Android.Kotlin.

你好，我很感激一些帮助了解线程如何在这里工作：）
我有一个BLE扫描器类。它的方法scan()用Dispatcher.IO运行所有东西。我设法确认它的代码不在主线程上运行。在它里面我创建了一个suspendCancellableCoroutine，在它里面我创建了一个ScanCallback。我假设回调的方法会在创建回调的同一个线程上运行。但它不是-它运行在主线程上，可能会阻塞UI。

问题：有没有办法确保ScanCallback'的方法，如onScanResult和onScanFailed运行在同一个线程上，其余的FakeScaner.scan()方法运行在同一个线程上？

原因：在某些情况下，我需要停止扫描仪，睡眠几秒钟，然后重新启动它。我设法做了一个变通方案，但我仍然想弄清楚为什么它能正常工作，以及如果可能的话如何改变它：）

class FakeScanner(
    private val context: Context,
    private val ioDispatcher: CoroutineDispatcher = Dispatchers.IO) {
    private val bluetoothAdapter: BluetoothAdapter by lazy {
        val bluetoothManager = context.getSystemService(Context.BLUETOOTH_SERVICE) as BluetoothManager
        requireNotNull(bluetoothManager.adapter)
    }
    suspend fun scan(timeout: Duration?): Map<MyDevice, SignalStrength> =
        withContext(ioDispatcher) {
            if (Looper.myLooper() == Looper.getMainLooper()) {
                Log.d(TAG, "This is running MAIN thread")
            } else {
                Log.d(TAG, "This is running NOT on MAIN thread")
            }
            /**
             * Some code here
             */
            suspendCancellableCoroutine { cont ->
                val bleDevices = mutableMapOf<BluetoothDevice, SignalStrength>()
                val scanCallback = object : ScanCallback() {
                    @Synchronized
                    override fun onScanResult(callbackType: Int, result: ScanResult?) {
                        if (Looper.myLooper() == Looper.getMainLooper()) {
                            Log.d(TAG, "This is running MAIN thread")
                        } else {
                            Log.d(TAG, "This is running NOT on MAIN thread")
                        }
                        try {
                            result?.device?.let {
                                bleDevices.put(it, SignalStrength(result.rssi))
                            }
                        } catch (t: Throwable) {
                            if (cont.isActive) { cont.resumeWithException(t) }
                        }
                    }
                    @Synchronized
                    override fun onScanFailed(errorCode: Int) {
                        try {
                            // Some logic about scan attempt limits..
                            when (errorCode) {
                                SCAN_FAILED_ALREADY_STARTED -> { /* Restart scanner after delay */ }
                                else -> { /* Logic about other error codes */ }
                            }
                        } catch (t: Throwable) {
                            if (cont.isActive) { cont.resumeWithException(t) }
                        }
                    }
                }
                try {
                    // Start scanning
                } catch (t: Throwable) {
                    if (cont.isActive) {
                        cont.resumeWithException(t)
                    }
                }
                cont.invokeOnCancellation {
                    try {
                        // Stop scanner here
                    } catch (t: SecurityException) {
                        // Nothing to do here
                    }
                }
            }
        }
}

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