iOS BLE 外设在调用 discoveryServices 后立即保持断开连接

Question

在为 iOS 开发 BLE 应用程序时，我总是在调用 discoveryServices 后立即断开连接。我正在使用 4 个完全相同的 BLE 设备 (OEM) 进行测试，并且在完全相同的两个设备上不断出现这种断开连接的情况。每次。我知道这些设备没问题，因为我也在 Android 上构建了相同的应用程序，并且使用相同的设备，所有 4 个设备都保持连接。这是使用 Titanium，但这里的一切都是在 iOS 中实现的。以下是相关的 iOS 代码:

- (void)centralManagerDidUpdateState:(CBCentralManager *)central

    {
TiLogMessage(@"[INFO] ===== %@ - centralManagerDidUpdateState: entry",self);

NSString *state = nil;

switch (central.state) {
    case CBCentralManagerStatePoweredOn:
        state = @"CentralManagerStatePoweredOn";
        break;

    case CBCentralManagerStateUnknown:
        state = @"CentralManagerStateUnknown";
        break;

    case CBCentralManagerStateResetting:
        state = @"CentralManagerStateResetting";
        break;

    case CBCentralManagerStateUnsupported:
        state = @"CentralManagerStateUnsupported";
        break;

    case CBCentralManagerStateUnauthorized:
        state = @"CentralManagerStateUnauthorized";
        break;

    case CBCentralManagerStatePoweredOff:
        state = @"CentralManagerStatePoweredOff";
        break;

    default:
        TiLogMessage(@"[INFO] ===== %@ - centralManagerDidUpdateState default -> break",self);
        break;
}

TiLogMessage(@"[INFO] ===== %@ - centralManagerDidUpdateState state changed to: %@",self, state);

NSDictionary *event = [NSDictionary dictionaryWithObjectsAndKeys:state, @"state", nil];

if ([self _hasListeners:@"centralManagerStateChange"]) {
    [self fireEvent:@"centralManagerStateChange" withObject: event];
}

TiLogMessage(@"[INFO] ===== %@ - centralManagerDidUpdateState: exit",self);

}

- (void) connectPeripheral:(id)args
    {
TiLogMessage(@"[INFO] ===== %@ : connectPeripheral - entry",self);

NSString* uuid = [[[args objectAtIndex:0] objectForKey:@"peripheral"] objectForKey: @"UUID"];

for (CBPeripheral *peripheral in self.discoveredPeripherals){
    if ([[peripheral.identifier UUIDString] isEqualToString:uuid]){
        TiLogMessage(@"[INFO] ===== %@ : connectPeripheral - device is %@",self, peripheral);
        TiLogMessage(@"[INFO] ===== %@ : connectPeripheral - attempting to connect to %@",self, peripheral.name);

        if (self.connectedPeripherals){
            TiLogMessage(@"[INFO] ===== %@ : connectedPeripheral - connectedPeripherals is ok...",self);

            if (![self.connectedPeripherals containsObject:peripheral]){
                TiLogMessage(@"[INFO] ===== %@ : connectPeripheral - device is not connected. Connecting.",self);

                if (centralManager.state == CBCentralManagerStatePoweredOn){
                    [centralManager connectPeripheral:peripheral options:nil];
                }
            }
            else{
                TiLogMessage(@"[INFO] ===== %@ : connectPeripheral - device is already connected. %@",self,peripheral);
            }
        }

    }
}

TiLogMessage(@"[INFO] ===== %@ : connectPeripheral - exit",self);

}

- (void) centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral

    {
TiLogMessage(@"[INFO] ===== %@ : didConnectPeripheral - entry",self);

if ( [manuallyDisconnectedPeripherals containsObject:[peripheral.identifier UUIDString]] ){
    [manuallyDisconnectedPeripherals removeObject:[peripheral.identifier UUIDString]];
}

if (![self.connectedPeripherals containsObject:peripheral]){

    [peripheral setDelegate:self];
    [self.connectedPeripherals addObject: peripheral];

    NSNumber *RSSI = 0;
    if (peripheral.RSSI != nil){
        RSSI = peripheral.RSSI;
    }

    NSDictionary *peripheralObj = [NSDictionary dictionaryWithObjectsAndKeys: [peripheral.identifier UUIDString], @"UUID",
                               peripheral.name, @"name",[NSNumber numberWithInteger:1], @"isConnected", RSSI, @"RSSI", nil];

    NSDictionary *event = [NSDictionary dictionaryWithObjectsAndKeys: peripheralObj, @"peripheral",
                       [peripheral.identifier UUIDString], @"UUID",nil];

    if ([self _hasListeners:@"didConnectPeripheral"]) {
        [self fireEvent:@"didConnectPeripheral" withObject: event];
    }
}

TiLogMessage(@"[INFO] ===== %@ : didConnectPeripheral - exit",self);

}

- (void) discoverServices:(id)args
    {
TiLogMessage(@"[INFO] ===== %@ : discoverServices - entry",self);

ENSURE_SINGLE_ARG(args,NSDictionary);
NSString *peripheralUUID = [[args objectForKey:@"peripheral"] objectForKey:@"UUID"];

TiLogMessage(@"[INFO] ===== %@ : discoverServices - for %@",self,peripheralUUID);

if (self.connectedPeripherals){
    for (CBPeripheral *peripheral in self.connectedPeripherals){
         if ([[peripheral.identifier UUIDString] isEqualToString:peripheralUUID]){
             TiLogMessage(@"[INFO] ===== %@ : discoverServices - , attempting to discover services for %@",self,peripheral);

             [peripheral discoverServices: [BLEServicesCBUUIDs count] > 0 ? BLEServicesCBUUIDs : nil];
         }
    }
}

TiLogMessage(@"[INFO] ===== %@ : discoverServices - exit",self);

}

Answer 1

您需要强烈保留 CBPeripheral 实例(您正在使用的实例)。 例如，在您的 View Controller 中，您需要有一个属性

@property(强，非原子)CBPeripheral *activePeripheral;

将找到的外围设备分配给 activePeripheral，然后您的员工进行操作(连接/发现/等...)

---

我认为使用像 CoreBluetooth 这样的框架并不是获得良好结果的好方法，您需要一些高级的、基于 block 的东西。这是我刚刚为您 promise 的一个图书馆 https://github.com/LGBluetooth/LGBluetooth

它将使蓝牙生活变得更加轻松。