似乎这个问题被“回答”了
here,但没有任何代码来表明他们做了不同的事情,我不得不问一个新问题.
我有自己的代码具有相同的行为,在OS X上使用Core Bluetooth的CBCentralManager扫描特定的CBUUID并没有发现一个iOS设备充当CBPeripheralManager的外围设备(除非它及其服务先前已被发现).为了查看我的代码是否有问题,我下载了Apple’s sample code.在两台iOS设备上运行示例代码按预期工作,但是当将CBCentralManager代码复制到OS X应用程序时,它无法找到iOS设备.
我已经为OS X应用程序上传了一个Xcode项目,它是hosted on WikiUpload,因为它似乎是最不狡猾的.如果人们愿意,还有a copy on my hosting.
这是OS X项目中的AppDelegate.m代码(CoreBluetooth框架在项目中链接):
#import <CoreBluetooth/CoreBluetooth.h> @interface AppDelegate () <CBCentralManagerDelegate,CBPeripheralDelegate> @property (strong,nonatomic) CBCentralManager *centralManager; @property (strong,nonatomic) CBPeripheral *discoveredPeripheral; @property (strong,nonatomic) NSMutableData *data; @property (weak) IBOutlet NSWindow *window; @end @implementation AppDelegate @synthesize centralManager = _centralManager,discoveredPeripheral = _discoveredPeripheral,data = _data; - (void)applicationDidFinishLaunching:(NSNotification *)aNotification { // Insert code here to initialize your application // Start up the CBCentralManager _centralManager = [[CBCentralManager alloc] initWithDelegate:self queue:nil]; // And somewhere to store the incoming data _data = [[NSMutableData alloc] init]; } - (void)applicationWillTerminate:(NSNotification *)aNotification { // Insert code here to tear down your application } #pragma mark - Central Methods /** centralManagerDidUpdateState is a required protocol method. * Usually,you'd check for other states to make sure the current device supports LE,is powered on,etc. * In this instance,we're just using it to wait for CBCentralManagerStatePoweredOn,which indicates * the Central is ready to be used. */ - (void)centralManagerDidUpdateState:(CBCentralManager *)central { if (central.state != CBCentralManagerStatePoweredOn) { // In a real app,you'd deal with all the states correctly return; } // The state must be CBCentralManagerStatePoweredOn... // ... so start scanning [self scan]; } /** Scan for peripherals - specifically for our service's 128bit CBUUID */ - (void)scan { // This brings up nothing,unlike on iOS where it finds the device straight away [self.centralManager scanForPeripheralsWithServices:@[[CBUUID UUIDWithString:TRANSFER_SERVICE_UUID]] options:@{ CBCentralManagerScanOptionAllowDuplicatesKey : @YES }]; // [self.centralManager scanForPeripheralsWithServices:nil // options:@{ CBCentralManagerScanOptionAllowDuplicatesKey : @YES }]; NSLog(@"Scanning started"); } /** This callback comes whenever a peripheral that is advertising the TRANSFER_SERVICE_UUID is discovered. * We check the RSSI,to make sure it's close enough that we're interested in it,and if it is,* we start the connection process */ - (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI { NSLog(@"Discovered %@ at %@",peripheral.name,RSSI); //Took out RSSI check if (self.discoveredPeripheral != peripheral) { // Save a local copy of the peripheral,so CoreBluetooth doesn't get rid of it self.discoveredPeripheral = peripheral; // And connect NSLog(@"Connecting to peripheral %@",peripheral); [self.centralManager connectPeripheral:peripheral options:nil]; } } /** If the connection fails for whatever reason,we need to deal with it. */ - (void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error { NSLog(@"Failed to connect to %@. (%@)",peripheral,[error localizedDescription]); [self cleanup]; } /** We've connected to the peripheral,now we need to discover the services and characteristics to find the 'transfer' characteristic. */ - (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral { NSLog(@"Peripheral Connected"); // Stop scanning [self.centralManager stopScan]; NSLog(@"Scanning stopped"); // Clear the data that we may already have [self.data setLength:0]; // Make sure we get the discovery callbacks peripheral.delegate = self; // Search only for services that match our UUID [peripheral discoverServices:@[[CBUUID UUIDWithString:TRANSFER_SERVICE_UUID]]]; } /** The Transfer Service was discovered */ - (void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error { if (error) { NSLog(@"Error discovering services: %@",[error localizedDescription]); [self cleanup]; return; } // Discover the characteristic we want... // Loop through the newly filled peripheral.services array,just in case there's more than one. for (CBService *service in peripheral.services) { [peripheral discoverCharacteristics:@[[CBUUID UUIDWithString:TRANSFER_CHARACTERISTIC_UUID]] forService:service]; } } /** The Transfer characteristic was discovered. * Once this has been found,we want to subscribe to it,which lets the peripheral know we want the data it