android 定位的几种方式介绍

[地理位置] android 定位的几种方式介绍  

                     开发中对于地图及地理位置的定位是我们经常要用地，地图功能的使用使得我们应用功能更加完善，下面 www.androidkaifa.com 总结了一下网络中现有对于介绍android定位的几种方式，希望对大家有帮助：                                            

android 定位一般有四种方法，这四种方式分别是：GPS定位，WIFI定准，基站定位，AGPS定位，                                             

（1） Android GPS：需要GPS硬件支持，直接和卫星交互来获取当前经纬度，这种方式需要手机支持GPS模块（现在大部分的智能机应该都有了）。通过GPS方式准确度是最高的，但是它的缺点也非常明显：1，比较耗电；2，绝大部分用户默认不开启GPS模块；3，从GPS模块启动到获取第一次定位数据，可能需要比较长的时间；4，室内几乎无法使用。这其中，缺点2,3都是比较致命的。需要指出的是，GPS走的是卫星通信的通道，在没有网络连接的情况下也能用。要实用Adnroid平台的GPS设备，首先需要添加上权限，所以需要添加如下权限：                                              

uses-permission android:name= android.permission.ACCESS_FINE_LOCATION   /uses-permission                                            

具体实现代码如下：                                             首先判断GPS模块是否存在或者是开启：                                             private voidopenGPSSettings() {                                                     LocationManager alm = (LocationManager)this                                                            .getSystemService(Context.LOCATION_SERVICE);                                                     if (alm                                                            .isProviderEnabled(android.location.LocationManager.GPS_PROVIDER)) {                                                         Toast.makeText(this,  GPS模块正常 ,Toast.LENGTH_SHORT)                                                                 .show();                                                         return;                                                     }                                                     Toast.makeText(this,  请开启GPS！ ,Toast.LENGTH_SHORT).show();                                                     Intent intent = newIntent(Settings.ACTION_SECURITY_SETTINGS);                                                    startActivityForResult(intent,0); //此为设置完成后返回到获取界面                                                 }                                             如果开启正常，则会直接进入到显示页面，如果开启不正常，则会进行到GPS设置页面：                                             获取代码如下：                                             private voidgetLocation()                                                 {                                                     // 获取位置管理服务                                                     LocationManager locationManager;                                                     String serviceName = Context.LOCATION_SERVICE;                                                     locationManager = (LocationManager)this.getSystemService(serviceName);                                                     // 查找到服务信息                                                     Criteria criteria = new Criteria();                                                    criteria.setAccuracy(Criteria.ACCURACY_FINE); // 高精度                                                     criteria.setAltitudeRequired(false);                                                     criteria.setBearingRequired(false);                                                     criteria.setCostAllowed(true);                                                    criteria.setPowerRequirement(Criteria.POWER_LOW); // 低功耗                                                     String provider =locationManager.getBestProvider(criteria, true); // 获取GPS信息                                                     Location location =locationManager.getLastKnownLocation(provider); // 通过GPS获取位置                                                     updateToNewLocation(location);                                                     // 设置监听*器，自动更新的最小时间为间隔N秒(1秒为1*1000，这样写主要为了方便)或最小位移变化超过N米                                                     locationManager.requestLocationUpdates(provider,100 * 1000, 500,                                                             locationListener);    }                                             到这里就可以获取到地理位置信息了，但是还是要显示出来，那么就用下面的方法进行显示：                                             代码                                             private voidupdateToNewLocation(Location location) {                                                     TextView tv1;                                                     tv1 = (TextView)this.findViewById(R.id.tv1);                                                     if (location != null) {                                                         double  latitude = location.getLatitude();                                                         double longitude=location.getLongitude();                                                         tv1.setText( 维度： +  latitude+  \n经度  +longitude);                                                     } else {                                                         tv1.setText( 无法获取地理信息 );                                                     }                                                 }                                             

（2)Android 基站定位：Android 基站定位只要明白了基站/WIFI定位的原理，自己实现基站/WIFI定位其实不难。基站定位一般有几种，第一种是利用手机附近的三个基站进行三角定位，由于每个基站的位置是固定的，利用电磁波在这三个基站间中转所需要时间来算出手机所在的坐标；第二种则是利用获取最近的基站的信息，其中包括基站 id，location area code、mobile country code、mobile network code和信号强度，将这些数据发送到google的定位web服务里，就能拿到当前所在的位置信息，误差一般在几十米到几百米之内。其中信号强度这个数据很重要，这里笔者就不多做解释了，直接给出一个文章，这个文章写的非常好，http://www.cnblogs.com/rayee/archive/2012/02/02/2336101.html

 （3）Android Wifi定位：根据一个固定的WifiMAC地址，通过收集到的该Wifi热点的位置，然后访问网络上的定位服务以获得经纬度坐标。因为它和基站定位其实都需要使用网络，所以在Android也统称为Network方式。                                            

