Question

我正在开发一款使用蓝牙2.1的应用。每次应用程序变为活动状态时，它都会打开一个EASession。每次应用程序进入后台或终止时，EASession都会关闭。

如果已连接蓝牙模块，并且应用程序已启动，则会打开正常，发送/获取数据全部正常工作。

但是，如果蓝牙模块在应用程序运行时失去通信，则在重新连接并从后台打开应用程序之后。 EASession open失败。

并且没有列出连接附件。

（EAAccessory *）selectedAccessory

{

 if (_selectedAccessory == nil)

 {

      _accessoryList = [[NSMutableArray alloc] initWithArray:[[EAAccessoryManager sharedAccessoryManager] connectedAccessories]];

      NSLog(@"accessory count: %d", [_accessoryList count]);

      if ([_accessoryList count])

      {

           _selectedAccessory = [_accessoryList objectAtIndex:0];

           NSArray *protocolStrings = [_selectedAccessory protocolStrings];

           self.protocolString = [protocolStrings objectAtIndex:0];

      }else{

        UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"Alert" message:@"You don't have any machine connected.\nPlease go to Settings->Bluetooth to set up connection." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles: nil];

        [alert show];





    }

 }

 return _selectedAccessory;

}

此处[_accessoryList count]为0。

有谁知道发生了什么事？谢谢！

编辑：

我已经运行了更多测试，而这次它看起来有所不同。

- (BOOL)openSession
{
    if (_session == nil)
    {
        NSLog(@"EAController::openSession");
        [_selectedAccessory setDelegate:self];
        _session = [[EASession alloc] initWithAccessory:[self selectedAccessory] forProtocol:_protocolString];

        if (_session)
        {
            [[_session inputStream] setDelegate:self];
            [[_session inputStream] scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
            [[_session inputStream] open];

            [[_session outputStream] setDelegate:self];
            [[_session outputStream] scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
            [[_session outputStream] open];
            NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
            [defaults setBool:YES forKey:Unit_Has_Connection];
            NSLog(@"opened the session");
        }
        else
        {
            NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
            [defaults setBool:NO forKey:Unit_Has_Connection];
            NSLog(@"creating session failed");
        }
    }

    return (_session != nil);
}

这次选择的配件看起来很好。但它无法初始化会话。

在initWithAccessory行之后，它打印出ERROR：

2013-06-17 15:03:39.967 IceMachine[770:60b] ERROR - opening session failed
2013-06-17 15:03:39.968 IceMachine[770:60b] ERROR - /SourceCache/ExternalAccessory/ExternalAccessory-237/EASession.m:-[EASession dealloc] - 139 unable to close session for _accessory=0x15543fe0 and sessionID=65536

Answer 1

您必须手动将_protocolString的值添加到您应用的info.plist（支持的外部附件协议部分）。

连接的蓝牙模块未在EAAccessoryManager的connectedAccessory中显示

1 个答案: