在Android應用程序中,可以使用LocationManager來獲取移動設備所在的地理位置信息。看如下實例:新建android應用程序TestLocation。
1、activity_main.xml佈局文件
- <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
- android:layout_width="fill_parent"
- android:layout_height="fill_parent"
- >
- <TextView
- android:id="@+id/positionView"
- android:layout_width="wrap_content"
- android:layout_height="wrap_content"
- />
- </LinearLayout>
2、MainActivity.java
- package com.example.testlocation;
- import java.util.List;
- import android.app.Activity;
- import android.content.Context;
- import android.location.Location;
- import android.location.LocationListener;
- import android.location.LocationManager;
- import android.os.Bundle;
- import android.view.Menu;
- import android.widget.TextView;
- import android.widget.Toast;
- public class MainActivity extends Activity {
- private TextView postionView;
- private LocationManager locationManager;
- private String locationProvider;
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.activity_main);
- //獲取顯示地理位置信息的TextView
- postionView = (TextView) findViewById(R.id.positionView);
- //獲取地理位置管理器
- locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
- //獲取所有可用的位置提供器
- List<String> providers = locationManager.getProviders(true);
- if(providers.contains(LocationManager.GPS_PROVIDER)){
- //如果是GPS
- locationProvider = LocationManager.GPS_PROVIDER;
- }else if(providers.contains(LocationManager.NETWORK_PROVIDER)){
- //如果是Network
- locationProvider = LocationManager.NETWORK_PROVIDER;
- }else{
- Toast.makeText(this, "沒有可用的位置提供器", Toast.LENGTH_SHORT).show();
- return ;
- }
- //獲取Location
- Location location = locationManager.getLastKnownLocation(locationProvider);
- if(location!=null){
- //不爲空,顯示地理位置經緯度
- showLocation(location);
- }
- //監視地理位置變化
- locationManager.requestLocationUpdates(locationProvider, 3000, 1, locationListener);
- }
- /**
- * 顯示地理位置經度和緯度信息
- * @param location
- */
- private void showLocation(Location location){
- String locationStr = "維度:" + location.getLatitude() +"\n"
- + "經度:" + location.getLongitude();
- postionView.setText(locationStr);
- }
- /**
- * LocationListern監聽器
- * 參數:地理位置提供器、監聽位置變化的時間間隔、位置變化的距離間隔、LocationListener監聽器
- */
- LocationListener locationListener = new LocationListener() {
- @Override
- public void onStatusChanged(String provider, int status, Bundle arg2) {
- }
- @Override
- public void onProviderEnabled(String provider) {
- }
- @Override
- public void onProviderDisabled(String provider) {
- }
- @Override
- public void onLocationChanged(Location location) {
- //如果位置發生變化,重新顯示
- showLocation(location);
- }
- };
- @Override
- protected void onDestroy() {
- super.onDestroy();
- if(locationManager!=null){
- //移除監聽器
- locationManager.removeUpdates(locationListener);
- }
- }
- @Override
- public boolean onCreateOptionsMenu(Menu menu) {
- // Inflate the menu; this adds items to the action bar if it is present.
- getMenuInflater().inflate(R.menu.main, menu);
- return true;
- }
- }
(1)獲取LocationManager實例,通過getSystemService方法,傳入Context.LOCATION_SERVICE參數。
(2)獲取可用的位置提供器,有GPS_PROVIDER、NETWORK_PROVIDER、PASSIVE_PROVIDER三種,前兩種比較常用。
(3)將(2)獲取到的位置提供器傳入LocationManager的方法getLastKnownLocation,即可獲取Location信息。
如果移動設備地理位置不斷髮生變化,則實時更新需要進行如下步驟:
(4)調用LocationManager的requestLocationUpdates方法,第一個參數是位置提供器,第二個參數是監聽位置變化的時間間隔(毫秒),第三個參數是監聽位置變化的距 離間隔(米),第四個參數是LocationListener監聽器
(5)當位置發生變化後,就會調用監聽器的onLocationChanged方法。
(6)爲了省電,節約資源,當程序關閉後,調用LocationManager的removeUpdates方法移除監聽器。
3、獲取權限
修改AndroidManifest.xml,添加如下代碼:
- <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
- <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
- <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
使用模擬器進行測試:點擊send
可以使用Geocoding API查找具體對應的位置。如下:
(1)修改MainActivity.java
- package com.example.testlocation;
- import java.util.List;
- import org.apache.http.HttpEntity;
- import org.apache.http.HttpResponse;
- import org.apache.http.client.HttpClient;
- import org.apache.http.client.methods.HttpGet;
- import org.apache.http.impl.client.DefaultHttpClient;
- import org.apache.http.util.EntityUtils;
- import org.json.JSONArray;
- import org.json.JSONObject;
- import android.app.Activity;
- import android.content.Context;
- import android.location.Location;
