Android编程获取地理位置的经度和纬度实例
本文实例讲述了Android编程获取地理位置的经度和纬度。分享给大家供大家参考,具体如下:
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
<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
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() +"\n" + "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:
<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
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() +"\n" + "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
<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"/>
希望本文所述对大家Android程序设计有所帮助。