java - 如何在运行时请求位置权限

Question

在 list 文件中，我添加了粗略和精细的权限，当我在装有 Android 6 的设备上运行时，什么也没有发生!我试试一切，但无法获取位置更新...

我做错了什么？

public class MainActivity extends AppCompatActivity implements LocationListener {

    LocationManager locationManager;
    String provider;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

        provider = locationManager.getBestProvider(new Criteria(), false);

        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // here to request the missing permissions, and then overriding
            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
            //                                          int[] grantResults)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            return;
        }
        Location location = locationManager.getLastKnownLocation(provider);

        if (location != null) {

            Log.i("Location Info", "Location achieved!");

        } else {

            Log.i("Location Info", "No location :(");

        }

    }


    @Override
    protected void onResume() {
        super.onResume();

        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // here to request the missing permissions, and then overriding
            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
            //                                          int[] grantResults)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            return;
        }
        locationManager.requestLocationUpdates(provider, 400, 1, this);

    }

    @Override
    protected void onPause() {
        super.onPause();

        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // here to request the missing permissions, and then overriding
            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
            //                                          int[] grantResults)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            return;
        }
        locationManager.removeUpdates(this);

    }

    @Override
    public void onLocationChanged(Location location) {

        Double lat = location.getLatitude();
        Double lng = location.getLongitude();

        Log.i("Location info: Lat", lat.toString());
        Log.i("Location info: Lng", lng.toString());

    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {

    }

    @Override
    public void onProviderEnabled(String provider) {

    }

    @Override
    public void onProviderDisabled(String provider) {

    }

    public void getLocation(View view) {

        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // here to request the missing permissions, and then overriding
            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
            //                                          int[] grantResults)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            return;
        }
        Location location = locationManager.getLastKnownLocation(provider);

        onLocationChanged(location);


    }

}

Answer 1

您需要在运行时实际请求位置权限(请注意代码中说明这一点的注释)。

更新了 Kotlin 和 API 31 (Android 12) 的后台位置:

从 API 30 开始，后台位置必须单独请求。此示例使用 targetSdk 31 和 compileSdk 31。请注意，可以将后台位置请求与 API 29 上的主要位置请求 bundle 在一起，但要做到这一点，您需要维护三个单独的代码路径。
将其分解为对 29 及以上的请求更容易。

确保在应用级别 gradle(撰写本文时为 18.0.0)中包含最新的定位服务:

implementation "com.google.android.gms:play-services-location:18.0.0"

在 list 中包含位置权限:

<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_BACKGROUND_LOCATION" />

这是一个简化的示例，可以处理大多数情况，但以简化的方式。在用户选择“不再询问”的情况下，在下次启动应用程序时，它将打开用户手动启用权限的设置。

完整的 Activity 代码:

import android.Manifest
import android.app.AlertDialog
import android.content.Intent
import android.content.pm.PackageManager
import android.net.Uri
import android.os.Build
import android.os.Bundle
import android.os.Looper
import android.provider.Settings
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import androidx.core.app.ActivityCompat
import androidx.core.content.ContextCompat
import com.google.android.gms.location.*


class MainActivity : AppCompatActivity() {

    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()) {
                //The last location in the list is the newest
                val location = locationList.last()
                Toast.makeText(
                    this@MainActivity,
                    "Got Location: " + location.toString(),
                    Toast.LENGTH_LONG
                )
                    .show()
            }
        }
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        fusedLocationProvider = LocationServices.getFusedLocationProviderClient(this)

        checkLocationPermission()
    }

    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
        ) {
            // Should we show an explanation?
            if (ActivityCompat.shouldShowRequestPermissionRationale(
                    this,
                    Manifest.permission.ACCESS_FINE_LOCATION
                )
            ) {
                // Show an explanation to the user *asynchronously* -- don't block
                // this thread waiting for the user's response! After the user
                // sees the explanation, try again to request the permission.
                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 {
                // No explanation needed, we can request the permission.
                requestLocationPermission()
            }
        } else {
            checkBackgroundLocation()
        }
    }

    private fun checkBackgroundLocation() {
        if (ActivityCompat.checkSelfPermission(
                this,
                Manifest.permission.ACCESS_BACKGROUND_LOCATION
            ) != PackageManager.PERMISSION_GRANTED
        ) {
            requestBackgroundLocationPermission()
        }
    }

    private fun requestLocationPermission() {
        ActivityCompat.requestPermissions(
            this,
            arrayOf(
                Manifest.permission.ACCESS_FINE_LOCATION,
            ),
            MY_PERMISSIONS_REQUEST_LOCATION
        )
    }

    private fun requestBackgroundLocationPermission() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
            ActivityCompat.requestPermissions(
                this,
                arrayOf(
                    Manifest.permission.ACCESS_BACKGROUND_LOCATION
                ),
                MY_PERMISSIONS_REQUEST_BACKGROUND_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
    ) {
        when (requestCode) {
            MY_PERMISSIONS_REQUEST_LOCATION -> {
                // If request is cancelled, the result arrays are empty.
                if (grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                    // permission was granted, yay! Do the
                    // location-related task you need to do.
                    if (ContextCompat.checkSelfPermission(
                            this,
                            Manifest.permission.ACCESS_FINE_LOCATION
                        ) == PackageManager.PERMISSION_GRANTED
                    ) {
                        fusedLocationProvider?.requestLocationUpdates(
                            locationRequest,
                            locationCallback,
                            Looper.getMainLooper()
                        )

