Android 检查 LocationManager 的权限

当我点击活动布局中的一个按钮时，我试图获得显示的 GPS 坐标。下面是单击按钮时调用的方法:

public void getLocation(View view) {
TextView tv = (TextView) findViewById(R.id.gps_coord_view);
LocationManager lm = (LocationManager) getSystemService(LOCATION_SERVICE);
Location loc = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
tv.setText("Latitude: " + loc.getLatitude() + "\nLongitude: " + loc.getLongitude());
}

我收到一个错误，说

调用需要可能被用户拒绝的权限。代码应该显式检查权限是否可用。

我已经在 AndroidManifest中授予了这些权限。当我在调用 lm.getLastKnownLocation之前添加以下内容时，这个错误会得到解决，应用程序也会编译:

if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED
&& checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
return;
}

然而，当我点击调用 getLocation 的按钮时，应用程序崩溃了。发生什么事了？有没有更好/更简单的方法来获取设备的 GPS 坐标？

274839 次浏览
小开

With Android API level (23), we are required to check for permissions. https://developer.android.com/training/permissions/requesting.html

I had your same problem, but the following worked for me and I am able to retrieve Location data successfully:

(1) Ensure you have your permissions listed in the Manifest: 

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

(2) Ensure you request permissions from the user: 

if ( ContextCompat.checkSelfPermission( this, android.Manifest.permission.ACCESS_COARSE_LOCATION ) != PackageManager.PERMISSION_GRANTED ) {


ActivityCompat.requestPermissions( this, new String[] {  android.Manifest.permission.ACCESS_COARSE_LOCATION  },
LocationService.MY_PERMISSION_ACCESS_COURSE_LOCATION );
}

(3) Ensure you use ContextCompat as this has compatibility with older API levels.

(4) In your location service, or class that initializes your LocationManager and gets the last known location, we need to check the permissions: 

if ( Build.VERSION.SDK_INT >= 23 &&
ContextCompat.checkSelfPermission( context, android.Manifest.permission.ACCESS_FINE_LOCATION ) != PackageManager.PERMISSION_GRANTED &&
ContextCompat.checkSelfPermission( context, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
return  ;
}

(5) This approach only worked for me after I included @TargetApi(23) at the top of my initLocationService method.

(6) I also added this to my gradle build: 

compile 'com.android.support:support-v4:23.0.1'

Here is my LocationService for reference: 

public class LocationService implements LocationListener  {


//The minimum distance to change updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 0; // 10 meters


//The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 0;//1000 * 60 * 1; // 1 minute


private final static boolean forceNetwork = false;


private static LocationService instance = null;


private LocationManager locationManager;
public Location location;
public double longitude;
public double latitude;




/**
* Singleton implementation
* @return
*/
public static LocationService getLocationManager(Context context)     {
if (instance == null) {
instance = new LocationService(context);
}
return instance;
}


/**
* Local constructor
*/
private LocationService( Context context )     {


initLocationService(context);
LogService.log("LocationService created");
}






/**
* Sets up location service after permissions is granted
*/
@TargetApi(23)
private void initLocationService(Context context) {




if ( Build.VERSION.SDK_INT >= 23 &&
ContextCompat.checkSelfPermission( context, android.Manifest.permission.ACCESS_FINE_LOCATION ) != PackageManager.PERMISSION_GRANTED &&
ContextCompat.checkSelfPermission( context, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
return  ;
}


try   {
this.longitude = 0.0;
this.latitude = 0.0;
this.locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);


// Get GPS and network status
this.isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
this.isNetworkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);


if (forceNetwork) isGPSEnabled = false;


if (!isNetworkEnabled && !isGPSEnabled)    {
// cannot get location
this.locationServiceAvailable = false;
}
//else
{
this.locationServiceAvailable = true;


if (isNetworkEnabled) {
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
if (locationManager != null)   {
location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
updateCoordinates();
}
}//end if


if (isGPSEnabled)  {
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);


if (locationManager != null)  {
location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
updateCoordinates();
}
}
}
} catch (Exception ex)  {
LogService.log( "Error creating location service: " + ex.getMessage() );


}
}




@Override
public void onLocationChanged(Location location)     {
// do stuff here with location object
}
}

I tested with an Android Lollipop device so far only. Hope this works for you.

小开

The last part of the error message you quoted states: ...with ("checkPermission") or explicitly handle a potential "SecurityException"

A much quicker/simpler way of checking if you have permissions is to surround your code with try { ... } catch (SecurityException e) { [insert error handling code here] }. If you have permissions, the 'try' part will execute, if you don't, the 'catch' part will.

