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

package com.example.gpsbasics;

import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;
import android.app.Activity;
import android.content.Context;


public class MainActivity extends Activity implements LocationListener {

    private LocationManager locationManager;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        /********** get Gps location service LocationManager object ***********/
        /********** 获取GPS服务管理对象 ************/
        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
        
        /*
          Parameters :
             First(provider)    :  the name of the provider with which to register 
                                :  注册的名字
             Second(minTime)    :  the minimum time interval for notifications, in milliseconds. This field is only used as a hint to conserve power, and actual time between location updates may be greater or lesser than this value. 
                                :  最小通知时间间隔，以毫秒为单位。此字段仅作为节省电力方式，并且位置更新之间的实际时间可以比该值更大或更小。  
             Third(minDistance) :  the minimum distance interval for notifications, in meters 
                                :  最小间隔通知，以毫秒为单位
             Fourth(listener)   :  a {#link LocationListener} whose onLocationChanged(Location) method will be called for each location update 
                                :  每个位置更新时谁的onLocationChanged （位置）方法将被调用
        */
        
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,
                3000,   // 3 sec
                10, this);
        
        /********* After registration onLocationChanged method called periodically after each 3 sec ***********/
    }
    
    /************* Called after each 3 sec **********/
    @Override
    public void onLocationChanged(Location location) {
           
        // location.getLatitude()： 纬度
        // location.getLongitude(): 维度
        String str = "Latitude: "+location.getLatitude()+" \nLongitude: "+location.getLongitude();
        Toast.makeText(getBaseContext(), str, Toast.LENGTH_LONG).show();
        Log.e("GPSBasics", "onLocationChanged.");
    }

    @Override
    public void onProviderDisabled(String provider) {
        
        /******** Called when User off Gps *********/
        
        Toast.makeText(getBaseContext(), "Gps turned off ", Toast.LENGTH_LONG).show();
    }

    @Override
    public void onProviderEnabled(String provider) {
        
        /******** Called when User on Gps  *********/
        
        Toast.makeText(getBaseContext(), "Gps turned on ", Toast.LENGTH_LONG).show();
    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {
        // TODO Auto-generated method stub
        
    }
}