android - Kotlin 在运行时请求位置权限问题

Question

import android.Manifest
import android.bluetooth.BluetoothAdapter
import android.bluetooth.BluetoothManager
import android.content.Intent
import android.content.pm.PackageManager
import android.os.Build
import android.os.Bundle
import android.os.Looper
import android.util.Log
import android.widget.Toast
import androidx.annotation.RequiresApi
import androidx.appcompat.app.AlertDialog
import androidx.appcompat.app.AppCompatActivity
import androidx.core.app.ActivityCompat
import androidx.core.content.ContextCompat
import com.google.android.gms.location.*

@RequiresApi(Build.VERSION_CODES.JELLY_BEAN_MR2)
class DeviceScanActivity : AppCompatActivity() {
    //Getting BluetoothAdapter from BluetoothManager
    private fun PackageManager.missingSystemFeature(name: String): Boolean = !hasSystemFeature(name)
    private var fusedLocationProvider: FusedLocationProviderClient? = null
    private val locationRequest: LocationRequest =  LocationRequest.create().apply {
        interval = 30
        fastestInterval = 10
        priority = LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY
        maxWaitTime= 60
    }

    private var locationCallback: LocationCallback = object : LocationCallback() {
        override fun onLocationResult(locationResult: LocationResult) {
            val locationList = locationResult.locations
            if (locationList.isNotEmpty()) {
                val location = locationList.last()
                Toast.makeText(this@DeviceScanActivity, "Got Location: " + location.toString(), Toast.LENGTH_LONG).show()
            }
        }
    }

    private val bluetoothAdapter: BluetoothAdapter? by lazy(LazyThreadSafetyMode.NONE) {
        val bluetoothManager = getSystemService(BLUETOOTH_SERVICE) as BluetoothManager
        bluetoothManager.adapter
    }

    companion object {
        const val TAG: String = "Log"
        private const val MY_PERMISSIONS_REQUEST_LOCATION = 99

    }

    private val BluetoothAdapter.isDisabled: Boolean get() = !isEnabled
    private val REQUEST_ENABLE_BT = 1000


    //On memory
    @RequiresApi(Build.VERSION_CODES.LOLLIPOP)
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        Log.d(TAG, "DeviceScanActivity()")

        fusedLocationProvider = LocationServices.getFusedLocationProviderClient(this)
        checkLocationPermission()

        packageManager.takeIf {
            it.missingSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE)
        }?.also {
            Toast.makeText(this, "R.string.ble_not_supported", Toast.LENGTH_SHORT).show()
            finish()
        }
        bluetoothAdapter?.takeIf { it.isDisabled }?.apply {
            val enableBtIntent = Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE)
            startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT)
        }
        finish()
    }
    override fun onResume() {
        super.onResume()
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
            == PackageManager.PERMISSION_GRANTED) {

            fusedLocationProvider?.requestLocationUpdates(locationRequest, locationCallback, Looper.getMainLooper())
        }
    }

    override fun onPause() {
        super.onPause()
        if (ContextCompat.checkSelfPermission(this,
                Manifest.permission.ACCESS_FINE_LOCATION)
            == PackageManager.PERMISSION_GRANTED) {

            fusedLocationProvider?.removeLocationUpdates(locationCallback)
        }
    }

    private fun checkLocationPermission() {
        if (ActivityCompat.checkSelfPermission(
                this,
                Manifest.permission.ACCESS_FINE_LOCATION
            ) != PackageManager.PERMISSION_GRANTED
        ) {
            if(ActivityCompat.shouldShowRequestPermissionRationale(
                    this,
                    Manifest.permission.ACCESS_FINE_LOCATION
                )
            ) {
                AlertDialog.Builder(this)
                    .setTitle("Location Permission Needed")
                    .setMessage("This app needs the Location permission, please accept to use location functionality")
                    .setPositiveButton(
                        "OK"
                    ) { _, _ ->
                        //Prompt the user once explanation has been shown
                        requestLocationPermission()
                    }
                    .create()
                    .show()
            } else {
                requestLocationPermission()
            }
        }
    }

    private fun requestLocationPermission() {
        Log.d(TAG, "requestLocationPermission()")

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
            ActivityCompat.requestPermissions(
                this,
                arrayOf(
                    Manifest.permission.ACCESS_FINE_LOCATION,
                    Manifest.permission.ACCESS_BACKGROUND_LOCATION
                ),
                MY_PERMISSIONS_REQUEST_LOCATION
            )

        } else {
            ActivityCompat.requestPermissions(
                this,
                arrayOf(Manifest.permission.ACCESS_FINE_LOCATION),
                MY_PERMISSIONS_REQUEST_LOCATION
            )
        }
    }

    override fun onRequestPermissionsResult(
        requestCode: Int,
        permissions: Array<String>,
        grantResults: IntArray
    ) {
        Log.d(TAG, "result()")
        super.onRequestPermissionsResult(requestCode, permissions, grantResults)
        when (requestCode) {
            MY_PERMISSIONS_REQUEST_LOCATION -> {
                // If request is cancelled, the result arrays are empty.
                if (grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                    if (ContextCompat.checkSelfPermission(
                            this,
                            Manifest.permission.ACCESS_FINE_LOCATION
                        ) == PackageManager.PERMISSION_GRANTED
                    ) {
                        fusedLocationProvider?.requestLocationUpdates(
                            locationRequest,
                            locationCallback,
                            Looper.getMainLooper()
                        )
                    }

                } else {

                    Toast.makeText(this, "permission denied", Toast.LENGTH_LONG).show()
                }
                return
            }
        }
    }

}

要使用 BLE 观察和广告，我已在 Manifests 授予权限，并尝试在运行时手动请求。

但是，我的代码看起来不像在调用 onRequestPermissionResult，因为它没有在 LogCat 上显示“result()”，并且广告/观察无法正常工作。我的代码有什么问题？

标签： androidkotlinbluetooth-lowenergy