iOS蓝牙连接失败怎么办？Swift蓝牙开发教程详解

Swift中蓝牙开发的核心是CoreBluetooth框架，它允许iOS/macOS设备与低功耗蓝牙（BLE）设备交互,以下是完整开发流程：

环境配置与权限

// Info.plist 添加隐私描述
<key>NSBluetoothAlwaysUsageDescription</key>
<string>需要蓝牙权限连接设备</string>
<key>NSBluetoothPeripheralUsageDescription</key>
<string>与外设通信需开启蓝牙</string>

中心设备开发流程（iOS作为主机）

1. 初始化中心管理器

   import CoreBluetooth
   class BluetoothManager: NSObject, CBCentralManagerDelegate {
    private var centralManager: CBCentralManager!
    private var connectedPeripheral: CBPeripheral?
    override init() {
        super.init()
        centralManager = CBCentralManager(delegate: self, queue: nil)
    }
    func centralManagerDidUpdateState(_ central: CBCentralManager) {
        if central.state == .poweredOn {
            central.scanForPeripherals(withServices: nil, options: nil)
        }
    }
   }

2. 发现并连接外设

   func centralManager(_ central: CBCentralManager, 
                   didDiscover peripheral: CBPeripheral,
                   advertisementData: [String : Any], 
                   rssi RSSI: NSNumber) {
    // 根据设备名称或UUID过滤
    if peripheral.name?.contains("MyDevice") == true {
        connectedPeripheral = peripheral
        central.connect(peripheral, options: nil)
        central.stopScan()
    }
   }

3. 发现服务与特征值

   

   // 遵守CBPeripheralDelegate
   func peripheral(_ peripheral: CBPeripheral, didDiscoverServices error: Error?) {
    guard let services = peripheral.services else { return }
    for service in services {
        // 根据UUID过滤目标服务
        if service.uuid == CBUUID(string: "180A") {
            peripheral.discoverCharacteristics(nil, for: service)
        }
    }
   }

func peripheral(_ peripheral: CBPeripheral,
didDiscoverCharacteristicsFor service: CBService,
error: Error?) {

guard let characteristics = service.characteristics else { return }
for char in characteristics {
    // 订阅通知型特征
    if char.properties.contains(.notify) {
        peripheral.setNotifyValue(true, for: char)
    }
    // 发现描述符
    peripheral.discoverDescriptors(for: char)
}

4. 数据读写操作
```swift
// 写入数据到特征值
let data = Data([0x01, 0xA0])
peripheral.writeValue(data, for: char, type: .withResponse)
// 读取特征值
peripheral.readValue(for: char)
// 处理返回数据
func peripheral(_ peripheral: CBPeripheral,
                didUpdateValueFor characteristic: CBCharacteristic,
                error: Error?) {
    guard let data = characteristic.value else { return }
    // 解析数据逻辑...
}

外设模式开发（iOS作为从机）

class PeripheralManager: CBPeripheralManagerDelegate {
    private var peripheralManager: CBPeripheralManager!
    func setupService() {
        let serviceUUID = CBUUID(string: "1230")
        let charUUID = CBUUID(string: "1231")
        let characteristic = CBMutableCharacteristic(
            type: charUUID,
            properties: [.read, .notify],
            value: nil,
            permissions: .readable
        )
        let service = CBMutableService(type: serviceUUID, primary: true)
        service.characteristics = [characteristic]
        peripheralManager.add(service)
    }
    func peripheralManager(_ peripheral: CBPeripheralManager, 
                          didReceiveRead request: CBATTRequest) {
        // 响应读取请求
        request.value = Data("Response".utf8)
        peripheralManager.respond(to: request, withResult: .success)
    }
}

关键问题解决方案

1. 连接稳定性优化

   // 重连机制
   centralManager.connect(peripheral, options: [CBConnectPeripheralOptionNotifyOnDisconnectionKey: true])

// 断开回调处理
func centralManager(_ central: CBCentralManager,
didDisconnectPeripheral peripheral: CBPeripheral,
error: Error?) {
if error != nil {
central.connect(peripheral, options: nil)
}
}

2. 后台模式处理
```swift
// 在Capabilities中开启Background Modes -> Bluetooth
// 代码中声明后台任务ID
var backgroundTask: UIBackgroundTaskIdentifier?
backgroundTask = UIApplication.shared.beginBackgroundTask {
    // 清理操作
    UIApplication.shared.endBackgroundTask(backgroundTask!)
}

3. 数据分包处理

   // 大数据分包发送
   let chunkSize = 20
   for i in stride(from: 0, to: data.count, by: chunkSize) {
    let chunk = data.subdata(in: i..<min(i+chunkSize, data.count))
    peripheral.writeValue(chunk, for: char, type: .withoutResponse)
   }

性能优化技巧

• 使用CBCentralManagerScanOptionAllowDuplicatesKey控制扫描频率
• 连接前通过retrieveConnectedPeripherals检查已连接设备
• 特征值操作前验证peripheral.state == .connected

安全实践

// 配对请求处理
func peripheral(_ peripheral: CBPeripheral, 
                didWriteValueFor characteristic: CBCharacteristic, 
                error: Error?) {
    if error?.localizedDescription == "Not paired" {
        // 触发系统配对弹窗
        peripheral.readValue(for: characteristic)
    }
}

您在实际开发中遇到过哪些蓝牙连接问题？是否有特定场景（如医疗设备/IoT）需要深入探讨？欢迎在评论区分享您的经验或技术难点，我将针对性解答复杂数据传输、跨平台兼容等高级话题。