我有阅读GPS纬度和经度的服务.我想从服务的locationlistener的onLocationChanged更新活动.
我怎样才能实现它？我一直在阅读Service Bound但看起来它只是用于调用服务中的方法的活动而不是服务调用Activity中的textView.绑定服务是不是可以实现呢？
解决方法
您应该使用服务中的
LocalBroadcastManager类将Intent发送回活动.
例如,包含单个TextView的Activity可以设置如下的BroadcastReceiver：
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final TextView textView = (TextView) findViewById(R.id.main_activity_text_view);
LocalBroadcastManager.getInstance(this).registerReceiver(
new BroadcastReceiver() {
@Override
public void onReceive(Context context,Intent intent) {
double latitude = intent.getDoubleExtra(LocationBroadcastService.EXTRA_LATITUDE,0);
double longitude = intent.getDoubleExtra(LocationBroadcastService.EXTRA_LONGITUDE,0);
textView.setText("Lat: " + latitude + ",Lng: " + longitude);
}
},new IntentFilter(LocationBroadcastService.ACTION_LOCATION_BROADCAST)
);
}
@Override
protected void onResume() {
super.onResume();
startService(new Intent(this,LocationBroadcastService.class));
}
@Override
protected void onPause() {
super.onPause();
stopService(new Intent(this,LocationBroadcastService.class));
}
}
基本服务可以广播所有位置更改,如下所示：
public class LocationBroadcastService extends Service {
public static final String
ACTION_LOCATION_BROADCAST = LocationBroadcastService.class.getName() + "LocationBroadcast",EXTRA_LATITUDE = "extra_latitude",EXTRA_LONGITUDE = "extra_longitude";
private static final int
MIN_TIME = 2000,MIN_DISTANCE = 1;
@Override
public void onCreate() {
super.onCreate();
LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
sendBroadcastMessage(locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER));
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER,MIN_TIME,MIN_DISTANCE,new LocationListener() {
@Override
public void onLocationChanged(Location location) {
sendBroadcastMessage(location);
}
@Override
public void onStatusChanged(String provider,int status,Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
}
);
}
private void sendBroadcastMessage(Location location) {
if (location != null) {
Intent intent = new Intent(ACTION_LOCATION_BROADCAST);
intent.putExtra(EXTRA_LATITUDE,location.getLatitude());
intent.putExtra(EXTRA_LONGITUDE,location.getLongitude());
LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
}
}
@Override
public IBinder onBind(Intent intent) {
return null;
}
}
