1.网络定位:根据ip地址定位,根据ip地址在实际地址数据库中查询实际地址。 缺点:动态ip导致地址不准确。 2.基站定位:3个基站就可以确定实际位置,定位范围是几百米到几公里不等。 3.GPS定位:美国卫星定位系统(北斗定位是中国的),至少3颗卫星就可以定位,GPS使用24颗卫星基本就可以覆盖全球90%范围,GPS不需要网络只要能够接受卫星信号就可以了,定位的精度比较准确几米到几十米不等。缺点是容易受云层和建筑干扰。 4.安卓采用A-GPS(辅助GPS定位系统),弥补GPS定位缺点,可以通过网络和GPS共同定位,如果GPS信号不强就用网络,网络信号不强就用GPS.范围是几米到几十米。
package com.itheima52.location; import java.util.List; import android.app.Activity; import android.location.Location; import android.location.LocationListener; import android.location.LocationManager; import android.os.Bundle; import android.widget.TextView; /* <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/> <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/> 粗糙位置信息, <uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION"/> 模拟器模拟的经纬度坐标, */ //获取经纬度 public class MainActivity extends Activity { private TextView tvLocation; private LocationManager lm; private MyLocationListener listener; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); tvLocation = (TextView) findViewById(R.id.tv_location); lm = (LocationManager) getSystemService(LOCATION_SERVICE); List<String> allProviders = lm.getAllProviders();// 获取所有位置提供者(网络(NETWORK_PROVIDER = "network"),基站(PASSIVE_PROVIDER = "passive"),GPS(GPS_PROVIDER = "gps")) System.out.println(allProviders); listener = new MyLocationListener(); // 参1表示位置提供者(通过GPS更新),参2表示最短更新位置时间0表示立即更新,参3表示最短更新位置距离0表示立即更新。 lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, listener); } class MyLocationListener implements LocationListener { // 位置发生变化回调 @Override public void onLocationChanged(Location location) { String j = "经度:" + location.getLongitude(); String w = "纬度:" + location.getLatitude(); String accuracy = "精确度:" + location.getAccuracy(); String altitude = "海拔:" + location.getAltitude(); tvLocation.setText(j + " " + w + " " + accuracy + " " + altitude); } // 位置提供者状态发生变化(GPS没有信号变成有信号) @Override public void onStatusChanged(String provider, int status, Bundle extras) { System.out.println("onStatusChanged"); } // 用户打开gps @Override public void onProviderEnabled(String provider) { System.out.println("onProviderEnabled"); } // 用户关闭gps @Override public void onProviderDisabled(String provider) { System.out.println("onProviderDisabled"); } } @Override protected void onDestroy() { super.onDestroy(); lm.removeUpdates(listener);// 手机定位其实是启动了一个服务,当activity销毁时,服务不会停止,所以要手动停止更新位置, 节省电量, } }
public class Demo { //火星坐标 public static void main(String[] args) { try { ModifyOffset instance = ModifyOffset.getInstance(ModifyOffset.class .getResourceAsStream("axisoffset.dat")); PointDouble s2c = instance.s2c(new PointDouble(116.29049474, 40.04302021));// 标准坐标转化为火星坐标 System.out.println(s2c); } catch (Exception e) { e.printStackTrace(); } } }
import java.io.InputStream; import java.io.ObjectInputStream; /** * 火星地球坐标转化.地图坐标修偏(火星坐标是人为加偏后的坐标) */ public class ModifyOffset { private static ModifyOffset modifyOffset; static double[] X = new double[660 * 450]; static double[] Y = new double[660 * 450]; private ModifyOffset(InputStream inputStream) throws Exception { init(inputStream); } public synchronized static ModifyOffset getInstance(InputStream is) throws Exception { if (modifyOffset == null) { modifyOffset = new ModifyOffset(is); } return modifyOffset; } public void init(InputStream inputStream) throws Exception { ObjectInputStream in = new ObjectInputStream(inputStream); try { int i = 0; while (in.available() > 0) { if ((i & 1) == 1) { Y[(i - 1) >> 1] = in.readInt() / 100000.0d; ; } else { X[i >> 1] = in.readInt() / 100000.0d; ; } i++; } } finally { if (in != null) in.close(); } } // standard -> china public PointDouble s2c(PointDouble pt) { int cnt = 10; double x = pt.x, y = pt.y; while (cnt-- > 0) { if (x < 71.9989d || x > 137.8998d || y < 9.9997d || y > 54.8996d) return pt; int ix = (int) (10.0d * (x - 72.0d)); int iy = (int) (10.0d * (y - 10.0d)); double dx = (x - 72.0d - 0.1d * ix) * 10.0d; double dy = (y - 10.0d - 0.1d * iy) * 10.0d; x = (x + pt.x + (1.0d - dx) * (1.0d - dy) * X[ix + 660 * iy] + dx * (1.0d - dy) * X[ix + 660 * iy + 1] + dx * dy * X[ix + 660 * iy + 661] + (1.0d - dx) * dy * X[ix + 660 * iy + 660] - x) / 2.0d; y = (y + pt.y + (1.0d - dx) * (1.0d - dy) * Y[ix + 660 * iy] + dx * (1.0d - dy) * Y[ix + 660 * iy + 1] + dx * dy * Y[ix + 660 * iy + 661] + (1.0d - dx) * dy * Y[ix + 660 * iy + 660] - y) / 2.0d; } return new PointDouble(x, y); } // china -> standard public PointDouble c2s(PointDouble pt) { int cnt = 10; double x = pt.x, y = pt.y; while (cnt-- > 0) { if (x < 71.9989d || x > 137.8998d || y < 9.9997d || y > 54.8996d) return pt; int ix = (int) (10.0d * (x - 72.0d)); int iy = (int) (10.0d * (y - 10.0d)); double dx = (x - 72.0d - 0.1d * ix) * 10.0d; double dy = (y - 10.0d - 0.1d * iy) * 10.0d; x = (x + pt.x - (1.0d - dx) * (1.0d - dy) * X[ix + 660 * iy] - dx * (1.0d - dy) * X[ix + 660 * iy + 1] - dx * dy * X[ix + 660 * iy + 661] - (1.0d - dx) * dy * X[ix + 660 * iy + 660] + x) / 2.0d; y = (y + pt.y - (1.0d - dx) * (1.0d - dy) * Y[ix + 660 * iy] - dx * (1.0d - dy) * Y[ix + 660 * iy + 1] - dx * dy * Y[ix + 660 * iy + 661] - (1.0d - dx) * dy * Y[ix + 660 * iy + 660] + y) / 2.0d; } return new PointDouble(x, y); } } class PointDouble { double x, y; PointDouble(double x, double y) { this.x = x; this.y = y; } public String toString() { return "x=" + x + ", y=" + y; } }
通过service启动坐标定位:
package com.itheima52.mobilesafe.service; import android.app.Service; import android.content.Context; import android.content.Intent; import android.content.SharedPreferences; import android.location.Criteria; import android.location.Location; import android.location.LocationListener; import android.location.LocationManager; import android.os.Bundle; import android.os.IBinder; /** * 获取经纬度坐标的service * 清单文件注册:<service android:name=".service.LocationService" ></service> * * //Context context; context.startService(new Intent(context, LocationService.class));// 开启定位服务,调用LocationService的onCreate方法。 SharedPreferences sp = context.getSharedPreferences("config",Context.MODE_PRIVATE); String location = sp.getString("location","getting location..."); System.out.println("location:" + location); abortBroadcast();// 中断短信的传递, 从而系统短信app就收不到内容了,不中断则系统短信还是能够接收到短信。 */ public class LocationService extends Service { private LocationManager lm; private MyLocationListener listener; private SharedPreferences mPref; @Override public IBinder onBind(Intent intent) { return null; } @Override public void onCreate() { super.onCreate(); mPref = getSharedPreferences("config", MODE_PRIVATE); lm = (LocationManager) getSystemService(LOCATION_SERVICE); // List<String> allProviders = lm.getAllProviders();// 获取所有位置提供者 // System.out.println(allProviders); Criteria criteria = new Criteria(); criteria.setCostAllowed(true);// 是否允许付费,比如使用3g网络定位,如果设为false则没有GPS只有流量因为要流量钱就不开启。 criteria.setAccuracy(Criteria.ACCURACY_FINE);//精确度为fine:一般的精确度。 String bestProvider = lm.getBestProvider(criteria, true);// 获取最佳位置提供者,true表示Provider可用就返回,false表示不管可不可用都返回。 listener = new MyLocationListener(); lm.requestLocationUpdates(bestProvider, 0, 0, listener);// 参1表示位置提供者,参2表示最短更新时间,参3表示最短更新距离 } // class MyLocationListener implements LocationListener { // 位置发生变化 @Override public void onLocationChanged(Location location) { System.out.println("get location!"); // 将获取的经纬度保存在sp中 mPref.edit() .putString( "location", "j:" + location.getLongitude() + "; w:" + location.getLatitude()).commit(); stopSelf();//停掉service } // 位置提供者状态发生变化 @Override public void onStatusChanged(String provider, int status, Bundle extras) { System.out.println("onStatusChanged"); } // 用户打开gps @Override public void onProviderEnabled(String provider) { System.out.println("onProviderEnabled"); } // 用户关闭gps @Override public void onProviderDisabled(String provider) { System.out.println("onProviderDisabled"); } } @Override public void onDestroy() { super.onDestroy(); lm.removeUpdates(listener);// 当activity销毁时,停止更新位置, 节省电量,否则服务会一直开启。 } }