在Android应用程序中,可以使用LocationManager来获取移动设备所在的地理位置信息。看如下实例:新建android应用程序TestLocation。
1、activity_main.xml布局文件
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<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>
用于显示获取到的位置信息。
2、MainActivity.java
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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);
//获取显示地理位置信息的TextView
postionView = (TextView) findViewById(R.id.positionView);
//获取地理位置管理器
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
//获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, “没有可用的位置提供器”, Toast.LENGTH_SHORT).show();
return ;
}
//获取Location
Location location = locationManager.getLastKnownLocation(locationProvider);
if(location!=null){
//不为空,显示地理位置经纬度
showLocation(location);
}
//监视地理位置变化
locationManager.requestLocationUpdates(locationProvider, 3000, 1, locationListener);
}
/**
* 显示地理位置经度和纬度信息
* @param location
*/
private void showLocation(Location location){
String locationStr = “维度:” + location.getLatitude() +”
”
+ “经度:” + location.getLongitude();
postionView.setText(locationStr);
}
/**
* LocationListern监听器
* 参数:地理位置提供器、监听位置变化的时间间隔、位置变化的距离间隔、LocationListener监听器
*/
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) {
//如果位置发生变化,重新显示
showLocation(location);
}
};
@Override
protected void onDestroy() {
super.onDestroy();
if(locationManager!=null){
//移除监听器
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;
}
}
从上面可以看出,获取地理位置信息主要分如下步骤:
(1)获取LocationManager实例,通过getSystemService方法,传入Context.LOCATION_SERVICE参数。
(2)获取可用的位置提供器,有GPS_PROVIDER、NETWORK_PROVIDER、PASSIVE_PROVIDER三种,前两种比较常用。
(3)将(2)获取到的位置提供器传入LocationManager的方法getLastKnownLocation,即可获取Location信息。
如果移动设备地理位置不断发生变化,则实时更新需要进行如下步骤:
(4)调用LocationManager的requestLocationUpdates方法,第一个参数是位置提供器,第二个参数是监听位置变化的时间间隔(毫秒),第三个参数是监听位置变化的距 离间隔(米),第四个参数是LocationListener监听器
(5)当位置发生变化后,就会调用监听器的onLocationChanged方法。
(6)为了省电,节约资源,当程序关闭后,调用LocationManager的removeUpdates方法移除监听器。
3、获取权限
修改AndroidManifest.xml,添加如下代码:
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<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”/>
4、效果
使用模拟器进行测试:点击send
可以使用Geocoding API查找具体对应的位置。如下:
(1)修改MainActivity.java
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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);
//获取显示地理位置信息的TextView
postionView = (TextView) findViewById(R.id.positionView);
//获取地理位置管理器
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
//获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, “没有可用的位置提供器”, Toast.LENGTH_SHORT).show();
return ;
}
//获取Location
Location location = locationManager.getLastKnownLocation(locationProvider);
if(location!=null){
//不为空,显示地理位置经纬度
showLocation(location);
}else{
Toast.makeText(this, “location为空”, Toast.LENGTH_SHORT).show();
}
//监视地理位置变化
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;
}
}
};
/**
* 显示地理位置经度和纬度信息
* @param location
*/
private void showLocation(final Location location){
/*String locationStr = “维度:” + location.getLatitude() +”
”
+ “经度:” + location.getLongitude();
postionView.setText(locationStr);*/
new Thread(new Runnable() {
@Override
public void run() {
try{
//组装反向地理编码的接口位置
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);
//获取results节点下的位置信息
JSONArray resultArray = jsonObject.getJSONArray(“results”);
if(resultArray.length() > 0){
JSONObject obj = resultArray.getJSONObject(0);
//取出格式化后的位置数据
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监听器
* 参数:地理位置提供器、监听位置变化的时间间隔、位置变化的距离间隔、LocationListener监听器
*/
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) {
//如果位置发生变化,重新显示
showLocation(location);
}
};
@Override
protected void onDestroy() {
super.onDestroy();
if(locationManager!=null){
//移除监听器
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;
}
}
(2)修改AndroidManifest.xml
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<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”/>