contains */ - (void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error { // Deal with errors (if any) if (error) { NSLog(@"Error discovering characteristics: %@",[error localizedDescription]); [self cleanup]; return; } // Again,we loop through the array,just in case. for (CBCharacteristic *characteristic in service.characteristics) { // And check if it's the right one if ([characteristic.UUID isEqual:[CBUUID UUIDWithString:TRANSFER_CHARACTERISTIC_UUID]]) { // If it is,subscribe to it [peripheral setNotifyValue:YES forCharacteristic:characteristic]; } } // Once this is complete,we just need to wait for the data to come in. } /** This callback lets us know more data has arrived via notification on the characteristic */ - (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error { if (error) { NSLog(@"Error discovering characteristics: %@",[error localizedDescription]); return; } NSString *stringFromData = [[NSString alloc] initWithData:characteristic.value encoding:NSUTF8StringEncoding]; // Have we got everything we need? if ([stringFromData isEqualToString:@"EOM"]) { // We have,so show the data,//[self.textview setText:[[NSString alloc] initWithData:self.data encoding:NSUTF8StringEncoding]]; NSLog(@"Text: %@",[[NSString alloc] initWithData:self.data encoding:NSUTF8StringEncoding]); // Cancel our subscription to the characteristic [peripheral setNotifyValue:NO forCharacteristic:characteristic]; // and disconnect from the peripehral [self.centralManager cancelPeripheralConnection:peripheral]; } // Otherwise,just add the data on to what we already have [self.data appendData:characteristic.value]; // Log it NSLog(@"Received: %@",stringFromData); } /** The peripheral letting us know whether our subscribe/unsubscribe happened or not */ - (void)peripheral:(CBPeripheral *)peripheral didUpdateNotificationStateForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error { if (error) { NSLog(@"Error changing notification state: %@",error.localizedDescription); } // Exit if it's not the transfer characteristic if (![characteristic.UUID isEqual:[CBUUID UUIDWithString:TRANSFER_CHARACTERISTIC_UUID]]) { return; } // Notification has started if (characteristic.isNotifying) { NSLog(@"Notification began on %@",characteristic); } // Notification has stopped else { // so disconnect from the peripheral NSLog(@"Notification stopped on %@. Disconnecting",characteristic); [self.centralManager cancelPeripheralConnection:peripheral]; } } /** Once the disconnection happens,we need to clean up our local copy of the peripheral */ - (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error { NSLog(@"Peripheral Disconnected"); self.discoveredPeripheral = nil; // We're disconnected,so start scanning again [self scan]; } /** Call this when things either go wrong,or you're done with the connection. * This cancels any subscriptions if there are any,or straight disconnects if not. * (didUpdateNotificationStateForCharacteristic will cancel the connection if a subscription is involved) */ - (void)cleanup { // Don't do anything if we're not connected if (!self.discoveredPeripheral.isConnected) { return; } // See if we are subscribed to a characteristic on the peripheral if (self.discoveredPeripheral.services != nil) { for (CBService *service in self.discoveredPeripheral.services) { if (service.characteristics != nil) { for (CBCharacteristic *characteristic in service.characteristics) { if ([characteristic.UUID isEqual:[CBUUID UUIDWithString:TRANSFER_CHARACTERISTIC_UUID]]) { if (characteristic.isNotifying) { // It is notifying,so unsubscribe [self.discoveredPeripheral setNotifyValue:NO forCharacteristic:characteristic]; // And we're done. return; } } } } } } // If we've got this far,we're connected,but we're not subscribed,so we just disconnect [self.centralManager cancelPeripheralConnection:self.discoveredPeripheral]; }
在AppDelegate.h中有UUID定义:
#ifndef LE_Transfer_TransferService_h #define LE_Transfer_TransferService_h #define TRANSFER_SERVICE_UUID @"E20A39F4-73F5-4BC4-A12F-17D1AD07A961" #define TRANSFER_CHARACTERISTIC_UUID @"08590F7E-DB05-467E-8757-72F6FAEB13D4" #endif
这有什么问题?根据上面的链接问题,服务必须是广告包的一部分,但据我所知,这正是iOS外设正在做的事情
[self.peripheralManager startAdvertising:@{ CBAdvertisementDataServiceUUIDsKey : @[[CBUUID UUIDWithString:TRANSFER_SERVICE_UUID]] }];
解决方法
CoreBluetooth可能非常令人沮丧.这里有几件事要尝试:
#1:已连接的外围设备停止广告.如果您成功连接到外围设备,则需要重新开始广告.
#2:iOS缓存已发现状态和提供的服务.没有编程方式来刷新/清除缓存.尝试在iOS设备和Mac上禁用BT并重新启用它.然后尝试另一个连接.
#3:您的UUID存在问题.尝试扫描UUID参数设置为nil的外围设备.然后,您应该发现范围内的所有外围设备.
#4:如果Wifi打开,Mac上的BT连接可能很挑剔.尝试在Mac上禁用Wifi,然后重试.我发现BTLE在启用Wifi时完全无法使用,因此我在MacBook上执行任何BTLE开发时都必须使用以太网.