Android客户端GPS定位

AndroidManifest.xml文件配置：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="cn.itcast.main"
      android:versionCode="1"
      android:versionName="1.0">
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".Main"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <uses-library android:name="com.google.android.maps" />
    </application>
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_FIND_LOCATION" />
</manifest>

Main.java文件：

package cn.itcast.main;
import java.util.List;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapController;
import com.google.android.maps.MapView;
import com.google.android.maps.Overlay;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Point;
import android.location.Address;
import android.location.Criteria;
import android.location.Geocoder;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.view.MotionEvent;
import android.widget.TextView;

public class Main extends MapActivity{
    private MapController mapController;
    private GeoPoint geoPoint;
    private String msg;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        //获得mapview
        MapView mapView=(MapView) this.findViewById(R.id.mapview);
        //地图的显示格式为交通图
        mapView.setTraffic(true);
        //设置可控
        mapView.setClickable(true);
        mapView.setEnabled(true);
        mapView.setBuiltInZoomControls(true);
        
        //得到gps设备的访问
        LocationManager locationManager=(LocationManager) getSystemService(Context.LOCATION_SERVICE);
        //设置gps定位配置
        Criteria criteria=new Criteria();
         //设置显示精度
        criteria.setAccuracy(Criteria.ACCURACY_COARSE);
        //是否获得海拔数据
        criteria.setAltitudeRequired(false);
        //是否获得方向数据
        criteria.setBearingRequired(false);
        //是否允许运营商计费
        criteria.setCostAllowed(true);
        //设置耗电程度
        criteria.setPowerRequirement(Criteria.POWER_LOW);
        
        //获得服务供应商
        String provider=locationManager.getBestProvider(criteria, true);
        //获取上一个定位点
        Location location=locationManager.getLastKnownLocation(provider);
        //获得gps定位坐标信息
        Double latitude=location.getLatitude()*1E6;
        Double longitude=location.getLongitude()*1E6;
        //获得卫星定位点
        geoPoint=new GeoPoint(latitude.intValue(),longitude.intValue());
        
        //获得地图控制器
        mapController=mapView.getController();
        //设置地图显示初始化精度
        mapController.setZoom(12);
        mapController.animateTo(geoPoint);
        //实例化自定义绘图层
        MyOverlay myOverlay=new MyOverlay();
        //为mapview添加绘图层
        mapView.getOverlays().add(myOverlay);
        //定义一个final，TextView，以备子类引用
       final TextView textView=(TextView) findViewById(R.id.textview);
       LocationListener locationListener=new LocationListener() {
        
        @Override
        public void onStatusChanged(String provider, int status, Bundle extras) {
            
            
        }
        
        @Override
        public void onProviderEnabled(String provider) {
            // TODO Auto-generated method stub
            
        }
        
        @Override
        public void onProviderDisabled(String provider) {
            // TODO Auto-generated method stub
            
        }
        
        @Override
        public void onLocationChanged(Location location) {
            Double latitude=location.getLatitude()*1E6;
            Double longitude=location.getLongitude()*1E6;
            try {
                //获得精度纬度字符串
                msg = "经度：" + location.getLongitude() + "\n";
                msg += "纬度：" + location.getLatitude() + "\n";
                //根据经纬度获得改点地址信息
                Geocoder gc=new Geocoder(Main.this);
                List<Address> addresses=gc.getFromLocation(latitude, longitude, 1);
                if (addresses.size()>0) {
                    //获得地址信息
                    msg+="AddressLine:"+addresses.get(0).getAddressLine(0)+"\n";
                    //获得国家名
                    msg += "CountryName：" + addresses.get(0).getCountryName()+"\n";
                    msg += "Locality：" + addresses.get(0).getLocality() + "\n";
                    msg += "FeatureName：" + addresses.get(0).getFeatureName();
                }
                textView.setText(msg);
            } catch (Exception e) {
                e.printStackTrace();
            }
            
        }
    };
        //注册位置监听器，1秒钟扫描1次
        locationManager.requestLocationUpdates(provider, 1000, 0, locationListener);
        
    }

    
    class MyOverlay extends Overlay{
        //保证触控事件不重复操作
        private int count=0;
        @Override
        public boolean draw(Canvas canvas, MapView mapView, boolean shadow,
                long when) {
            //定义画笔
            Paint paint=new Paint();
            paint.setColor(Color.RED);
            //定义屏幕点
            Point screenPoint=new Point();
            //gps点转屏幕点
            mapView.getProjection().toPixels(geoPoint, screenPoint);
            //获得gps标志点图片
            Bitmap bitmap=BitmapFactory.decodeResource(getResources(), R.drawable.flag);
            //绘制gps点图片
            canvas.drawBitmap(bitmap, screenPoint.x,screenPoint.y, paint);
            //绘制文字说明
            canvas.drawText("当前位置", screenPoint.x, screenPoint.y, paint);
            return super.draw(canvas, mapView, shadow, when);
        }

        @Override
        public boolean onTouchEvent(MotionEvent e, MapView mapView) {
            //定义一个屏幕点
            Point screenPoint=new Point();
            //把gps点变成屏幕点
            mapView.getProjection().toPixels(geoPoint, screenPoint);
            //获得触点坐标
            int currentX=(int) e.getX();
            int currentY=(int) e.getY();
            //在50，30范围内触碰，显示当前经纬度
            if ((currentX-screenPoint.x)>=0&&(currentX-screenPoint.x)<50
                    &&(currentY-screenPoint.y>=0)&&(currentY-screenPoint.y)<30) {
                if (count==0) {
                    new AlertDialog.Builder(Main.this).setMessage(msg)
                    .setPositiveButton("确定",new OnClickListener(){

                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            count=0;
                        }
                        
                    }).show();
                }
                count++;
            }
            return super.onTouchEvent(e, mapView);
        }
        
    }
    
    
    @Override
    protected boolean isRouteDisplayed() {
        // TODO Auto-generated method stub
        return false;
    }
}

注1：如果你的手机上没有gps定位系统，会有以下错误

08-10 13:04:55.610: ERROR/AndroidRuntime(492): java.lang.RuntimeException: Unable to start activity ComponentInfo{cn.itcast.main/cn.itcast.main.Main}: java.lang.IllegalArgumentException: provider==null

注2：记得去google官网

http://code.google.com/intl/zh-CN/android/maps-api-signup.html

申请自己机器的apikey

C:\Documents and Settings\Administrator\.android>keytool -list -keystore debug.kEystore

默认密码android

我机器的apikey，你用不好使

  <com.google.android.maps.MapView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
android:apiKey="0EITsWoXq7NC_mgKW6yIxIViNLhMGsIW4dbmlsg
   />

最终实现效果：随着android客户端得移动，在地图上提供精确的当前所在位置