将 gps 坐标从服务内的 onLocationChanged 发送到 UI 的最佳方法是什么？

Question

我创建了一个实现 LocationListener 并使用融合位置提供程序的服务。我的问题是我想将 gps 坐标从服务内的 onLocationChanged 发送到更新 UI 的活动。我已经注册了一个 BroadcastReceiver 来将数据发送到活动，但是因为更新发生得非常频繁（每秒），所以 UI 不会一直更新。大多数坐标从未出现在 UI 中。我的问题是将数据从服务内部的 onLocationChanged 发送到活动的最佳方式是什么？

这是我的代码：

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

LocationClient locationclient;
LocationRequest locationrequest;
private static final String TAG = "LocationService";
public static final String BROADCAST_ACTION =  "com.example.fusedlocation.displayevent";
Intent intent;

@Override
public void onCreate() {
    super.onCreate();
    int resp = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
    if (resp == ConnectionResult.SUCCESS) {
        locationclient = new LocationClient(this, this, this);
        locationclient.connect();

    } else {
        Toast.makeText(this, "Google Play Service Error " + resp,
                Toast.LENGTH_LONG).show();

    }
            intent = new Intent(BROADCAST_ACTION);
}


@Override
public void onStart(Intent intent, int startId) {

    if (locationclient != null && locationclient.isConnected()) {

        locationrequest = LocationRequest.create();
        locationrequest.setInterval(2000)
                .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY)
                .setSmallestDisplacement(0);

        locationclient.requestLocationUpdates(locationrequest, this);

    }

}
    @Override
public void onConnected(Bundle connectionHint) {
    // TODO Auto-generated method stub

    if (locationclient != null && locationclient.isConnected()) {

        locationrequest = LocationRequest.create();
        locationrequest.setInterval(1000)
                .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY)
                .setSmallestDisplacement(0);

        locationclient.requestLocationUpdates(locationrequest, this);

    }

}
@Override
public void onDestroy() {

    locationclient.removeLocationUpdates(this);
    locationclient.disconnect();

}
@Override
public void onLocationChanged(Location location) {
    ....
    intent.putExtra("Latitude", location.getLatitude());
    intent.putExtra("Longitude", location.getLongitude());
    sendBroadcast(intent, null);
    ...

}

我的主要活动是：

 public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    txtConnectionStatus = (TextView) findViewById(R.id.txtConnectionStatus);

    txtLocationRequest = (TextView) findViewById(R.id.txtLocationRequest);
    timer = (Chronometer) findViewById(R.id.timer);

    mAddress = (TextView) findViewById(R.id.address);
    mActivityIndicator = (ProgressBar) findViewById(R.id.address_progress);

    mIntentService = new Intent(this, LocationService.class);
    mLocation = new Location("");
    intent= new Intent(this, LocationService.class);
}
...
@Override
public void onResume() {
    super.onResume();       

    registerReceiver(broadcastReceiver, new IntentFilter(LocationService.BROADCAST_ACTION));
}

@Override
public void onPause() {
    super.onPause();
    unregisterReceiver(broadcastReceiver);      
}

private BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {

    @Override
    public void onReceive(Context context, Intent intent) {
        // TODO Auto-generated method stub

        Bundle extras = intent.getExtras();
        double latitude = extras.getDouble("Latitude");
        double longitude = extras.getDouble("Longitude");
txtLocationRequest.setText("Latitude: "+ extras.getDouble("Latitude")+"\n"+
        "Longitude: "+ extras.getDouble("Longitude")
        }
};

... }

Answer 1

我已经做过一些这样的事情，我可以提出两件事可能会有所帮助。一种方法（这就是我所做的）。是为你想要的东西声明静态变量，比如 currentLat 和 currentLong。然后在位置更改时更改这些值，然后您可以在主要活动中检查这些值。

或者你可以使用处理程序，如果你真的需要在每次更新位置时都知道

如果你不使用服务可能会更好，据我了解，服务仍然在主 ui 线程上处理，所以你并没有让你的应用程序更有效率。

好的，我现在感觉好多了

在你的服务中，声明

something extends Service{

public static double curlat
public static double curlong

...在

@Override
public void onLocationChanged(Location location) {
    ....
    if(location.hasLatitude()){curLat=location.getLatitude();}
    if(location.hasLongitude()){curLong=location.getLongitude();}

    ..

然后在你的 mainActivity 中

public void updateGui(){

 txtLocationRequest.setText("Latitude: "+ Service.curLat+"\n"+
    "Longitude: "+ Service.curLong);
    }

您可能会发现这种方法更容易？那么您需要做的就是调用更新 gui。我也不明白为什么你当前的代码不起作用？

Answer 2

尝试从您的活动中执行 runOnUiThread()。