代码：                                            

public classWiFiInfoManager implements Serializable {                                                 private static final long serialVersionUID= -4582739827003032383L;                                                 private Context context;                                                 public WiFiInfoManager(Context context) {                                                     super();                                                     this.context = context;                                                 }                                                 public WifiInfo getWifiInfo() {                                                     WifiManager manager = (WifiManager)context                                                            .getSystemService(Context.WIFI_SERVICE);                                                     WifiInfo info = new WifiInfo();                                                     info.mac =manager.getConnectionInfo().getBSSID();                                                     Log.i( TAG ,  WIFI MACis:  + info.mac);                                                     return info;                                                 }                                                 public class WifiInfo {                                                     public String mac;                                                     public WifiInfo() {                                                         super();                                                     }                                                 }                                             }                                             上面是取到WIFI的mac地址的方法，下面是把地址发送给google服务器,代码如下                                             public staticLocation getWIFILocation(WifiInfo wifi) {                                                     if (wifi == null) {                                                         Log.i( TAG ,  wifiis null. );                                                         return null;                                                     }                                                     DefaultHttpClient client = newDefaultHttpClient();                                                     HttpPost post = new HttpPost( http://www.google.com/loc/json );                                                     JSONObject holder = new JSONObject();                                                     try {                                                         holder.put( version , 1.1.0 );                                                         holder.put( host , maps.google.com );                                                         JSONObject data;                                                         JSONArray array = new JSONArray();                                                         if (wifi.mac != null   wifi.mac.trim().length()   0) {                                                             data = new JSONObject();                                                            data.put( mac_address , wifi.mac);                                                            data.put( signal_strength , 8);                                                             data.put( age , 0);                                                             array.put(data);                                                         }                                                         holder.put( wifi_towers ,array);                                                         Log.i( TAG , request json:  + holder.toString());                                                         StringEntity se = newStringEntity(holder.toString());                                                         post.setEntity(se);                                                         HttpResponse resp =client.execute(post);                                                         int state =resp.getStatusLine().getStatusCode();                                                         if (state == HttpStatus.SC_OK) {                                                             HttpEntity entity =resp.getEntity();                                                             if (entity != null) {                                                                 BufferedReader br = newBufferedReader(                                                                         newInputStreamReader(entity.getContent()));                                                                 StringBuffer sb = newStringBuffer();                                                                 String resute =  ;                                                                 while ((resute =br.readLine()) != null) {                                                                     sb.append(resute);                                                                 }                                                                 br.close();                                                                 Log.i( TAG , response json:  + sb.toString());                                                                 data = newJSONObject(sb.toString());                                                                 data = (JSONObject)data.get( location );                                                                 Location loc = newLocation(                                                                        android.location.LocationManager.NETWORK_PROVIDER);                                                                 loc.setLatitude((Double)data.get( latitude ));                                                                 loc.setLongitude((Double)data.get( longitude ));                                                                loc.setAccuracy(Float.parseFloat(data.get( accuracy )                                                                         .toString()));                                                                 loc.setTime(System.currentTimeMillis());                                                                 return loc;                                                             } else {                                                                 return null;                                                             }                                                         } else {                                                             Log.v( TAG , state +  );                                                             return null;                                                         }                                                     } catch (Exception e) {                                                         Log.e( TAG ,e.getMessage());                                                         return null;                                                     }                                                 }

（3.1）而WIFI定位与基站定位的结合，笔者也在网上找到一个很好的文章，笔者对此就不做任何解释，直接给出网址：                                             http://www.cnblogs.com/coffeegg/archive/2011/10/01/2197129.html                                            

（4）AGPS定位：AGPS（AssistedGPS：辅助全球卫星定位系统）是结合GSM或GPRS与传统卫星定位，利用基地台代送辅助卫星信息，以缩减GPS芯片获取卫星信号的延迟时间，受遮盖的室内也能借基地台讯号弥补，减轻GPS芯片对卫星的依赖度。和纯GPS、基地台三角定位比较，AGPS能提供范围更广、更省电、速度更快的定位服务，理想误差范围在10公尺以内，日本和美国都已经成熟运用AGPS于LBS服务（Location Based Service，基于位置的服务）。AGPS技术是一种结合了网络基站信息和GPS信息对移动台进行定位的技术，可以在GSM/GPRS、WCDMA和CDMA2000网络中使进行用。该技术需要在手机内增加GPS接收机模块，并改造手机的天线，同时要在移动网络上加建位置服务器、差分GPS基准站等设备。AGPS解决方案的优势主要体现在其定位精度上，在室外等空旷地区，其精度在正常的GPS工作环境下，可以达到10米左右，堪称目前定位精度最高的一种定位技术。该技术的另一优点为：首次捕获GPS信号的时间一般仅需几秒，不像GPS的首次捕获时间可能要2～3分钟    

http://www.cnblogs.com/cuihongyu3503319/p/3863867.html