java - 在请求权限之前 Android 应用程序已关闭？怎么解决呢？

Question

我第一次安装此应用程序时，当我启动 MapsActivity 时，系统会要求我提供权限，这是正常的。但问题是应用程序同时关闭。如何修改我的代码以保持应用程序打开，并且权限弹出窗口恰好重叠。非常感谢您的回答。

logcat 中的错误代码:

2020-02-02 11:17:01.340 11559-11574/? E/le.rsr_pechhlu: Unable to peek into adb socket due to error. Closing socket.: Connection reset by peer

2020-02-02 11:17:01.470 11559-11636/? E/AwareLog:AtomicFileUtils:readFileLines 文件不存在:android.util.AtomicFile@2f88384 2020-02-02 11:17:01.470 11559-11636/？ E/AwareLog:AtomicFileUtils:readFileLines 文件不存在:android.util.AtomicFile@7fa676d 2020-02-02 11:17:01.471 11559-11603/？ E/MemoryLeakMonitorManager: MemoryLeakMonitor.jar 不存在! 2020-02-02 11:17:10.787 11559-11559/com.example.rsr_pechhlup E/AndroidRuntime: 致命异常: main 进程:com.example.rsr_pechhlup，PID:11559 java.lang.RuntimeException:无法暂停 Activity {com.example.rsr_pechhlup/com.example.rsr_pechhlup.MapsActivity}:java.lang.NullPointerException:尝试调用虚拟方法 'void android.location.LocationManager.removeUpdates(android.location .LocationListener)' 位于空对象引用上 在 android.app.ActivityThread.performPauseActivityIfNeeded(ActivityThread.java:4742) 在 android.app.ActivityThread.performPauseActivity(ActivityThread.java:4691) 在 android.app.ActivityThread.handlePauseActivity(ActivityThread.java:4626) 在 android.app.servertransaction.PauseActivityItem.execute(PauseActivityItem.java:45) 在 android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:145) 在 android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:70) 在 android.app.ActivityThread$H.handleMessage(ActivityThread.java:2199) 在 android.os.Handler.dispatchMessage(Handler.java:112) 在 android.os.Looper.loop(Looper.java:216) 在 android.app.ActivityThread.main(ActivityThread.java:7625) 在 java.lang.reflect.Method.invoke( native 方法) 在 com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:524) 在 com.android.internal.os.ZygoteInit.main(ZygoteInit.java:987) 引起原因:java.lang.NullPointerException:尝试在空对象引用上调用虚拟方法“void android.location.LocationManager.removeUpdates(android.location.LocationListener)” 在 com.example.rsr_pechhlup.MapsActivity.onPause(MapsActivity.java:159) 在 android.app.Activity.performPause(Activity.java:7663) 在 android.app.Instrumentation.callActivityOnPause(Instrumentation.java:1536) 在 android.app.ActivityThread.performPauseActivityIfNeeded(ActivityThread.java:4726) 在 android.app.ActivityThread.performPauseActivity(ActivityThread.java:4691) 在 android.app.ActivityThread.handlePauseActivity(ActivityThread.java:4626) 在 android.app.servertransaction.PauseActivityItem.execute(PauseActivityItem.java:45) 在 android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:145) 在 android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:70) 在 android.app.ActivityThread$H.handleMessage(ActivityThread.java:2199) 在 android.os.Handler.dispatchMessage(Handler.java:112) 在 android.os.Looper.loop(Looper.java:216) 在 android.app.ActivityThread.main(ActivityThread.java:7625) 在 java.lang.reflect.Method.invoke( native 方法) 在 com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:524) 在 com.android.internal.os.ZygoteInit.main(ZygoteInit.java:987)

public class MapsActivity extends FragmentActivity implements LocationListener {

private GoogleMap googleMap; //google map is contained in the fragment work on it to change the position of the map and so on.
private Marker marker;
private Button buttonCallNow;
private RelativeLayout callPanelWrapper;
private static final int PERMS_CALL_ID = 1234; //permission identifier, unique identifier
private static final int REQUEST_PHONE_CALL = 4321;
private LocationManager locationManager; // Android manager service of android platform.
private SupportMapFragment mapFragment;
private Utils utils;
private PhoneCallListener phoneCallListener;
private boolean firstTime;
private String adresse;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_maps2);
    // Obtain the SupportMapFragment and get notified when the map is ready to be used.
     mapFragment= (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
}

/**
 * //When the activity comes back to the foreground, I have to subscribe to the different location information providers, so I will receive the new location information and I will be able to resynchronize my mapping on this location.
 */
@Override
protected void onResume() {
    super.onResume();
    checkPermissions();
    firstTime=true;
}

private void checkPermissions(){
    //For older versions of android we check that the ACCES_FINE_LOCATION and ACCES_COARSE_LOCATION permissions are enabled.
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)!= PackageManager.PERMISSION_GRANTED  && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION)!=PackageManager.PERMISSION_GRANTED){
        ActivityCompat.requestPermissions(this, new String[]{ Manifest.permission.ACCESS_FINE_LOCATION,  Manifest.permission.ACCESS_COARSE_LOCATION },PERMS_CALL_ID); //We must provide three parameters: it is the activity that requires the activation of these permissions (here it is this), then a table that specifies the set of permissions to allow. And we need a request code.
        return;
    }

    locationManager= (LocationManager) getSystemService(LOCATION_SERVICE);//I ask android to give me that service locationManager. LOCATION SERVICE comes inheritance FragmentActivity, which inherits from Context, which contains this constant.

