如何实现 LocationListener？

Question

这是我获取经度和纬度的源代码，但是如何实现位置监听器中的语句，我是新手，我真的需要帮助，请提供帮助，谢谢。

public class Location extends AppCompatActivity{

    LocationManager locationManager=(LocationManager)getSystemService(LOCATION_SERVICE);
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_location);
        isLocationEnabled();

    }

    LocationListener locationListenerGPS=new LocationListener() {
        @Override
        public void onLocationChanged(android.location.Location location) {
            double latitude=location.getLatitude();
            double longitude=location.getLongitude();
            String msg="New Latitude: "+latitude + "New Longitude: "+longitude;
            Toast.makeText(getBaseContext(),msg,Toast.LENGTH_LONG).show();
        }

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

        }

        @Override
        public void onProviderEnabled(String provider) {

        }

        @Override
        public void onProviderDisabled(String provider) {

        }
    };


    protected void onResume(){
        super.onResume();
        isLocationEnabled();
    }

    private void isLocationEnabled() {

        if(!locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)){
            AlertDialog.Builder alertDialog=new AlertDialog.Builder(this);
            alertDialog.setTitle("Enable Location");
            alertDialog.setMessage("Your locations setting is not enabled. Please enabled it in settings menu.");
            alertDialog.setPositiveButton("Location Settings", new DialogInterface.OnClickListener(){
                public void onClick(DialogInterface dialog, int which){
                    Intent intent=new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                    startActivity(intent);
                }
            });
            alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener(){
                public void onClick(DialogInterface dialog, int which){
                    dialog.cancel();
                }
            });
            AlertDialog alert=alertDialog.create();
            alert.show();
        }
        else{
            AlertDialog.Builder alertDialog=new AlertDialog.Builder(this);
            alertDialog.setTitle("Confirm Location");
            alertDialog.setMessage("Your Location is enabled, please enjoy");
            alertDialog.setNegativeButton("Back to interface",new DialogInterface.OnClickListener(){
                public void onClick(DialogInterface dialog, int which){
                    dialog.cancel();
                }
            });
            AlertDialog alert=alertDialog.create();
            alert.show();
        }
    }

}

Answer 1

只需使用此代码：

public class Location extends AppCompatActivity {
    LocationManager locationManager;
    Context mContext;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_location);
        mContext=this;
        locationManager=(LocationManager) mContext.getSystemService(Context.LOCATION_SERVICE);
        locationManager.requestLocationUpdates( LocationManager.GPS_PROVIDER,
                2000,
                10, locationListenerGPS);
        isLocationEnabled();

    }

    LocationListener locationListenerGPS=new LocationListener() {
        @Override
        public void onLocationChanged(android.location.Location location) {
            double latitude=location.getLatitude();
            double longitude=location.getLongitude();
            String msg="New Latitude: "+latitude + "New Longitude: "+longitude;
            Toast.makeText(mContext,msg,Toast.LENGTH_LONG).show();
        }

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

        }

        @Override
        public void onProviderEnabled(String provider) {

        }

        @Override
        public void onProviderDisabled(String provider) {

        }
    };


    protected void onResume(){
        super.onResume();
        isLocationEnabled();
    }

    private void isLocationEnabled() {

        if(!locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)){
            AlertDialog.Builder alertDialog=new AlertDialog.Builder(mContext);
            alertDialog.setTitle("Enable Location");
            alertDialog.setMessage("Your locations setting is not enabled. Please enabled it in settings menu.");
            alertDialog.setPositiveButton("Location Settings", new DialogInterface.OnClickListener(){
                public void onClick(DialogInterface dialog, int which){
                    Intent intent=new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                    startActivity(intent);
                }
            });
            alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener(){
                public void onClick(DialogInterface dialog, int which){
                    dialog.cancel();
                }
            });
            AlertDialog alert=alertDialog.create();
            alert.show();
        }
        else{
            AlertDialog.Builder alertDialog=new AlertDialog.Builder(mContext);
            alertDialog.setTitle("Confirm Location");
            alertDialog.setMessage("Your Location is enabled, please enjoy");
            alertDialog.setNegativeButton("Back to interface",new DialogInterface.OnClickListener(){
                public void onClick(DialogInterface dialog, int which){
                    dialog.cancel();
                }
            });
            AlertDialog alert=alertDialog.create();
            alert.show();
        }
    }
}

requestLocationUpdates方法的参数如下：

provider:The name of the provider with which we would like to register.
minTime:Minimum time interval between location updates (in milliseconds).
minDistance:Minimum distance between location updates (in meters).
listener:A LocationListener whose onLocationChanged(Location) method will be called for each location update.

权限：

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

为低于 lollipop 的版本添加上述权限到清单文件，对于棉花糖及更高版本使用运行时权限。