這里我們具體說明一下中心模式的應(yīng)用場景。主設(shè)備(手機(jī)去掃描連接外設(shè),發(fā)現(xiàn)外設(shè)服務(wù)和屬性,操作服務(wù)和屬性的應(yīng)用。一般來說,外設(shè)(藍(lán)牙設(shè)備,比如智能手環(huán)之類的東西), 會(huì)由硬件工程師開發(fā)好,并定義好設(shè)備提供的服務(wù),每個(gè)服務(wù)對于的特征,每個(gè)特征的屬性(只讀,只寫,通知等等),本文例子的業(yè)務(wù)場景,就是用一手機(jī)app去讀寫藍(lán)牙設(shè)備。
ios連接外設(shè)的代碼實(shí)現(xiàn)流程
建立中心角色
掃描外設(shè)(discover)
連接外設(shè)(connect)
掃描外設(shè)中的服務(wù)和特征(discover)
4.1 獲取外設(shè)的services
4.2 獲取外設(shè)的Characteristics,獲取Characteristics的值,獲取Characteristics的Descriptor和Descriptor的值
與外設(shè)做數(shù)據(jù)交互(explore and interact)
訂閱Characteristic的通知
斷開連接(disconnect)
準(zhǔn)備環(huán)境
1 xcode
2 開發(fā)證書和手機(jī)(藍(lán)牙程序需要使用使用真機(jī)調(diào)試,使用模擬器也可以調(diào)試,但是方法很蛋疼,我會(huì)放在最后說)
3 藍(lán)牙外設(shè)
實(shí)現(xiàn)步驟
1 導(dǎo)入CoreBluetooth頭文件,建立主設(shè)備管理類,設(shè)置主設(shè)備委托
#import
@interface ViewController : UIViewController<CBCentralManagerDelegate>
@interface ViewController (){
//系統(tǒng)藍(lán)牙設(shè)備管理對象,可以把他理解為主設(shè)備,通過他,可以去掃描和鏈接外設(shè)
CBCentralManager *manager;
//用于保存被發(fā)現(xiàn)設(shè)備
NSMutableArray *peripherals;
}
- (void)viewDidLoad {
[super viewDidLoad];
/*
設(shè)置主設(shè)備的委托,CBCentralManagerDelegate
必須實(shí)現(xiàn)的:
- (void)centralManagerDidUpdateState:(CBCentralManager *)central;//主設(shè)備狀態(tài)改變的委托,在初始化CBCentralManager的適合會(huì)打開設(shè)備,只有當(dāng)設(shè)備正確打開后才能使用
其他選擇實(shí)現(xiàn)的委托中比較重要的:
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI; //找到外設(shè)的委托
- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral;//連接外設(shè)成功的委托
- (void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error;//外設(shè)連接失敗的委托
- (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error;//斷開外設(shè)的委托
*/
//初始化并設(shè)置委托和線程隊(duì)列,最好一個(gè)線程的參數(shù)可以為nil,默認(rèn)會(huì)就main線程
manager = [[CBCentralManager alloc]initWithDelegate:self queue:dispatch_get_main_queue()];
2 掃描外設(shè)(discover),掃描外設(shè)的方法我們放在centralManager成功打開的委托中,因?yàn)橹挥性O(shè)備成功打開,才能開始掃描,否則會(huì)報(bào)錯(cuò)。
-(void)centralManagerDidUpdateState:(CBCentralManager *)central{
switch (central.state) {
case CBCentralManagerStateUnknown:
NSLog(@">>>CBCentralManagerStateUnknown");
break;
case CBCentralManagerStateResetting:
NSLog(@">>>CBCentralManagerStateResetting");
break;
case CBCentralManagerStateUnsupported:
NSLog(@">>>CBCentralManagerStateUnsupported");
break;
case CBCentralManagerStateUnauthorized:
NSLog(@">>>CBCentralManagerStateUnauthorized");
break;
case CBCentralManagerStatePoweredOff:
NSLog(@">>>CBCentralManagerStatePoweredOff");
break;
case CBCentralManagerStatePoweredOn:
NSLog(@">>>CBCentralManagerStatePoweredOn");
//開始掃描周圍的外設(shè)
/*
第一個(gè)參數(shù)nil就是掃描周圍所有的外設(shè),掃描到外設(shè)后會(huì)進(jìn)入
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI;
*/
