我花了两天谷歌搜索和阅读蓝牙编程指南,同时尝试拼凑一个小型Mac应用程序,它将从一个drop文件夹中检索图像,并通过蓝牙将任何新文件发送到预定的设备.似乎没有很多好的例子可供使用.
我正处于能够产生蓝牙服务浏览器并选择设备及其OBEX服务,建立服务和创建连接的地步,但之后不再发生任何事情.谁能指点我/向我展示一个可行的简单例子?
附带AppDelegate源代码.谢谢阅读!
#import "AppDelegate.h" @implementation AppDelegate - (void)applicationDidFinishLaunching:(NSNotification *)aNotification { IOBluetoothServiceBrowserController *browser = [IOBluetoothServiceBrowserController serviceBrowserController:0]; [browser runModal]; //IOBluetoothSDPServiceRecord IOBluetoothSDPServiceRecord *result = [[browser getResults] objectAtIndex:0]; [self describe:result]; if ([[result.device.name substringToIndex:8] isEqualToString:@"Polaroid"]) { printer = result.device; serviceRecord = result; [self testPrint]; } else { NSLog(@"%@ is not a valid device",result.device.name); } } - (void) testPrint { currentFilePath = @"/Users/oyvind/Desktop/_DSC8797.jpg"; [self sendFile:currentFilePath]; } - (void) sendFile:(NSString *)filePath { IOBluetoothOBEXSession *obexSession = [[IOBluetoothOBEXSession alloc] initWithSDPServiceRecord:serviceRecord]; if( obexSession != nil ) { NSLog(@"OBEX Session Established"); OBEXFileTransferServices *fst = [OBEXFileTransferServices withOBEXSession:obexSession]; OBEXDelegate *obxd = [[OBEXDelegate alloc] init]; [obxd setFile:filePath]; [fst setDelegate:obxd]; OBEXError cnctResult = [fst connectToObjectPushService]; if( cnctResult != kIOReturnSuccess ) { NSLog(@"Error creating connection"); return; } else { NSLog(@"OBEX Session Created. Sending file: %@",filePath); [fst sendFile:filePath]; [printer openConnection]; } } else { NSLog(@"Error creating OBEX session"); NSLog(@"Error sending file"); } } @end
解决方法
好;这里最终成为功能的核心部分.我制作的应用程序是Polaroid即时打印机的一种打印服务器,它只接受Object Push上的图像.
首先,确保监视文件夹存在.
/* Looks for a directory named PolaroidWatchFolder in the user's desktop directory and creates it if it does not exist. */ - (void) ensureWatchedFolderExists { NSFileManager *fileManager = [NSFileManager defaultManager]; NSURL *url = [NSURL URLWithString:@"PolaroidWatchFolder" relativeToURL:[[fileManager URLsForDirectory:NSDesktopDirectory inDomains:NSUserDomainMask] objectAtIndex:0]]; BOOL isDir; if ([fileManager fileExistsAtPath:[url path] isDirectory:&isDir] && isDir) { [self log:[NSString stringWithFormat:@"Watched folder exists at %@",[url absoluteURL]]]; watchFolderPath = url; } else { NSError *theError = nil; if (![fileManager createDirectoryAtURL:url withIntermediateDirectories:NO attributes:nil error:&theError]) { [self log:[NSString stringWithFormat:@"Watched folder could not be created at %@",[url absoluteURL]]]; } else { watchFolderPath = url; [self log:[NSString stringWithFormat:@"Watched folder created at %@",[url absoluteURL]]]; } } }
然后扫描可用的打印机:
/* Loops through all paired Bluetooth devices and retrieves OBEX Object Push service records for each device who's name starts with "Polaroid". */ - (void) findPairedDevices { NSArray *pairedDevices = [IOBluetoothDevice pairedDevices]; devicesTested = [NSMutableArray arrayWithCapacity:0]; for (IOBluetoothDevice *device in pairedDevices) { if ([self deviceQualifiesForAddOrRenew:device.name]) { BluetoothPushDevice *pushDevice = [[BluetoothPushDevice new] initWithDevice:device]; if (pushDevice != nil) { [availableDevices addObject:pushDevice]; [pushDevice testConnection]; } } } }
最后一个函数调用是BluetoothPushDevice的内置方法来测试连接.这是响应的委托处理程序:
- (void) deviceStatusHandler: (NSNotification *)notification { BluetoothPushDevice *device = [notification object]; NSString *status = [[notification userInfo] objectForKey:@"message"]; if ([devicesTested count] < [availableDevices count] && ![devicesTested containsObject:device.name]) { [devicesTested addObject:device.name]; } }
在服务器启动时,此方法将响应计时器滴答或手动扫描运行:
- (void) checkWatchedFolder { NSError *error = nil; NSArray *properties = [NSArray arrayWithObjects: NSURLLocalizedNameKey,NSURLCreationDateKey,NSURLLocalizedTypeDescriptionKey,nil]; NSArray *files = [[NSFileManager defaultManager] contentsOfDirectoryAtURL:watchFolderPath includingPropertiesForKeys:properties options:(NSDirectoryEnumerationSkipsHiddenFiles) error:&error]; if (files == nil) { [self log:@"Error reading watched folder"]; return; } if ([files count] > 0) { int newFileCount = 0; for (NSURL *url in files) { if (![filesInTransit containsObject:[url path]]) { NSLog(@"New file: %@",[url lastPathComponent]); [self sendFile:[url path]]; newFileCount++; } } } }
找到新文件后,首先需要找到一个不忙于收到打印文件的设备:
/* Loops through all discovered device service records and returns the a new OBEX session for the first it finds that is not connected (meaning it is not currently in use,connections are ad-hoc per print). */ - (BluetoothPushDevice*) getIdleDevice { for (BluetoothPushDevice *device in availableDevices) { if ([device.status isEqualToString:kBluetoothDeviceStatusReady]) { return device; } } return nil; }
然后使用此方法发送文件:
- (void) sendFile:(NSString *)filePath { BluetoothPushDevice *device = [self getIdleDevice]; if( device != nil ) { NSLog(@"%@ is available",device.name); if ([device sendFile:filePath]) { [self log:[NSString stringWithFormat:@"Sending file: %@",filePath]]; [filesInTransit addObject:filePath]; } else { [self log:[NSString stringWithFormat:@"Error sending file: %@",filePath]]; } } else { NSLog(@"No idle devices"); } }
传输完成后,将调用此委托方法:
/* Responds to BluetoothPushDevice's TransferComplete notification */ - (void) transferStatusHandler: (NSNotification *) notification { NSString *status = [[notification userInfo] objectForKey:@"message"]; NSString *file = ((BluetoothPushDevice*)[notification object]).file; if ([status isEqualToString:kBluetoothTransferStatusComplete]) { if ([filesInTransit containsObject:file]) { NSFileManager *fileManager = [NSFileManager defaultManager]; NSError *error = nil; [fileManager removeItemAtPath:file error:&error]; if (error != nil) { [self log:[NSString stringWithFormat:@"**ERROR** File %@ could not be deleted (%@)",file,error.description]]; } [self log:[NSString stringWithFormat:@"File deleted: %@",file]]; [filesInTransit removeObject:file]; } else { [self log:[NSString stringWithFormat:@"**ERROR** filesInTransit array does not contain file %@",file]]; } } [self updateDeviceStatusDisplay]; }
我希望这可以帮助别人!