似乎这个问题已“回答”here，但如果没有任何代码来展示他们的不同做法，我就不得不提出一个新问题。
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）。为了查看代码中是否有问题，我下载了Apple's sample code。在两个iOS设备上运行示例代码按预期工作，但是在将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
这里有什么问题？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]] }];
答案 0 :(得分：6)
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缓存已发现的状态并提供服务。没有以编程方式刷新/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连接可能会很糟糕。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。