[manager scanForPeripheralsWithServices:nil options:nil];
break;
default:
break;
}
}
//掃描到設(shè)備會(huì)進(jìn)入方法
-(void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI{
NSLog(@"當(dāng)掃描到設(shè)備:%@",peripheral.name);
//接下來可以連接設(shè)備
}
3 連接外設(shè)(connect)
//掃描到設(shè)備會(huì)進(jìn)入方法
-(void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI{
//接下連接我們的測試設(shè)備,如果你沒有設(shè)備,可以下載一個(gè)app叫l(wèi)ightbule的app去模擬一個(gè)設(shè)備
//這里自己去設(shè)置下連接規(guī)則,我設(shè)置的是P開頭的設(shè)備
if ([peripheral.name hasPrefix:@"P"]){
/*
一個(gè)主設(shè)備最多能連7個(gè)外設(shè),每個(gè)外設(shè)最多只能給一個(gè)主設(shè)備連接,連接成功,失敗,斷開會(huì)進(jìn)入各自的委托
- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral;//連接外設(shè)成功的委托
- (void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error;//外設(shè)連接失敗的委托
- (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error;//斷開外設(shè)的委托
*/
//找到的設(shè)備必須持有它,否則CBCentralManager中也不會(huì)保存peripheral,那么CBPeripheralDelegate中的方法也不會(huì)被調(diào)用!!
[peripherals addObject:peripheral];
//連接設(shè)備
[manager connectPeripheral:peripheral options:nil];
}
}
//連接到Peripherals-成功
- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral
{
NSLog(@">>>連接到名稱為(%@)的設(shè)備-成功",peripheral.name);
}
//連接到Peripherals-失敗
-(void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error
{
NSLog(@">>>連接到名稱為(%@)的設(shè)備-失敗,原因:%@",[peripheral name],[error localizedDescription]);
}
//Peripherals斷開連接
- (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error{
NSLog(@">>>外設(shè)連接斷開連接 %@: %@\n", [peripheral name], [error localizedDescription]);
}
有一點(diǎn)非常容易出錯(cuò),大家請注意。在 didDiscoverPeripheral這個(gè)委托中有這一行
//找到的設(shè)備必須持有它,否則CBCentralManager中也不會(huì)保存peripheral,那么CBPeripheralDelegate中的方法也不會(huì)被調(diào)用!!
[peripherals addObject:peripheral];
請?zhí)貏e注意,如果不保存,會(huì)影響到后面的方法執(zhí)行,這個(gè)地方很多人出錯(cuò),在我的藍(lán)牙交流群中每天幾乎都會(huì)因?yàn)檫@個(gè)問題導(dǎo)致無法連接和對外設(shè)后續(xù)的操作。
大家也可以看一下這個(gè)委托在xcode中的說明,重點(diǎn)看@discussion中的內(nèi)容,里面特別指出了需要retained對象。
/*!
@method centralManager:didDiscoverPeripheral:advertisementData:RSSI:
*
@param central The central manager providing this update.
@param peripheral A CBPeripheral object.
@param advertisementData A dictionary containing any advertisement and scan response data.
@param RSSI The current RSSI ofperipheral, in dBm. A value of 127 is reserved and indicates the RSSI
was not available.
*
@discussion This method is invoked while scanning, upon the discovery ofperipheralbycentral. A discovered peripheral must
be retained in order to use it; otherwise, it is assumed to not be of interest and will be cleaned up by the central manager. For
a list ofadvertisementDatakeys, see {@link CBAdvertisementDataLocalNameKey} and other similar constants.
