate = self;

  self.PPbrowser = [[MCNearbyServiceBrowser alloc] initWithPeer:self.PPid serviceType:@"sprinttimer" ];
  self.PPbrowser.delegate = self;
  [self.PPbrowser startBrowsingForPeers];
}

-(IBAction)startSync:(id)sender {
  [self.PPbrowser invitePeer:self.SSid toSession:self.PPsession withContext:nil timeout:10];
}

-(void)session:(MCSession *)session peer:(MCPeerID *)peerID didChangeState:(MCSessionState)state{

  NSString *displayString;
  if (state == MCSessionStateConnected && self.PPsession) {
    displayString=@"Start Sender connected";

  } else if (state == MCSessionStateNotConnected && self.PPsession) {
    displayString=@"No Start Sender in range";
    connected=NO;
  }
 [self performSelectorOnMainThread:@selector(displaySync:) withObject:displayString waitUntilDone:NO];
}

-(void)browser:(MCNearbyServiceBrowser *)browser foundPeer:(MCPeerID *)peerID withDiscoveryInfo:(NSDictionary *)info{
  self.SSid=peerID;
}

Answer 1

知道哪些操作触发了startSync:会很有帮助，但在setUpPP中您要将MCPeerID（没有displayName）的无意义实例分配给self.SSid所以，如果startSync:在self.SSid获得真正的MCPeerID之前调用了self.SSid，我就会发现崩溃。

我的建议是从MCPeerID开始为零，并确保您没有发送邀请，除非该属性有值。更进一步，我不会依赖单个属性来存储startSync:，可以在{{1}}被调用之前更改它的值。

在多重连接中邀请对等方时偶尔会崩溃

1 个答案: