Swift BLE调用discoverServices仅发现数组首个服务的问题

你的问题出在didDiscoverServices代理方法的for循环里的return语句——处理完第一个服务后就直接退出循环了，第二个服务根本没被遍历到。

看你原来的代码：

for service in services {
    // ...服务判断逻辑
    peripheral.discoverCharacteristics([...], for: service)
    return // 这里直接退出循环了！
}

只要把这个return删掉，循环就能遍历所有已发现的服务，自然就能同时处理BatteryService和NordicUARTService了。

另外可以优化特征发现的逻辑，针对不同服务只搜索对应的特征，避免无效操作：

修正后的完整代码：

func centralManager(_ central: CBCentralManager, didConnect peripheral: CBPeripheral) {
    if peripheral == myDevice {
        print("Connected to  \(peripheral.name ?? "") \(peripheral.identifier )\n\n")
        peripheral.discoverServices([bluetoothPeripheral.BatteryService, bluetoothPeripheral.NordicUARTService])
    }
}

// Delegate - Called when services are discovered
func peripheral(_ peripheral: CBPeripheral, didDiscoverServices error: Error?) {
    if let services = peripheral.services {
        for service in services {
            var targetCharacteristics: [CBUUID] = []
            
            if service.uuid == bluetoothPeripheral.BatteryService{
                print("Battery Service found")
                targetCharacteristics = [bluetoothPeripheral.BatteryLevelChar]
            } else if service.uuid == bluetoothPeripheral.NordicUARTService{
                print("UART Service found")
                targetCharacteristics = [bluetoothPeripheral.RxChar, bluetoothPeripheral.TxChar]
            }
            
            // 只搜索当前服务对应的特征
            if !targetCharacteristics.isEmpty {
                peripheral.discoverCharacteristics(targetCharacteristics, for: service)
            }
        }
    }
}

这样修改后，就能同时发现两个服务及其对应的特征，输出里也会同时出现"Battery Service found"和"UART Service found"的提示。

内容的提问来源于stack exchange，提问作者Intra Preneur