无法使用通用代码获取GPS位置 [英] Unable to get GPS Location with Common Code

问题描述

我有获取位置的代码，我相信它可以正常工作，但根本不起作用:

I have code to get location, which I believe must be working but it doesn't at all:

清单:

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION" /> 
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />

Java :

    LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    locationManager.requestLocationUpdates(
            LocationManager.GPS_PROVIDER, 
            0, 
            0,
            new MyLocationListener()
    );

    Criteria criteria = new Criteria();
    criteria.setAccuracy(Criteria.ACCURACY_FINE);
    criteria.setAltitudeRequired(false);
    criteria.setBearingRequired(false);
    criteria.setCostAllowed(true);
    criteria.setPowerRequirement(Criteria.POWER_LOW);

    String provider = locationManager.getBestProvider(criteria, true);

    Location location = locationManager.getLastKnownLocation(provider);
    System.out.println("location: " + location);

location打印null，并且监听器根本不会被调用.任何人都可以建议出什么问题了吗?如果我打开Goog​​le地图，它仍然可以返回我的位置.

location prints null and the listener never get called at all. Anyone can advise what's wrong? If I open Google Maps, it can return my location anyway.

注意:我正在用自己的设备进行测试

Note: I am testing with my device

推荐答案

在实用程序包中或任何适合使用以下代码的地方创建类SingleShotLocationProvider.

Create Class SingleShotLocationProvider in your utility package or wherever you are fine with below code.

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.support.v4.app.ActivityCompat;
import android.widget.Toast;

public class SingleShotLocationProvider {

    public  interface LocationCallback {
         void onNewLocationAvailable(Location location);
    }

    // calls back to calling thread, note this is for low grain: if you want higher precision, swap the
    // contents of the else and if. Also be sure to check gps permission/settings are allowed.
    // call usually takes <10ms
    public static void requestSingleUpdate(final Context context, final LocationCallback callback) {
        final LocationManager locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);


        if (Utility.checkAndRequestPermissionsForGPS(context)) {
            if (ActivityCompat.checkSelfPermission(context, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(context, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                Toast.makeText(context, "First enable LOCATION ACCESS in settings.", Toast.LENGTH_LONG).show();
                return;
            }
            boolean isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);

            if (isGPSEnabled) {
                Criteria criteria = new Criteria();
                criteria.setAccuracy(Criteria.ACCURACY_FINE);
                locationManager.requestSingleUpdate(criteria, new LocationListener() {
                    @Override
                    public void onLocationChanged(Location location) {
                        callback.onNewLocationAvailable(location);
                    }

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

                    @Override
                    public void onProviderEnabled(String provider) {
                    }

                    @Override
                    public void onProviderDisabled(String provider) {
                    }
                }, null);
            } else {
                boolean isNetworkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
                if (isNetworkEnabled) {
                    Criteria criteria = new Criteria();
                    criteria.setAccuracy(Criteria.ACCURACY_COARSE);
                    locationManager.requestSingleUpdate(criteria, new LocationListener() {
                        @Override
                        public void onLocationChanged(Location location) {
                            callback.onNewLocationAvailable(location);
                        }

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

                        @Override
                        public void onProviderEnabled(String provider) {
                        }

                        @Override
                        public void onProviderDisabled(String provider) {
                        }
                    }, null);
                }
            }
        }

    }

}

现在您在活动"中将其导入为

Now in you Activity import it like

import com.yourdomain.utils.SingleShotLocationProvider;

现在您可以像this所示那样使用它来引用您的活动

Now you can use it like below this is reference to your activity

 SingleShotLocationProvider.requestSingleUpdate(this,
                    new SingleShotLocationProvider.LocationCallback() {
                        @Override
                        public void onNewLocationAvailable(Location location) {
                            if (location != null) {
                                double latitude = location.getLatitude();
                                double longitude = location.getLongitude();
                                }
                             } 
                    }
                });

您将首先尝试获得位置信息，只需确保GPS处于打开状态并设置为高精度即可.清单中，您已获得必要的许可，如下所示-

You will receive location in first attempt just make sure GPS is on and set to high accuracy.And in manifest you have given necessary permission as like below -

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION" /> 
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />

这篇关于无法使用通用代码获取GPS位置的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！