我正在使用经典的GPS跟踪器代码来检索我当前的位置，但我总是得到0作为lat和lon的回报，即使我尝试改变位置仍然总是0.请注意我已经使用了以下代码在预览应用程序中，它的工作原理。
manifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.apostolis.map1sttest">
<!-- Permition list bellow !-->
<uses-permission android:name="android.permission.INTERNET" /> <!-- internet -->
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> <!-- internet 3g/4g enabled-->
<uses-permission android:name="android.permission.GET_ACCOUNTS" /> <!-- Google accounts -->
<uses-permission android:name="android.permission.NETWORK" /> <!-- internet -->
<uses-permission android:name="android.permission.USE_CREDENTIALS" /> <!-- Google acconts -->
<uses-permission android:name="android.permission.READ_PHONE_STATE"/> <!-- phone info -->
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /> <!-- GPS -->
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/> <!-- GPS -->
<uses-feature android:name="android.hardware.location.gps" /> <!-- GPS (needed for android 5.0+) -->
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
GPStracker.java
package com.example.apostolis.map1sttest;
import android.app.AlertDialog;
import android.app.Service;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;
import android.provider.Settings;
import android.support.annotation.Nullable;
import android.widget.Toast;
/**
* Created by Apostolis on 10/27/2016.
*/
public class GPStracker extends Service implements LocationListener {
private final Context context;
boolean isGPSEnabled = false;
boolean isNetworkEnabled = false;
boolean canGetLocation = false;
Location location;
double latitude;
double longituzzde;
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10;
private static final long MIN_TIME_BW_UPDATES = 100;
protected LocationManager locationManager;
public GPStracker(Context context){
this.context = context;
getLocation();
}
public Location getLocation(){
try {
locationManager = (LocationManager)context.getSystemService(LOCATION_SERVICE);
isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
isNetworkEnabled = locationManager.isProviderEnabled(locationManager.NETWORK_PROVIDER);
if(!isGPSEnabled && !isGPSEnabled) {
} else {
this.canGetLocation = true;
if(isNetworkEnabled) {
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
if (locationManager != null) {
location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
if(isGPSEnabled) {
if(location == null) {
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
if(locationManager != null) {
location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if(location != null){
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return location;
}
public void stopUsingGPS(){
if(locationManager != null) {
locationManager.removeUpdates(GPStracker.this);
}
}
public double getLatitude() {
if(location != null) {
latitude = location.getLatitude();
}
return latitude;
}
public double getLongitude(){
if(location != null) {
longitude = location.getLongitude();
}
return longitude;
}
public boolean canGetLocation() {
return this.canGetLocation;
}
public void showSettingsAlert(){
AlertDialog.Builder alertDialog = new AlertDialog.Builder(context);
alertDialog.setTitle("GPS SETTINGS");
alertDialog.setMessage("GPS is not enabled.Go to Settings menu and enable it?");
alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
context.startActivity(intent);
}
}) ;
alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
alertDialog.show();
}
@Override
public void onLocationChanged(Location location) {
this.location = location;
getLatitude();
getLongitude();
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
@Nullable
@Override
public IBinder onBind(Intent intent) {
return null;
}
}
MainActivity.java
package com.example.apostolis.map1sttest;
import android.Manifest;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationListener;
import android.support.annotation.Nullable;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationServices;
public class MainActivity extends AppCompatActivity implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, LocationListener {
GPStracker gps;
private String lat,lon;
Button btnGetLocation;
private GoogleApiClient mGoogleApiClient;
private LocationRequest mLocationRequest;
private double mCurrentLatitude,mCurrentLongitude;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnGetLocation = (Button) findViewById(R.id.btgps);
//creating onClick listener for GPS.
btnGetLocation.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
gps = new GPStracker(MainActivity.this);
if (gps.canGetLocation()) {
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
lat = Double.toString(latitude);
lon = Double.toString(longitude);
Toast.makeText(MainActivity.this,
"Your Location is: Lat: " + lat.toString() + " Lon:" + lon.toString(), Toast.LENGTH_LONG).show();
} else {
gps.showSettingsAlert();
}
}
});
};
@Override
public void onLocationChanged(Location location) {
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
@Override
public void onConnected(@Nullable Bundle bundle) {
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.
return;
}
Location location = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
if (location == null) {
LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, (com.google.android.gms.location.LocationListener) this);
} else {
mCurrentLatitude = location.getLatitude();
mCurrentLongitude = location.getLongitude();
Toast.makeText(this, mCurrentLongitude + " * ********"+mCurrentLatitude, Toast.LENGTH_LONG).show();
}
}
@Override
public void onConnectionSuspended(int i) {
}
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
}
}
activity_main.xml中
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.apostolis.map1sttest.MainActivity">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hello World!" />
<Button
android:text="Button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:id="@+id/btgps" />
</RelativeLayout>
答案 0 :(得分：0)
implement GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, LocationListener
在您的活动中，并在覆盖方法中使用以下代码
@Override
public void onConnected(@Nullable Bundle bundle) {
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.
return;
}
Location location = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
if (location == null) {
LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, (com.google.android.gms.location.LocationListener) this);
} else {
Toast.makeText(this, location.getLatitude() + " * ********"+location.getLongitude(), Toast.LENGTH_LONG).show();
}
}
创建变量
private LocationRequest mLocationRequest;
protected GoogleApiClient mGoogleApiClient;
在onCreate方法
中添加此内容mLocationRequest = LocationRequest.create()
.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY)
.setInterval(10 * 1000) // 10 seconds, in milliseconds
.setFastestInterval(1 * 1000); // 1 second, in milliseconds
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.addApi(Places.GEO_DATA_API)
.build();
并在onResume
中添加if (!mGoogleApiClient.isConnected() && !mGoogleApiClient.isConnecting()) {
Log.e("Google API", "Connecting");
mGoogleApiClient.connect();
}