藍牙開發<coreBluetooth/CoreBluetooth.h>

/*
 建立中心設備
 掃描外設（Discover Peripheral）
 連接外設（Connect Peripheral）
 掃描外設中的服務和特征（Discover Services And Charateristics）
 利用特征與外設做數據交互（Explore And Interact）
 斷開連接（Disconnect）
 */

#import "ViewController.h"
#import <coreBluetooth/CoreBluetooth.h>

@interface ViewController ()<CBCentralManagerDelegate, CBPeripheralDelegate>

@property (nonatomic, strong) CBCentralManager *mgr;
/** 發現的外設數組*/
@property (nonatomic, strong) NSMutableArray *peripheralArray;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    // 1.建立中心設備
    // queque:如果說你傳空，在主隊列
    self.mgr = [[CBCentralManager alloc] initWithDelegate:self queue:nil];
    
    // 2.掃描外設
    
}

- (void)viewWillDisappear:(BOOL)animated {
    [super viewWillDisappear:animated];
    
    // 最後一步，斷開連接
    [self.mgr stopScan];
}

#pragma CBCentralManagerDelegate
/*
state:
CBManagerStateUnknown = 0, 未知
CBManagerStateResetting, 重置
CBManagerStateUnsupported, 不支持
CBManagerStateUnauthorized, 未經授權
CBManagerStatePoweredOff, 沒有啟動
CBManagerStatePoweredOn, 開啟
 */
- (void)centralManagerDidUpdateState:(CBCentralManager *)central {
    
    NSLog(@"state = %zd", central.state);
    // 藍牙開啟
    if (central.state == CBManagerStateUnknown) {
        
        NSLog(@"未知的藍牙");
    }
    if (central.state == CBManagerStatePoweredOn) {
        
        // 2.掃描外設
        [self.mgr scanForPeripheralsWithServices:nil options:nil];
    }
}

/**
 3.連接外設（Connect Peripheral）
 @param peripheral 外設
 @param advertisementData 相關的二進位數據
 @param RSSI 信號強度
 */
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary<NSString *,id> *)advertisementData RSSI:(NSNumber *)RSSI {
    
    // 1.記錄外設，必須要有數組進來行存儲
    if ([self.peripheralArray containsObject:peripheral]) {
        
        [self.peripheralArray addObject:peripheral];
    }
    // 2.隱藏步驟，tableview表格列表（省略了）
    // 3.連接外圍設備
    [self.mgr connectPeripheral:peripheral options:nil];
    // 4.設置外設的代理
    peripheral.delegate = self;
    
    
}

// 連接到外設之後，會調用這個代理方法
- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral {
    
    // 掃描服務
    // 傳nil代表掃描所有服務
    [peripheral discoverServices:nil];
    
}

#pragma CBPeripheralDelegate
// 外設掃描裡面的服務
- (void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error {
    
    // 獲取外設的服務
    for (CBService *service in peripheral.services) {
        
        if ([service.UUID.UUIDString isEqualToString:@"123"]) {
            // uuid一致，那就開始掃描特征
            [peripheral discoverCharacteristics:nil forService:service];
            
        }
    }
}

// 當發現到特征的時候會調用
- (void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error {
    
    //
    for (CBCharacteristic *characteristic in service.characteristics) {
        
        if ([characteristic.UUID.UUIDString isEqualToString:@"123456"]) {
            
//            [peripheral readValueForDescriptor:<#(nonnull CBDescriptor *)#>];
            
//            [peripheral writeValue:<#(nonnull NSData *)#> forDescriptor:<#(nonnull CBDescriptor *)#>];
        }
    }
}



- (NSMutableArray *)peripheralArray {
    
    if (!_peripheralArray) {
        
        _peripheralArray = [NSMutableArray array];
    }
    return _peripheralArray;
}