如何在 Android 中获取位置及其温度？

Question

在这里，我使用“位置管理器”来查找当前位置，并使用“传感器管理器”来获取当前温度。当我使用“位置管理器”时，应用程序崩溃并显示此错误消息：

原因：java.lang.SecurityException：“网络”位置提供程序需要 ACCESS_COARSE_LOCATION 或 ACCESS_FINE_LOCATION 权限。

以下是“位置管理器”和“传感器管理器”的代码

**MainActivity.java**

    public class MainActivity extends AppCompatActivity implements SensorEventListener, LocationListener{

        protected LocationManager locationManager;
        protected LocationListener locationListener;
        protected Context context;

        private SensorManager mSensorManager;
        private Sensor mTemperature;
        private final static String NOT_SUPPORTED_MESSAGE = "Sorry, sensor not available for this device.";

        // The minimum distance to change Updates in meters
        private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 1; // 10 meters

        // The minimum time between updates in milliseconds
        private static final long MIN_TIME_BW_UPDATES = 1; // 1 minute

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

     locationManager = (LocationManager)context.getSystemService(Context.LOCATION_SERVICE);
            locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, MIN_DISTANCE_CHANGE_FOR_UPDATES, MIN_TIME_BW_UPDATES, this);
    }


    @Override
        public void onLocationChanged(Location location) {
            locationTextView.setText("Latitude:" + location.getLatitude() + ", Longitude:" + location.getLongitude());
        }

        @Override
        public void onProviderDisabled(String provider) {
            Log.d("Latitude","disable");
        }

        @Override
        public void onProviderEnabled(String provider) {
            Log.d("Latitude","enable");
        }

        @Override
        public void onStatusChanged(String provider, int status, Bundle extras) {
            Log.d("Latitude","status");
        }


       mSensorManager = (SensorManager)getSystemService(SENSOR_SERVICE);
        if(Build.VERSION.SDK_INT>=Build.VERSION_CODES.ICE_CREAM_SANDWICH){
            mTemperature= mSensorManager.getDefaultSensor(Sensor.TYPE_AMBIENT_TEMPERATURE); // requires API level 14.
        }
        if (mTemperature == null) {
            temperatureTextView.setText(NOT_SUPPORTED_MESSAGE);
        }


    @Override
    protected void onResume() {
        super.onResume();
        mSensorManager.registerListener(this, mTemperature, SensorManager.SENSOR_DELAY_NORMAL);
    }

    @Override
    protected void onPause() {
        super.onPause();
        mSensorManager.unregisterListener(this);
    }


    @Override
    public void onSensorChanged(SensorEvent event) {
        float ambient_temperature = event.values[0];
        temperatureTextView.setText(String.valueOf(ambient_temperature) + getResources().getString(R.string.celsius));
    }

    @Override
    public void onAccuracyChanged(Sensor sensor, int accuracy) {
        // Do something here if sensor accuracy changes.
    }

    }

Answer 1

将此添加到您的 android 清单文件中：

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

并且不要忘记请求位置权限。

Answer 2

您是否询问过运行时权限，并且在设置检查时是否为您的应用启用了位置和传感器。请求运行时权限以使用感觉和位置。

兼容所有 SDK 版本（android.permission.ACCESS_FINE_LOCATION 在 Android M 中成为危险权限，需要用户手动授予）。

在 Android M 以下的 Android 版本中，如果您在 AndroidManifest.xml 中添加这些权限，则 ContextCompat.checkSelfPermission(...) 始终返回 true)

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;
        }
    }
}
Then call the checkLocationPermission() method in onCreate():
@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);
    }
}

点击链接了解更多信息 https://developer.android.com/guide/topics/sensors/sensors_overview.html