    if(locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)){//If on this locationManager, a particular provider here : LocationManager.GPS_PROVIDER is allowed. If I have a GPS type sensor that is enabled, on the locationManager I will be able to subscribe to events.
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,1000,0,this);//This function requires the type of provider: LocationManager.GPS.it needs the frequency in milliseconds at which I want new location information(Here all the seconds).It needs to notify a person, who is going to receive this notification information, it's the MapsActivity, so this.
    }

    if(locationManager.isProviderEnabled(LocationManager.PASSIVE_PROVIDER)){//If on this locationManager, a particular provider here : LocationManager.PASIVE_PROVIDER is allowed. If I have a GPS type sensor that is enabled, on the locationManager I will be able to subscribe to events.
        locationManager.requestLocationUpdates(LocationManager.PASSIVE_PROVIDER,1000,0,this);//This function requires the type of provider: LocationManager.GPS.it needs the frequency in milliseconds at which I want new location information(Here all the seconds).It needs to notify a person, who is going to receive this notification information, it's the MapsActivity, so this.
    }

    if(locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER)){//If on this locationManager, a particular provider here : NETWORK is allowed. If I have a GPS type sensor that is enabled, on the locationManager I will be able to subscribe to events.
        locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER,1000,0,this);//This function requires the type of provider: LocationManager.GPS.it needs the frequency in milliseconds at which I want new location information(Here all the seconds).It needs to notify a person, who is going to receive this notification information, it's the MapsActivity, so this.
    }

    dispMap();
}


@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    if(requestCode==PERMS_CALL_ID){ //This method will be activated each time a permission request is made. And to know where I'm coming from I need the requestCode. This request is coupled with this requestCode here.
        checkPermissions(); //i call again chack permission do disp again pop-up permission.
    }
}

/**
 * //When my application leaves the foreground, I unsubscribe from the different providers of location information so as not to consume a lot of resources.
 */
@Override
protected void onPause() {
    super.onPause();
    //If the locationManager has been initialized, I make one of this, one of the earphone of all suppliers
    locationManager.removeUpdates(this);
}

private void dispMap(){
    mapFragment.getMapAsync(new OnMapReadyCallback() {
        @Override
        public void onMapReady(GoogleMap googleMap) {
            MapsActivity.this.googleMap=googleMap;

            marker = googleMap.addMarker(new MarkerOptions().position(new LatLng(43.799345,6.725426)));

        }
    });
}



/**
 * React each time new positioning information is calculated
 * @param location
 */
@Override
public void onLocationChanged(Location location) { //This location is obtained through the provider. Of course this can be any provider, GPS_PROVIDER is more accurate than PASSIVE_PROVIDER etc..
    double latitude= location.getLatitude();//I'm getting the latitude.
    double longitude=location.getLongitude();// I'm getting the longitude.
    Toast.makeText(this, "Location: " + latitude + "/" + longitude,Toast.LENGTH_SHORT).show();
    LatLng googleLocation=new LatLng(latitude,longitude);
    if(firstTime){
        googleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(googleLocation, 16.2f));
        adresse= Utils.getCompleteAddressString(latitude, longitude,this);
        BitmapDescriptor subwayBitmapDescriptor = BitmapDescriptorFactory.fromResource(R.drawable.map_marker);
        marker = googleMap.addMarker(new MarkerOptions().position(googleLocation).icon(subwayBitmapDescriptor).title(adresse));
        googleMap.setInfoWindowAdapter(new CustomInfoWindowAdapter(this));

    }
    firstTime=false;

    if(this.googleMap!=null){//If my map is correctly displayed
        adresse = Utils.getCompleteAddressString(latitude, longitude,this);
        googleMap.setInfoWindowAdapter(new CustomInfoWindowAdapter(this));
        marker.setTitle(adresse);
        marker.setPosition(googleLocation);
        marker.showInfoWindow();
    }
}

/**
 * To react to every change of state
 * @param provider
 * @param status
 * @param extras
 */
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {

}

/**
 * When a location provider is closed.
 * @param provider
 */
@Override
public void onProviderEnabled(String provider) {

}

/**
 * When a location provider is closed.
 * @param provider
 */
@Override
public void onProviderDisabled(String provider) {

}



public void btnBackClick(View view) {
    Intent myIntent = new Intent(this, HomeActivity.class);
    startActivity(myIntent);
}

public void btnCallMapclicked(View view) {
    callPanelWrapper.setVisibility(View.VISIBLE);
    buttonCallNow.setVisibility(View.GONE);

}

public void buttonFinalCallClicked(View view) {
    call();
}

public void popupClosedClicked(View view) {
    callPanelWrapper.setVisibility(View.GONE);
    buttonCallNow.setVisibility(View.VISIBLE);
}

}

}

Answer 1

我无法发表评论，因此将我的答案作为帖子转发。

您可能应该更多地描述您的问题，但您是否添加了 ACCESS_FINE_LOCATION 和

ACCESS_COARSE_LOCATION 到您的 list 文件？

编辑: 只需将 onPause 更改为以下内容:

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


      if(locationManager != null) // add this line to your code
         locationManager.removeUpdates(this);
}

原因: 当显示权限对话框时，您的 Activity onPause() 被调用，并且由于您尚未初始化位置管理器，因此它会抛出 NullPointerException。