每当我使用LocationManager和LocationListener时， 在使用AndroidEmulator时，我得到了位置， 设置纬度和经度时使用额外的工具
我签出了其他问题答案，但是我是Android开发的新手，所以我真的不明白答案。因此，我提出了一个新问题，我希望对代码进行审查。谢谢。
但是当我在物理设备上运行时，我的代码在启动时并没有提供我当前的位置。我如何获得当前位置？我也尝试过getLastKnownLocation，但即使这样也不起作用。
package com.londonappbrewery.climapm;
import android.Manifest;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import com.loopj.android.http.AsyncHttpClient;
import com.loopj.android.http.JsonHttpResponseHandler;
import com.loopj.android.http.RequestParams;
import org.json.JSONObject;
import cz.msebera.android.httpclient.Header;
public class WeatherController extends AppCompatActivity {
// Constants:
final String WEATHER_URL = "http://api.openweathermap.org/data/2.5/weather";
// App ID to use OpenWeather data
final String APP_ID = "5563c6a4ddd7d7181b257988cc2b1ad1";
// Time between location updates (5000 milliseconds or 5 seconds)
final long MIN_TIME = 5000;
// Distance between location updates (1000m or 1km)
final float MIN_DISTANCE = 1000;
//Request Code
final int REQUEST_CODE = 123;
// TODO: Set LOCATION_PROVIDER here:
String LOCATION_PROVIDER = LocationManager.GPS_PROVIDER;
// Member Variables:
TextView mCityLabel;
ImageView mWeatherImage;
TextView mTemperatureLabel;
// TODO: Declare a LocationManager and a LocationListener here:
LocationManager mLocationManager;
LocationListener mLocationListener;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.weather_controller_layout);
// Linking the elements in the layout to Java code
mCityLabel = (TextView) findViewById(R.id.locationTV);
mWeatherImage = (ImageView) findViewById(R.id.weatherSymbolIV);
mTemperatureLabel = (TextView) findViewById(R.id.tempTV);
ImageButton changeCityButton = (ImageButton) findViewById(R.id.changeCityButton);
// TODO: Add an OnClickListener to the changeCityButton here:
changeCityButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(WeatherController.this, ChangeCityController.class);
startActivity(intent);
}
});
}
// TODO: Add onResume() here:
@Override
protected void onResume() {
super.onResume();
Log.d("Clima", "onResume() called");
Intent intent = getIntent();
String cityName = intent.getStringExtra("cityName");
if (cityName != null) {
//Log.d("Clima", cityName);
getWeatherForNewCity(cityName);
} else {
Log.d("Clima", "Getting weather for current location");
getWeatherForCurrentLocation();
}
}
// TODO: Add getWeatherForNewCity(String city) here:
private void getWeatherForNewCity(String city) {
RequestParams params = new RequestParams();
params.put("q", city);
params.put("appid", APP_ID);
letsDoSomeNetworking(params);
}
// TODO: Add getWeatherForCurrentLocation() here:
private void getWeatherForCurrentLocation() {
mLocationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
mLocationListener = new LocationListener() {
@Override
public void onLocationChanged(Location location) {
//Log.d("Clima", "");
String latitude = String.valueOf(location.getLatitude());
String longitude = String.valueOf(location.getLongitude());
Log.d("Clima", "onLocationChanged() callback received");
Log.d("Clima", "Latitude is " + latitude);
Log.d("Clima", "Longitude is " + longitude);
RequestParams params = new RequestParams();
params.put("lat", latitude);
params.put("lon", longitude);
params.put("appid", APP_ID);
letsDoSomeNetworking(params);
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
Log.d("Clima", "onProviderDisabled() callback received");
}
};
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// 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 ActivityCompat#requestPermissions for more details.
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, REQUEST_CODE);
return;
}
mLocationManager.requestLocationUpdates(LOCATION_PROVIDER, MIN_TIME, MIN_DISTANCE, mLocationListener);
Location location = mLocationManager.getLastKnownLocation(LOCATION_PROVIDER);
if(location != null) {
RequestParams params = new RequestParams();
params.put("lat", location.getLatitude());
params.put("lon", location.getLongitude());
params.put("appid", APP_ID);
letsDoSomeNetworking(params);
}
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (requestCode == REQUEST_CODE) {
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Log.d("Clima", "onRequestPermissionResult(): Permission Granted!");
//mLocationManager.requestLocationUpdates(LOCATION_PROVIDER, MIN_TIME, MIN_DISTANCE, mLocationListener);
getWeatherForCurrentLocation();
}
}
}
// TODO: Add letsDoSomeNetworking(RequestParams params) here:
private void letsDoSomeNetworking(RequestParams params) {
AsyncHttpClient client = new AsyncHttpClient();
client.get(WEATHER_URL, params, new JsonHttpResponseHandler() {
@Override
public void onSuccess(int statusCode, Header[] header, JSONObject response) {
Log.d("Clima", "Success! JSON : " + response.toString());
WeatherDataModel weatherData = WeatherDataModel.fromJSON(response);
// Log.d("Clima", weatherData.getTemperature()); << WORKING
updateUI(weatherData);
}
@Override
public void onFailure(int statusCode, Header[] header, Throwable e, JSONObject response) {
Log.e("Clima", e.toString());
Log.d("Clima", String.valueOf(statusCode));
Toast.makeText(WeatherController.this, "Request Failed!", Toast.LENGTH_SHORT).show();
}
});
}
// TODO: Add updateUI() here:
private void updateUI(WeatherDataModel weatherData){
mTemperatureLabel.setText(weatherData.getTemperature());
mCityLabel.setText(weatherData.getCity());
int resourceID = getResources().getIdentifier(weatherData.getIconName(), "drawable", getPackageName());
mWeatherImage.setImageResource(resourceID);
}
// TODO: Add onPause() here:
}
应用启动后，我应该怎么做才能获得位置？
P.S。权限到位，所以这不是权限问题。
答案 0 :(得分：-5)
for="my_checkbox"在清单文件中添加以下权限：-
LocationManager locationManager =
(LocationManager)getSystemService(Context.LOCATION_SERVICE);
boolean networkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
Location location;
if(networkEnabled){
longitude=location.getLongitude();
latitude=location.getLatitude();
}
}