*
@seealso CBAdvertisementData.h
*
*/
(void)centralManager:(CBCentralManager)central didDiscoverPeripheral:(CBPeripheral)peripheral advertisementData:(NSDictionary, id>)advertisementData RSSI:(NSNumber *)RSSI;
4掃描外設(shè)中的服務(wù)和特征(discover)
設(shè)備連接成功后,就可以掃描設(shè)備的服務(wù)了,同樣是通過委托形式,掃描到結(jié)果后會(huì)進(jìn)入委托方法。但是這個(gè)委托已經(jīng)不再是主設(shè)備的委托(CBCentralManagerDelegate),而是外設(shè)的委托(CBPeripheralDelegate),這個(gè)委托包含了主設(shè)備與外設(shè)交互的許多 回叫方法,包括獲取services,獲取characteristics,獲取characteristics的值,獲取characteristics的Descriptor,和Descriptor的值,寫數(shù)據(jù),讀rssi,用通知的方式訂閱數(shù)據(jù)等等。
4.1獲取外設(shè)的services
//連接到Peripherals-成功
- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral
{
NSLog(@">>>連接到名稱為(%@)的設(shè)備-成功",peripheral.name);
//設(shè)置的peripheral委托CBPeripheralDelegate
//@interface ViewController : UIViewController<CBCentralManagerDelegate,CBPeripheralDelegate>
[peripheral setDelegate:self];
//掃描外設(shè)Services,成功后會(huì)進(jìn)入方法:-(void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error{
[peripheral discoverServices:nil];
}
//掃描到Services
-(void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error{
//? NSLog(@">>>掃描到服務(wù):%@",peripheral.services);
if (error)
{
NSLog(@">>>Discovered services for %@ with error: %@", peripheral.name, [error localizedDescription]);
return;
}
for (CBService *service in peripheral.services) {
NSLog(@"%@",service.UUID);
//掃描每個(gè)service的Characteristics,掃描到后會(huì)進(jìn)入方法: -(void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error
[peripheral discoverCharacteristics:nil forService:service];
}
}
4.2獲取外設(shè)的Characteristics,獲取Characteristics的值,獲取Characteristics的Descriptor和Descriptor的值
//掃描到Characteristics
-(void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error{
if (error)
{
NSLog(@"error Discovered characteristics for %@ with error: %@", service.UUID, [error localizedDescription]);
return;
}
for (CBCharacteristic *characteristic in service.characteristics)
{
NSLog(@"service:%@ 的 Characteristic: %@",service.UUID,characteristic.UUID);
}
//獲取Characteristic的值,讀到數(shù)據(jù)會(huì)進(jìn)入方法:-(void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error
for (CBCharacteristic *characteristic in service.characteristics){
{
[peripheral readValueForCharacteristic:characteristic];
}
}
//搜索Characteristic的Descriptors,讀到數(shù)據(jù)會(huì)進(jìn)入方法:-(void)peripheral:(CBPeripheral *)peripheral didDiscoverDescriptorsForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error
for (CBCharacteristic *characteristic in service.characteristics){
[peripheral discoverDescriptorsForCharacteristic:characteristic];
}
}
//獲取的charateristic的值
-(void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error{
//打印出characteristic的UUID和值
//!注意,value的類型是NSData,具體開發(fā)時(shí),會(huì)根據(jù)外設(shè)協(xié)議制定的方式去解析數(shù)據(jù)
NSLog(@"characteristic uuid:%@? value:%@",characteristic.UUID,characteristic.value);
}
//搜索到Characteristic的Descriptors
-(void)peripheral:(CBPeripheral *)peripheral didDiscoverDescriptorsForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error{
//打印出Characteristic和他的Descriptors
NSLog(@"characteristic uuid:%@",characteristic.UUID);
for (CBDescriptor *d in characteristic.descriptors) {
NSLog(@"Descriptor uuid:%@",d.UUID);
}
}
//獲取到Descriptors的值
-(void)peripheral:(CBPeripheral *)peripheral didUpdateValueForDescriptor:(CBDescriptor *)descriptor error:(NSError *)error{
//打印出DescriptorsUUID 和value
