Question

出于某种原因，它仅在应用程序点击onPause时更新文本视图，例如当我点击主页按钮或多任务按钮时。有人可以帮我找出原因吗？

MainActivity.java：

import android.app.PendingIntent;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    private String lat, lon;
    private TextView longTextView, latTextView;
    LocationService locationService = new LocationService(this);
    private Intent intentService;
    private PendingIntent pendingIntent;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        latTextView = (TextView) findViewById(R.id.latitude_textview);
        longTextView = (TextView) findViewById(R.id.longitude_textview);  
    }

    @Override
    protected void onStart() {
        super.onStart();
        locationService.buildGoogleApiClient();
        locationService.apiConnect();

        if (latTextView != null && longTextView != null) {
            latTextView.setText( locationService.getLat());
            longTextView.setText( locationService.getLon());
            Toast.makeText(getApplicationContext(), " Actually got location", Toast.LENGTH_SHORT)
                    .show();
        } else {
            Toast.makeText(getApplicationContext(), "The shit was null fam", Toast.LENGTH_LONG)
                    .show();
        }
    }

    @Override
    protected void onStop() {
        super.onStop();
        locationService.apiDisconnect();   
    }  
}

LocationService.java：

import android.Manifest;
import android.app.Activity;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.location.Location;
import android.os.Bundle;
import android.os.IBinder;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.ActivityCompat;
import android.util.Log;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.FusedLocationProviderApi;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationServices;

import static com.google.android.gms.wearable.DataMap.TAG;

public class LocationService extends Service implements GoogleApiClient.ConnectionCallbacks,
        GoogleApiClient.OnConnectionFailedListener, LocationListener {

    // =============================================================  Variables

    Context context;
    Location mLastLocation;
    private GoogleApiClient mGoogleApiClient;
    private LocationRequest mLocationRequest;
    private String lat, lon;
    final static String[] LOCATION_PERMISSIONS = {Manifest.permission.ACCESS_COARSE_LOCATION, Manifest.permission.ACCESS_FINE_LOCATION};
    public static final long UPDATE_INTERVAL_IN_MILLISECONDS = 10000;
    public static final long UPDATE_FASTEST_INTERVAL_IN_MILLISECONDS = UPDATE_INTERVAL_IN_MILLISECONDS / 2;
    public static boolean isEnded = false;
    public static Boolean requestingLocationUpdates;
    protected String lastUpdateTime;

    final int GOOGLEAPI_REQUEST_CODE = 24;
    private FusedLocationProviderApi fusedLocationProviderApi = LocationServices.FusedLocationApi;    

    // =============================================================  Constructor    

    public LocationService(Context context) {
        this.context = context;
    }

    // =============================================================  Getters / Setters    

    public String getLon() {
        return lon;
    }

    public void setLon(String lon) {
        this.lon = lon;
    }

    public String getLat() {
        return lat;
    }

    public void setLat(String lat) {
        this.lat = lat;
    }    

    // ============================================================= Methods
    synchronized void buildGoogleApiClient() {
        mGoogleApiClient = new GoogleApiClient.Builder(context)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(LocationServices.API)
                .build();
    }

    public void apiConnect() {
        mGoogleApiClient.connect();
    }

    public void apiDisconnect() {
        mGoogleApiClient.disconnect();
    }

    void updateUI() {    
    }

    // ============================================================= Implemented Location Methods
    @Override
    public void onLocationChanged(Location location) {
        setLat(String.valueOf(location.getLatitude()));
        setLon(String.valueOf(location.getLongitude()));
    }

    @Override
    public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
        Log.i(TAG, "Connection failed: ConnectionResult.getErrorCode() = " + connectionResult.getErrorCode());
    }

    @Override
    public void onConnected(@Nullable Bundle bundle) {
        mLocationRequest = LocationRequest.create();
        mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
        mLocationRequest.setInterval(UPDATE_INTERVAL_IN_MILLISECONDS); // Sets Location to update every second
        mLocationRequest.setFastestInterval(UPDATE_FASTEST_INTERVAL_IN_MILLISECONDS); // The fastest location can update is every half-second

        startLocationUpdates();

        // TODO come back to this to see whats up
       /* mLastLocation = LocationServices.FusedLocationApi.getLastLocation(
                mGoogleApiClient);*/
        if (mLastLocation != null) {
            setLat(String.valueOf(mLastLocation.getLatitude()));
            setLon(String.valueOf(mLastLocation.getLongitude()));    
        }
    }

    @Override
    public void onConnectionSuspended(int i) {    
    }

    protected void startLocationUpdates() {
        /*if (!requestingLocationUpdates) {
            requestingLocationUpdates = true;*/

            if (ActivityCompat.checkSelfPermission(context, android.Manifest.permission.ACCESS_FINE_LOCATION)
                    != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(context, android.Manifest.permission.ACCESS_COARSE_LOCATION)
                    != PackageManager.PERMISSION_GRANTED) {
                ActivityCompat.requestPermissions((Activity) context, LOCATION_PERMISSIONS, GOOGLEAPI_REQUEST_CODE);

            } else {
                LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
            }
            Log.i(TAG, " startLocationUpdates===");
            isEnded = true;
        //}
    }    

    // ============================================================= Implemented Service Methods

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

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        // Within {@code onPause()}, we pause location updates, but leave the
        // connection to GoogleApiClient intact.  Here, we resume receiving
        // location updates if the user has requested them.
        Log.d("LOC", "Service init...");
        isEnded = false;
        requestingLocationUpdates = false;
        lastUpdateTime = "";
        buildGoogleApiClient();
        if (mGoogleApiClient.isConnected() && requestingLocationUpdates) {
            startLocationUpdates();
        }
        return Service.START_REDELIVER_INTENT;
    }
}

Answer 1

您没有在textview中更新位置的原因是因为您的代码没有办法让服务与活动进行通信。

如果您只想在活动位于前台时获取位置，请不要使用服务，请查看此google's example以获取位置并使用融合更新TextView位置提供商。

我不确定您为什么使用Service.Use 服务仅当您希望连续获取位置时，即使应用运行背景。为此，请使用提及here的任何一种方法来通知活动已获得新位置。LocalBroadcast将是您最好的选择。无论如何，在previous link中探索适合您的用例的最佳解决方案。

应用程序失焦时，位置仅更新TextView

1 个答案: