BluetoothLeScanner.startScan(scanCallback) не возвращает ноль ⇐ Android

[Гость]

Я пытаюсь подключить свой телефон к устройству Bluetooth. Я использую андроид 13. В моем файле scandevices я обнаружил проблему в этой строке bluetoothLeScaner.startScan(scanCallback). Я получаю исключение IllegalArgumentException: обратный вызов имеет значение null.
Menifest.xml

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build.gradle:

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android {
namespace 'com.example.sensor'
compileSdk 34

kotlinOptions {
jvmTarget = '17'
}

defaultConfig {
applicationId "com.example.sensor"
minSdk 31
targetSdk 33 //33
versionCode 1
versionName "1.0"

testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
vectorDrawables {
useSupportLibrary true
}
}

трассировка стека

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2024-03-12 13:36:00.288 25335-25335 PERMISSIONS             com.example.sensor                   D  Permission already granted: android.permission.BLUETOOTH
2024-03-12 13:36:00.289 25335-25335 PERMISSIONS             com.example.sensor                   D  Permission already granted: android.permission.BLUETOOTH_CONNECT
2024-03-12 13:36:00.290 25335-25335 PERMISSIONS             com.example.sensor                   D  Permission already granted: android.permission.ACCESS_COARSE_LOCATION
2024-03-12 13:36:00.290 25335-25335 PERMISSIONS             com.example.sensor                   D  Permission already granted: android.permission.ACCESS_FINE_LOCATION
2024-03-12 13:36:00.292 25335-25335 PERMISSIONS             com.example.sensor                   D  Permission already granted: android.permission.BLUETOOTH_ADMIN
2024-03-12 13:36:00.293 25335-25335 PERMISSIONS             com.example.sensor                   D  Permission already granted: android.permission.BLUETOOTH_SCAN
2024-03-12 13:36:00.294 25335-25335 PERMISSIONS             com.example.sensor                   D  Permission already granted: android.permission.BLUETOOTH_ADVERTISE
2024-03-12 13:36:00.294 25335-25335 PERMISSIONS             com.example.sensor                   D  All permissions are already granted

2024-03-12 13:36:00.299 25335-25335 BluetoothAdapter        com.example.sensor                   I  STATE_ON
2024-03-12 13:36:00.300 25335-25335 AndroidRuntime          com.example.sensor                   D  Shutting down VM
2024-03-12 13:36:00.304 25335-25335 AndroidRuntime          com.example.sensor                   E  FATAL EXCEPTION: main
Process: com.example.sensor, PID: 25335
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.sensor/com.example.sensor.MainActivity}: java.lang.IllegalArgumentException:  callback is null
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:4169)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4325)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:101)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2574)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loopOnce(Looper.java:226)
at android.os.Looper.loop(Looper.java:313)
at android.app.ActivityThread.main(ActivityThread.java:8779)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:604)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1067)
Caused by: java.lang.IllegalArgumentException:  callback is null
at android.bluetooth.le.BluetoothLeScanner.startScan(BluetoothLeScanner.java:136)
at com.example.sensor.data.ble.ScanDevices.run(ScanDevices.kt:40)
at com.example.sensor.data.ble.ScanDevices.(ScanDevices.kt:35)
at com.example.sensor.MainActivity.onCreate(MainActivity.kt:62)
at android.app.Activity.performCreate(Activity.java:8591)
at android.app.Activity.performCreate(Activity.java:8570)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1384)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:4150)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4325) 
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:101) 
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) 
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2574) 
at android.os.Handler.dispatchMessage(Handler.java:106) 
at android.os.Looper.loopOnce(Looper.java:226) 
at android.os.Looper.loop(Looper.java:313) 
at android.app.ActivityThread.main(ActivityThread.java:8779) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:604) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1067) 
2024-03-12 13:36:00.334 25335-25335 Process                 com.example.sensor                   I  Sending signal.  PID: 25335 SIG: 9

scandevice.kt

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@SuppressLint("MissingPermission")

class ScanDevices(
var bluetoothAdapter: BluetoothAdapter,
val context: Context

):Thread() {
val DEVICE_NAME = "WHEELSERV"
private var isScanning = false
private var bluetoothLeScaner = bluetoothAdapter.bluetoothLeScanner
private var device: BluetoothDevice? = null
private val latch = CountDownLatch(1);

init {
run()
}

override fun run() {
bluetoothLeScaner.startScan(scanCallback)
isScanning = true
latch.await()
val socket = device?.createL2capChannel(0)
try {
socket?.connect()
Log.d("CREATION", "yay connected ")
} catch (e: IOException) {
println("didnt connect to device")

}
}

val scanCallback = object : ScanCallback() {
override fun onScanResult(
callbackType: Int,
result: ScanResult
) {
super.onScanResult(callbackType, result)
if (result.device.name == DEVICE_NAME) {//filter
if (isScanning) {
isScanning = false
//bluetoothLeScaner.stopScan(scanCallback)
bluetoothAdapter.cancelDiscovery()
device = result.device
latch.countDown()
}
}
}

}
}

When debugging the code, I can see that bluetoothLeScanner is non-null. So then, I thought maybe it is an issue with permissions, so I tested it out in my MainActivity.kt. As you can see on the stack-trace and xml file, all permissions are setup, requested, and granted. I ran out of ideas on what the issue might be and would appreciate some advice on what I should test next.


Источник: https://stackoverflow.com/questions/781 ... rning-null