//這個(gè)descriptor都是對于characteristic的描述,一般都是字符串,所以這里我們轉(zhuǎn)換成字符串去解析
NSLog(@"characteristic uuid:%@? value:%@",[NSString stringWithFormat:@"%@",descriptor.UUID],descriptor.value);
}
5 把數(shù)據(jù)寫到Characteristic中
//寫數(shù)據(jù)
-(void)writeCharacteristic:(CBPeripheral *)peripheral
characteristic:(CBCharacteristic *)characteristic
value:(NSData *)value{
//打印出 characteristic 的權(quán)限,可以看到有很多種,這是一個(gè)NS_OPTIONS,就是可以同時(shí)用于好幾個(gè)值,常見的有read,write,notify,indicate,知知道這幾個(gè)基本就夠用了,前連個(gè)是讀寫權(quán)限,后兩個(gè)都是通知,兩種不同的通知方式。
/*
typedef NS_OPTIONS(NSUInteger, CBCharacteristicProperties) {
CBCharacteristicPropertyBroadcast? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? = 0x01,
CBCharacteristicPropertyRead? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? = 0x02,
CBCharacteristicPropertyWriteWithoutResponse? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? = 0x04,
CBCharacteristicPropertyWrite? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? = 0x08,
CBCharacteristicPropertyNotify? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? = 0x10,
CBCharacteristicPropertyIndicate? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? = 0x20,
CBCharacteristicPropertyAuthenticatedSignedWrites? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? = 0x40,
CBCharacteristicPropertyExtendedProperties? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? = 0x80,
CBCharacteristicPropertyNotifyEncryptionRequired NS_ENUM_AVAILABLE(NA, 6_0)? ? ? ? = 0x100,
CBCharacteristicPropertyIndicateEncryptionRequired NS_ENUM_AVAILABLE(NA, 6_0)? ? = 0x200
};
*/
NSLog(@"%lu", (unsigned long)characteristic.properties);
//只有 characteristic.properties 有write的權(quán)限才可以寫
if(characteristic.properties & CBCharacteristicPropertyWrite){
/*
最好一個(gè)type參數(shù)可以為CBCharacteristicWriteWithResponse或type:CBCharacteristicWriteWithResponse,區(qū)別是是否會(huì)有反饋
*/
[peripheral writeValue:value forCharacteristic:characteristic type:CBCharacteristicWriteWithResponse];
}else{
NSLog(@"該字段不可寫!");
}
}
6 訂閱Characteristic的通知
//設(shè)置通知
-(void)notifyCharacteristic:(CBPeripheral *)peripheral
characteristic:(CBCharacteristic *)characteristic{
//設(shè)置通知,數(shù)據(jù)通知會(huì)進(jìn)入:didUpdateValueForCharacteristic方法
[peripheral setNotifyValue:YES forCharacteristic:characteristic];
}
//取消通知
-(void)cancelNotifyCharacteristic:(CBPeripheral *)peripheral
characteristic:(CBCharacteristic *)characteristic{
[peripheral setNotifyValue:NO forCharacteristic:characteristic];
}
7 斷開連接(disconnect)
//停止掃描并斷開連接
-(void)disconnectPeripheral:(CBCentralManager *)centralManager
peripheral:(CBPeripheral *)peripheral{
//停止掃描
[centralManager stopScan];
//斷開連接
[centralManager cancelPeripheralConnection:peripheral];
}
8 模擬器藍(lán)牙調(diào)試,慎用,最好還是用真機(jī)去調(diào)試。
由于在iPhone 4s之后的iOS才支持BLE,新一代的這些iOS設(shè)備又都不便宜,在做測試的時(shí)候,用iOS模擬器進(jìn)行調(diào)試,可以節(jié)約一些開發(fā)成本。怎么在iOS模擬器上調(diào)試BLE,
蘋果最初給出的說明是,支持BLE的mac機(jī)子上可以用模擬器進(jìn)行調(diào)試,并給出了一份技術(shù)文檔(傳送門),惡心的是,后來蘋果抽風(fēng),又把這份文檔移除,
并且把iOS 7.0的模擬器上對BLE的支持也移除掉了(難道是想讓大家多買設(shè)備測試?Apple sucks.)后面,網(wǎng)上搜了一下,解決辦法如下:
1. 買一個(gè)CSR藍(lán)牙4.0 USB適配器(某寶上大概30塊錢),在機(jī)子上插入該物(你懂的)
2. 在Terminal下敲入sudo nvram bluetoothHostControllerSwitchBehavior="never" , 重啟Mac。
3. 用XCode 4.6調(diào)試代碼,在iOS 6.1的模擬器上跑程序(用XCode 5.0跑iOS 7.0模擬器會(huì)拋異常,原因上面詳訴過了,Apple sucks,你懂的)
如何降低模擬器的IOS版本呢?
XCode->Preferences->Downloads里面有很多simulators你可以下載
選擇個(gè)6.1的下載好了
github,地址是:https://github.com/coolnameismy/demo,