小开

SIMPLE SOLUTION

I wanted to support apps pre api 23 and instead of using checkSelfPermission I used a try / catch

try {
location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
} catch (SecurityException e) {
dialogGPS(this.getContext()); // lets the user know there is a problem with the gps
}
小开

if you are working on dynamic permissions and any permission like ACCESS_FINE_LOCATION,ACCESS_COARSE_LOCATION giving error "cannot resolve method PERMISSION_NAME" in this case write you code with permission name and then rebuild your project this will regenerate the manifest(Manifest.permission) file.

小开

Use my custome class to check or request permisson

public class Permissons {


//Request Permisson
public static void Request_STORAGE(Activity act,int code)
{


ActivityCompat.requestPermissions(act, new
String[]{android.Manifest.permission.WRITE_EXTERNAL_STORAGE},code);
}
public static void Request_CAMERA(Activity act,int code)
{
ActivityCompat.requestPermissions(act, new
String[]{Manifest.permission.CAMERA},code);
}
public static void Request_FINE_LOCATION(Activity act,int code)
{
ActivityCompat.requestPermissions(act, new
String[]{Manifest.permission.ACCESS_FINE_LOCATION},code);
}
public static void Request_READ_SMS(Activity act,int code)
{
ActivityCompat.requestPermissions(act, new
String[]{Manifest.permission.READ_SMS},code);
}
public static void Request_READ_CONTACTS(Activity act,int code)
{
ActivityCompat.requestPermissions(act, new
String[]{Manifest.permission.READ_CONTACTS},code);
}
public static void Request_READ_CALENDAR(Activity act,int code)
{
ActivityCompat.requestPermissions(act, new
String[]{Manifest.permission.READ_CALENDAR},code);
}
public static void Request_RECORD_AUDIO(Activity act,int code)
{
ActivityCompat.requestPermissions(act, new
String[]{Manifest.permission.RECORD_AUDIO},code);
}


//Check Permisson
public static boolean Check_STORAGE(Activity act)
{
int result = ContextCompat.checkSelfPermission(act,android.Manifest.permission.WRITE_EXTERNAL_STORAGE);
return result == PackageManager.PERMISSION_GRANTED;
}
public static boolean Check_CAMERA(Activity act)
{
int result = ContextCompat.checkSelfPermission(act, Manifest.permission.CAMERA);
return result == PackageManager.PERMISSION_GRANTED;
}
public static boolean Check_FINE_LOCATION(Activity act)
{
int result = ContextCompat.checkSelfPermission(act, Manifest.permission.ACCESS_FINE_LOCATION);
return result == PackageManager.PERMISSION_GRANTED;
}
public static boolean Check_READ_SMS(Activity act)
{
int result = ContextCompat.checkSelfPermission(act, Manifest.permission.READ_SMS);
return result == PackageManager.PERMISSION_GRANTED;
}
public static boolean Check_READ_CONTACTS(Activity act)
{
int result = ContextCompat.checkSelfPermission(act, Manifest.permission.READ_CONTACTS);
return result == PackageManager.PERMISSION_GRANTED;
}
public static boolean Check_READ_CALENDAR(Activity act)
{
int result = ContextCompat.checkSelfPermission(act, Manifest.permission.READ_CALENDAR);
return result == PackageManager.PERMISSION_GRANTED;
}
public static boolean Check_RECORD_AUDIO(Activity act)
{
int result = ContextCompat.checkSelfPermission(act, Manifest.permission.RECORD_AUDIO);
return result == PackageManager.PERMISSION_GRANTED;
}
}

Example

if(!Permissons.Check_STORAGE(MainActivity.this))
{
//if not permisson granted so request permisson with request code
Permissons.Request_STORAGE(MainActivity.this,22);
}
小开

If you simply want to check for permissions (rather than request for permissions), I wrote a simple extension like so:

fun BaseActivity.checkPermission(permissionName: String): Boolean {
return if (Build.VERSION.SDK_INT >= 23) {
val granted =
ContextCompat.checkSelfPermission(this, permissionName)
granted == PackageManager.PERMISSION_GRANTED
} else {
val granted =
PermissionChecker.checkSelfPermission(this, permissionName)
granted == PermissionChecker.PERMISSION_GRANTED
}
}

Now, if I want to check for a permission I can simply pass in a permission like so:

checkPermission(Manifest.permission.READ_CONTACTS)

提交答案