android - 在我的应用程序从我的移动堆栈中销毁后，GPS 处于 Activity 状态

Question

我想在我的应用程序销毁表单堆栈后打开我的 GPS，下面是我的代码

主.java

public class LocationActivity extends Activity implements
    LocationListener,
    GoogleApiClient.ConnectionCallbacks,
    GoogleApiClient.OnConnectionFailedListener {

private static final String TAG = "LocationActivity";
private static final long INTERVAL = 1000 * 10;
private static final long FASTEST_INTERVAL = 1000 * 5;
Button btnFusedLocation;
TextView tvLocation;
LocationRequest mLocationRequest;
GoogleApiClient mGoogleApiClient;
Location mCurrentLocation;
String mLastUpdateTime;

protected void createLocationRequest() {
    mLocationRequest = new LocationRequest();
    mLocationRequest.setInterval(INTERVAL);
    mLocationRequest.setFastestInterval(FASTEST_INTERVAL);
    mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    Log.d(TAG, "onCreate ...............................");
    //show error dialog if GoolglePlayServices not available
    if (!isGooglePlayServicesAvailable()) {
        finish();
    }
    createLocationRequest();
    mGoogleApiClient = new GoogleApiClient.Builder(this)
            .addApi(LocationServices.API)
            .addConnectionCallbacks(this)
            .addOnConnectionFailedListener(this)
            .build();

    setContentView(R.layout.content_main);
    //tvLocation = (TextView) findViewById(R.id.tvLocation);

    btnFusedLocation = (Button) findViewById(R.id.btn_go);
    btnFusedLocation.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {
            updateUI();
        }
    });

}

@Override
public void onStart() {
    super.onStart();
    Log.d(TAG, "onStart fired ..............");
    mGoogleApiClient.connect();
}

@Override
public void onStop() {
    super.onStop();
    Log.d(TAG, "onStop fired ..............");
   // mGoogleApiClient.disconnect();
    //Log.d(TAG, "isConnected ...............: " + mGoogleApiClient.isConnected());
}

private boolean isGooglePlayServicesAvailable() {
    int status = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
    if (ConnectionResult.SUCCESS == status) {
        return true;
    } else {
        GooglePlayServicesUtil.getErrorDialog(status, this, 0).show();
        return false;
    }
}

@Override
public void onConnected(Bundle bundle) {
    Log.d(TAG, "onConnected - isConnected ...............: " + mGoogleApiClient.isConnected());
    startLocationUpdates();
}

protected void startLocationUpdates() {
    PendingResult<Status> pendingResult = LocationServices.FusedLocationApi.requestLocationUpdates(
            mGoogleApiClient, mLocationRequest, this);
    Log.d(TAG, "Location update started ..............: ");
}

@Override
public void onConnectionSuspended(int i) {

}

@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
    Log.d(TAG, "Connection failed: " + connectionResult.toString());
}

@Override
public void onLocationChanged(Location location) {
    Log.d(TAG, "Firing onLocationChanged..............................................");
    mCurrentLocation = location;
    mLastUpdateTime = DateFormat.getTimeInstance().format(new Date());
    updateUI();
}

private void updateUI() {
    Log.d(TAG, "UI update initiated .............");
    if (null != mCurrentLocation) {
        String lat = String.valueOf(mCurrentLocation.getLatitude());
        String lng = String.valueOf(mCurrentLocation.getLongitude());
        String ss="At Time: " + mLastUpdateTime + "\n" +
                "Latitude: " + lat + "\n" +
                "Longitude: " + lng + "\n" +
                "Accuracy: " + mCurrentLocation.getAccuracy() + "\n" +
                "Provider: " + mCurrentLocation.getProvider();
        Toast.makeText(LocationActivity.this,ss,Toast.LENGTH_LONG).show();
        /*tvLocation.setText("At Time: " + mLastUpdateTime + "\n" +
                "Latitude: " + lat + "\n" +
                "Longitude: " + lng + "\n" +
                "Accuracy: " + mCurrentLocation.getAccuracy() + "\n" +
                "Provider: " + mCurrentLocation.getProvider());*/
    } else {
        Log.d(TAG, "location is null ...............");
    }
}

@Override
protected void onPause() {
    super.onPause();
    startLocationUpdates();
    //stopLocationUpdates();
}

protected void stopLocationUpdates() {
    LocationServices.FusedLocationApi.removeLocationUpdates(
            mGoogleApiClient, this);
    Log.d(TAG, "Location update stopped .......................");
}

@Override
public void onResume() {
    super.onResume();
    if (mGoogleApiClient.isConnected()) {
        startLocationUpdates();
        Log.d(TAG, "Location update resumed .....................");
    }
}


}

从上面的代码来看，当我当时用移动后退按钮关闭我的应用程序时它工作正常，它仍然给我 GPS 位置但是当我执行下面的任务时，请参见图像

在上图中当我从我的移动堆栈关闭我的 GPS 应用程序时，我的 GPS 未处于 Activity 状态，所以我想在应用程序关闭后将其激活所以任何人都知道我怎样才能实现它？你所有的建议都是可观的