- import android.location.LocationListener;
- import android.location.LocationManager;
- import android.os.Bundle;
- import android.os.Handler;
- import android.os.Message;
- import android.view.Menu;
- import android.widget.TextView;
- import android.widget.Toast;
- public class MainActivity extends Activity {
- private TextView postionView;
- private LocationManager locationManager;
- private String locationProvider;
- public static final int SHOW_LOCATION = 0;
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.activity_main);
- //獲取顯示地理位置信息的TextView
- postionView = (TextView) findViewById(R.id.positionView);
- //獲取地理位置管理器
- locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
- //獲取所有可用的位置提供器
- List<String> providers = locationManager.getProviders(true);
- if(providers.contains(LocationManager.GPS_PROVIDER)){
- //如果是GPS
- locationProvider = LocationManager.GPS_PROVIDER;
- }else if(providers.contains(LocationManager.NETWORK_PROVIDER)){
- //如果是Network
- locationProvider = LocationManager.NETWORK_PROVIDER;
- }else{
- Toast.makeText(this, "沒有可用的位置提供器", Toast.LENGTH_SHORT).show();
- return ;
- }
- //獲取Location
- Location location = locationManager.getLastKnownLocation(locationProvider);
- if(location!=null){
- //不爲空,顯示地理位置經緯度
- showLocation(location);
- }else{
- Toast.makeText(this, "location爲空", Toast.LENGTH_SHORT).show();
- }
- //監視地理位置變化
- locationManager.requestLocationUpdates(locationProvider, 3000, 1, locationListener);
- }
- private Handler handler = new Handler(){
- public void handleMessage(Message msg){
- switch(msg.what){
- case SHOW_LOCATION:
- String position = (String) msg.obj;
- postionView.setText(position);
- break;
- default:
- break;
- }
- }
- };
- /**
- * 顯示地理位置經度和緯度信息
- * @param location
- */
- private void showLocation(final Location location){
- /*String locationStr = "維度:" + location.getLatitude() +"\n"
- + "經度:" + location.getLongitude();
- postionView.setText(locationStr);*/
- new Thread(new Runnable() {
- @Override
- public void run() {
- try{
- //組裝反向地理編碼的接口位置
- StringBuilder url = new StringBuilder();
- url.append("http://maps.googleapis.com/maps/api/geocode/json?latlng=");
- url.append(location.getLatitude()).append(",");
- url.append(location.getLongitude());
- url.append("&sensor=false");
- HttpClient client = new DefaultHttpClient();
- HttpGet httpGet = new HttpGet(url.toString());
- httpGet.addHeader("Accept-Language","zh-CN");
- HttpResponse response = client.execute(httpGet);
- if(response.getStatusLine().getStatusCode() == 200){
- HttpEntity entity = response.getEntity();
- String res = EntityUtils.toString(entity);
- //解析
- JSONObject jsonObject = new JSONObject(res);
- //獲取results節點下的位置信息
- JSONArray resultArray = jsonObject.getJSONArray("results");
- if(resultArray.length() > 0){
- JSONObject obj = resultArray.getJSONObject(0);
- //取出格式化後的位置數據
- String address = obj.getString("formatted_address");
- Message msg = new Message();
- msg.what = SHOW_LOCATION;
- msg.obj = address;
- handler.sendMessage(msg);
- }
- }
- }catch(Exception e){
- e.printStackTrace();
- }
- }
- }).start();
- }
- /**
- * LocationListern監聽器
- * 參數:地理位置提供器、監聽位置變化的時間間隔、位置變化的距離間隔、LocationListener監聽器
- */
- LocationListener locationListener = new LocationListener() {
- @Override
- public void onStatusChanged(String provider, int status, Bundle arg2) {
- }
- @Override
- public void onProviderEnabled(String provider) {
- }
- @Override
- public void onProviderDisabled(String provider) {
- }
- @Override
- public void onLocationChanged(Location location) {
- //如果位置發生變化,重新顯示
- showLocation(location);
- }
- };
- @Override
- protected void onDestroy() {
- super.onDestroy();
- if(locationManager!=null){
- //移除監聽器
- locationManager.removeUpdates(locationListener);
- }
- }
- @Override
- public boolean onCreateOptionsMenu(Menu menu) {
- // Inflate the menu; this adds items to the action bar if it is present.
- getMenuInflater().inflate(R.menu.main, menu);
- return true;
- }
- }
- <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
- <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
- <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
- <uses-permission android:name="android.permission.INTERNET"/>