                        // Now check background location
                        checkBackgroundLocation()
                    }

                } else {

                    // permission denied, boo! Disable the
                    // functionality that depends on this permission.
                    Toast.makeText(this, "permission denied", Toast.LENGTH_LONG).show()

                    // Check if we are in a state where the user has denied the permission and
                    // selected Don't ask again
                    if (!ActivityCompat.shouldShowRequestPermissionRationale(
                            this,
                            Manifest.permission.ACCESS_FINE_LOCATION
                        )
                    ) {
                        startActivity(
                            Intent(
                                Settings.ACTION_APPLICATION_DETAILS_SETTINGS,
                                Uri.fromParts("package", this.packageName, null),
                            ),
                        )
                    }
                }
                return
            }
            MY_PERMISSIONS_REQUEST_BACKGROUND_LOCATION -> {
                // If request is cancelled, the result arrays are empty.
                if (grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                    // permission was granted, yay! Do the
                    // location-related task you need to do.
                    if (ContextCompat.checkSelfPermission(
                            this,
                            Manifest.permission.ACCESS_FINE_LOCATION
                        ) == PackageManager.PERMISSION_GRANTED
                    ) {
                        fusedLocationProvider?.requestLocationUpdates(
                            locationRequest,
                            locationCallback,
                            Looper.getMainLooper()
                        )

                        Toast.makeText(
                            this,
                            "Granted Background Location Permission",
                            Toast.LENGTH_LONG
                        ).show()
                    }
                } else {

                    // permission denied, boo! Disable the
                    // functionality that depends on this permission.
                    Toast.makeText(this, "permission denied", Toast.LENGTH_LONG).show()
                }
                return

            }
        }
    }

    companion object {
        private const val MY_PERMISSIONS_REQUEST_LOCATION = 99
        private const val MY_PERMISSIONS_REQUEST_BACKGROUND_LOCATION = 66
    }
}

在 Android 10 (API 29) 上，用户可以选择在初始位置请求后授予后台位置:

在 Android 12 (API 31) 上它会执行相同的操作，但界面不同:

Java 中的原始答案:

这里是请求位置权限的测试和工作代码。

把这段代码放到Activity中:

public static final int MY_PERMISSIONS_REQUEST_LOCATION = 99;

public boolean checkLocationPermission() {
    if (ContextCompat.checkSelfPermission(this,
            Manifest.permission.ACCESS_FINE_LOCATION)
            != PackageManager.PERMISSION_GRANTED) {

        // Should we show an explanation?
        if (ActivityCompat.shouldShowRequestPermissionRationale(this,
                Manifest.permission.ACCESS_FINE_LOCATION)) {

            // Show an explanation to the user *asynchronously* -- don't block
            // this thread waiting for the user's response! After the user
            // sees the explanation, try again to request the permission.
            new AlertDialog.Builder(this)
                    .setTitle(R.string.title_location_permission)
                    .setMessage(R.string.text_location_permission)
                    .setPositiveButton(R.string.ok, new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialogInterface, int i) {
                            //Prompt the user once explanation has been shown
                            ActivityCompat.requestPermissions(MainActivity.this,
                                    new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
                                    MY_PERMISSIONS_REQUEST_LOCATION);
                        }
                    })
                    .create()
                    .show();


        } else {
            // No explanation needed, we can request the permission.
            ActivityCompat.requestPermissions(this,
                    new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
                    MY_PERMISSIONS_REQUEST_LOCATION);
        }
        return false;
    } else {
        return true;
    }
}

@Override
public void onRequestPermissionsResult(int requestCode,
                                       String permissions[], int[] grantResults) {
    switch (requestCode) {
        case MY_PERMISSIONS_REQUEST_LOCATION: {
            // If request is cancelled, the result arrays are empty.
            if (grantResults.length > 0
                    && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                // permission was granted, yay! Do the
                // location-related task you need to do.
                if (ContextCompat.checkSelfPermission(this,
                        Manifest.permission.ACCESS_FINE_LOCATION)
                        == PackageManager.PERMISSION_GRANTED) {

                    //Request location updates:
                    locationManager.requestLocationUpdates(provider, 400, 1, this);
                }

            } else {

                // permission denied, boo! Disable the
                // functionality that depends on this permission.

            }
            return;
        }

    }
}

然后在onCreate()中调用checkLocationPermission()方法:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    //.........

    checkLocationPermission();
}

然后，您可以完全按照问题中的方式使用 onResume() 和 onPause()。

这是一个更简洁的精简版:

@Override
protected void onResume() {
    super.onResume();
    if (ContextCompat.checkSelfPermission(this,
            Manifest.permission.ACCESS_FINE_LOCATION)
            == PackageManager.PERMISSION_GRANTED) {

        locationManager.requestLocationUpdates(provider, 400, 1, this);
    }
}

@Override
protected void onPause() {
    super.onPause();
    if (ContextCompat.checkSelfPermission(this,
            Manifest.permission.ACCESS_FINE_LOCATION)
            == PackageManager.PERMISSION_GRANTED) {

        locationManager.removeUpdates(this);
    }
}