為什么我的代碼總是返回“無法獲取位置”？

Question

我試圖獲取用戶的位置，但是每當我運行此代碼時，它都會返回“無法獲取位置”。 我不確定為什么這行不通。 我正在Android Studio中的默認模擬器上運行它。 我做錯了什么？

import android.Manifest;
import android.app.Activity;
import android.content.Context;
import android.content.pm.PackageManager;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;

public class MainActivity extends Activity implements LocationListener {

LocationManager locationManager;
String provider;

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

    locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

    provider = locationManager.getBestProvider(new Criteria(), false);

    if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        // TODO: Consider calling
        //    public void requestPermissions(@NonNull String[] permissions, int requestCode)
        // here to request the missing permissions, and then overriding
        //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
        //                                          int[] grantResults)
        // to handle the case where the user grants the permission. See the documentation
        // for Activity#requestPermissions for more details.
        return;
    }
    Location location = locationManager.getLastKnownLocation(provider);

    if (location != null) {

        Log.i("Location Info", "Location achieved!");

    } else {

        Log.i("Location Info", "Unable to get location");

    }

}


@Override
protected void onResume() {
    super.onResume();

    if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        // TODO: Consider calling
        //    public void requestPermissions(@NonNull String[] permissions, int requestCode)
        // here to request the missing permissions, and then overriding
        //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
        //                                          int[] grantResults)
        // to handle the case where the user grants the permission. See the documentation
        // for Activity#requestPermissions for more details.
        return;
    }
    locationManager.requestLocationUpdates(provider, 400, 1, this);

}

@Override
protected void onPause() {
    super.onPause();

    if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        // TODO: Consider calling
        //    public void requestPermissions(@NonNull String[] permissions, int requestCode)
        // here to request the missing permissions, and then overriding
        //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
        //                                          int[] grantResults)
        // to handle the case where the user grants the permission. See the documentation
        // for Activity#requestPermissions for more details.
        return;
    }
    locationManager.removeUpdates(this);

}

@Override
public void onLocationChanged(Location location) {

    Double lat = location.getLatitude();
    Double lng = location.getLongitude();

    Log.i("Location info: Lat", lat.toString());
    Log.i("Location info: Lng", lng.toString());

}

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

}

@Override
public void onProviderEnabled(String provider) {

}

@Override
public void onProviderDisabled(String provider) {

}

public void getLocation(View view) {

    if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        // TODO: Consider calling
        //    public void requestPermissions(@NonNull String[] permissions, int requestCode)
        // here to request the missing permissions, and then overriding
        //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
        //                                          int[] grantResults)
        // to handle the case where the user grants the permission. See the documentation
        // for Activity#requestPermissions for more details.
        return;
    }
    Location location = locationManager.getLastKnownLocation(provider);

    onLocationChanged(location);


}

}

Answer 1

如果您使用的是Eclipse ，請嘗試執行此操作，轉到“ Window ->“ Open Perspective ->“ DDMS ->“ Emulator Control ，然后在“ Location Controls鍵入一個並單擊“ Send 。