Answer 1

你好 friend 我用广播解决了我的问题引用我的代码

public class BrodActivity extends Activity {


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

private void initialize() {

    AlarmManager alarmManager=(AlarmManager) getSystemService(Context.ALARM_SERVICE);
    Intent intent = new Intent(BrodActivity.this, AlarmReceiver.class);
    PendingIntent pendingIntent = PendingIntent.getBroadcast(BrodActivity.this, 0, intent, 0);
    alarmManager.setRepeating(AlarmManager.RTC_WAKEUP,System.currentTimeMillis(),1000*60*1,
            pendingIntent);

}

}

AlarmReceiver.java

public class AlarmReceiver extends BroadcastReceiver
{

Location mCurrentLocation;
GPSTracker gps;
@Override
public void onReceive(Context context, Intent intent)
{
     gps = new GPSTracker(context);

            // check if GPS enabled
            if(gps.canGetLocation()){

                double latitude = gps.getLatitude();
                double longitude = gps.getLongitude();

                // \n is for new line
                Toast.makeText(context, "Your Location is - \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();
            }else{
                // can't get location
                // GPS or Network is not enabled
                // Ask user to enable GPS/network in settings
                gps.showSettingsAlert();
            }
    }
 }

GPSTracker.java

public class GPSTracker extends Service implements LocationListener {

private final Context mContext;

// flag for GPS status
boolean isGPSEnabled = false;

// flag for network status
boolean isNetworkEnabled = false;

// flag for GPS status
boolean canGetLocation = false;

Location location; // location
double latitude; // latitude
double longitude; // longitude

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

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

// Declaring a Location Manager
protected LocationManager locationManager;

public GPSTracker(Context context) {
    this.mContext = context;
    getLocation();
}

public Location getLocation() {
    try {
        locationManager = (LocationManager) mContext
                .getSystemService(LOCATION_SERVICE);

        // getting GPS status
        isGPSEnabled = locationManager
                .isProviderEnabled(LocationManager.GPS_PROVIDER);

        // getting network status
        isNetworkEnabled = locationManager
                .isProviderEnabled(LocationManager.NETWORK_PROVIDER);

        if (!isGPSEnabled && !isNetworkEnabled) {
            // no network provider is enabled
        } else {
            this.canGetLocation = true;
            if (isNetworkEnabled) {
                locationManager.requestLocationUpdates(
                        LocationManager.NETWORK_PROVIDER,
                        MIN_TIME_BW_UPDATES,
                        MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                Log.d("Network", "Network");
                if (locationManager != null) {
                    location = locationManager
                            .getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
                    if (location != null) {
                        latitude = location.getLatitude();
                        longitude = location.getLongitude();
                    }
                }
            }
            // if GPS Enabled get lat/long using GPS Services
            if (isGPSEnabled) {
                if (location == null) {
                    locationManager.requestLocationUpdates(
                            LocationManager.GPS_PROVIDER,
                            MIN_TIME_BW_UPDATES,
                            MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                    Log.d("GPS Enabled", "GPS Enabled");
                    if (locationManager != null) {
                        location = locationManager
                                .getLastKnownLocation(LocationManager.GPS_PROVIDER);
                        if (location != null) {
                            latitude = location.getLatitude();
                            longitude = location.getLongitude();
                        }
                    }
                }
            }
        }

    } catch (Exception e) {
        e.printStackTrace();
    }

    return location;
}

/**
 * Stop using GPS listener
 * Calling this function will stop using GPS in your app
 * */
public void stopUsingGPS(){
    if(locationManager != null){
        locationManager.removeUpdates(GPSTracker.this);
    }       
}

/**
 * Function to get latitude
 * */
public double getLatitude(){
    if(location != null){
        latitude = location.getLatitude();
    }

    // return latitude
    return latitude;
}

/**
 * Function to get longitude
 * */
public double getLongitude(){
    if(location != null){
        longitude = location.getLongitude();
    }

    // return longitude
    return longitude;
}

/**
 * Function to check GPS/wifi enabled
 * @return boolean
 * */
public boolean canGetLocation() {
    return this.canGetLocation;
}

/**
 * Function to show settings alert dialog
 * On pressing Settings button will lauch Settings Options
 * */
public void showSettingsAlert(){
    AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);

    // Setting Dialog Title
    alertDialog.setTitle("GPS is settings");

    // Setting Dialog Message
    alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");

    // On pressing Settings button
    alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog,int which) {
            Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
            mContext.startActivity(intent);
        }
    });

    // on pressing cancel button
    alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int which) {
        dialog.cancel();
        }
    });

    // Showing Alert Message
    alertDialog.show();
}

@Override
public void onLocationChanged(Location location) {
}

@Override
public void onProviderDisabled(String provider) {
}

@Override
public void onProviderEnabled(String provider) {
}

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

@Override
public IBinder onBind(Intent arg0) {
    return null;
    }

 }

AndroidManifest.xml

在 list 文件中注册接收器。

   <receiver
        android:name=".AlarmReceiver"
        android:exported="false">
    </receiver>

快乐编码!!!