我一直在编码一个使用GPS传感器来获取您的位置并将地图核心您周围的应用程序，我一直在使用funcion：
final LocationListener locationListenerFunc = new LocationListener()
但是它对我不起作用，我已经走了几个小时，但是我仍然看不到文本更改（当您进入onLocationChanged方法时，我会更改它，我正在按照示例做所有事情。
这是我的代码>有什么问题 ？
package greenroadproject.greenroadproject2;
import android.content.Context;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import android.text.format.Time;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.CameraPosition;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
public class MapsActivity extends FragmentActivity {
private GoogleMap mMap; // Might be null if Google Play services APK is not available.
private Button startTrackingButton;
private Button stopTrackingButton;
private TextView mainText;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.map_fragment_layout);
//GPS LOCATION MANAGER
final LocationManager manager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
final LocationListener locationListenerFunc = new LocationListener() {
@Override
public void onLocationChanged(Location location) {
/// HERE IS MY PROBLEM HE DOESN'T GO IN HERE
/// HERE IS MY PROBLEM HE DOESN'T GO IN HERE
mMap.animateCamera(CameraUpdateFactory.newLatLngZoom(
new LatLng(location.getLatitude(), location.getLongitude()), 13));
CameraPosition cameraPosition = new CameraPosition.Builder()
.target(new LatLng(location.getLatitude(), location.getLongitude())) // Sets the center of the map to location user
.zoom(17) // Sets the zoom
.bearing(90) // Sets the orientation of the camera to east
.tilt(30) // Sets the tilt of the camera to 30 degrees
.build(); // Creates a CameraPosition from the builder
mMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
Time today = new Time(Time.getCurrentTimezone());
today.setToNow();
mainText.setText("gotNew Location at: "+today.format("%k:%M:%S"));
///
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
};
//casting to button
startTrackingButton = (Button) findViewById(R.id.BTStartTracking);
stopTrackingButton = (Button) findViewById(R.id.BTStopTracking);
mainText = (TextView) findViewById(R.id.TVMainTextView);
//setting up map
setUpMapIfNeeded();
//start tracking button touch listener
stopTrackingButton.setOnClickListener(new Button.OnClickListener() {
public void onClick(View v) {
//Do stuff here
centerMapOnMyLocation(); //centers the map on user location
mainText.setText("user location enabled");
}
});
//stop tracking button touch listener
startTrackingButton.setOnClickListener(new Button.OnClickListener() {
public void onClick(View v) {
//Do stuff here
Time today = new Time(Time.getCurrentTimezone());
today.setToNow();
mainText.setText("first time is: "+today.format("%k:%M:%S"));
manager.requestLocationUpdates(LocationManager.GPS_PROVIDER,
3000, 0, locationListenerFunc);
}
});
}
@Override
protected void onResume() {
super.onResume();
setUpMapIfNeeded();
}
/**
* Sets up the map if it is possible to do so (i.e., the Google Play services APK is correctly
* installed) and the map has not already been instantiated.. This will ensure that we only ever
* call {@link #setUpMap()} once when {@link #mMap} is not null.
* <p/>
* If it isn't installed {@link SupportMapFragment} (and
* {@link com.google.android.gms.maps.MapView MapView}) will show a prompt for the user to
* install/update the Google Play services APK on their device.
* <p/>
* A user can return to this FragmentActivity after following the prompt and correctly
* installing/updating/enabling the Google Play services. Since the FragmentActivity may not
* have been completely destroyed during this process (it is likely that it would only be
* stopped or paused), {@link #onCreate(Bundle)} may not be called again so we should call this
* method in {@link #onResume()} to guarantee that it will be called.
*/
private void setUpMapIfNeeded() {
// Do a null check to confirm that we have not already instantiated the map.
if (mMap == null) {
// Try to obtain the map from the SupportMapFragment.
mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map))
.getMap();
// Check if we were successful in obtaining the map.
if (mMap != null) {
//setUpMap();
centerMapOnMyLocation(); //centers the map on user location
}
}
}
/**
* This is where we can add markers or lines, add listeners or move the camera. In this case, we
* just add a marker near Africa.
* <p/>
* This should only be called once and when we are sure that {@link #mMap} is not null.
*/
private void setUpMap() {
mMap.addMarker(new MarkerOptions().position(new LatLng(0, 0)).title("Marker"));
}
private void centerMapOnMyLocation() {
LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
Location location = locationManager.getLastKnownLocation(locationManager.getBestProvider(criteria, false));
//sets text >
double Lad = location.getLatitude();
double Long = location.getLongitude();
mainText.setText("lat: "+ String.valueOf(Lad)+", "+ "long: " +String.valueOf(Long));
if (location != null)
{
mMap.animateCamera(CameraUpdateFactory.newLatLngZoom(
new LatLng(location.getLatitude(), location.getLongitude()), 13));
CameraPosition cameraPosition = new CameraPosition.Builder()
.target(new LatLng(location.getLatitude(), location.getLongitude())) // Sets the center of the map to location user
.zoom(17) // Sets the zoom
.bearing(90) // Sets the orientation of the camera to east
.tilt(30) // Sets the tilt of the camera to 30 degrees
.build(); // Creates a CameraPosition from the builder
mMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
}
}
}
将 LocationManager.GPS_PROVIDER更改为 LocationManager.NETWORK_PROVIDER