android Google Map定位及创建画布标示坐标点

最近公司做了一个关于android手机打车的应用，主要功能都在地图上了，正好研究了一下，总结了些技术点，基本都是网上翻得，加上了自己的理解。废话不多说，上码！

GPS状态监听：

package com.map;

import java.util.Iterator;

import com.dlvct.sns.socket.LogicServer;
import com.dlvct.sns.socket.clientpackets.CM_PLAYER_UP_DOWN_REQUEST;
import com.dlvct.sns.socket.model.MapInfo;

import android.content.Context;
import android.location.GpsSatellite;
import android.location.GpsStatus;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.location.LocationProvider;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.widget.Toast;

/**
 * GPS
 * 
 * GPS相关设置及位置取得等
 * 
 * @author 
 */
public class GPS implements LocationListener{

	private Context context;
	private Handler mHandler;
    Location currentLocation ;
	LocationManager locationManager;
//    private GpsStatus gpsstatus;
	
	/**
	 * 机能说明：构造函数
	 * 
	 * @param IN
	 *            Context
	 * @param OUT
	 * 
	 */
	public GPS(Context appContext,Handler mHandler,LocationManager locationManager,Location currentLocation) {
		this.context = appContext;
		this.mHandler = mHandler;
		this.locationManager = locationManager;
		this.currentLocation = currentLocation;
	}
	
	
	
    //位置变化时触发   
	@Override
	public void onLocationChanged(Location location) {
//		Toast.makeText(context, "location.getProvider():"+location.getProvider(), Toast.LENGTH_SHORT).show();
		Log.v("GPSTEST", "Got New Location of provider:"+location.getProvider());
		
		if(currentLocation!=null){
			if(isBetterLocation(location, currentLocation)){  

                Log.v("GPSTEST", "It's a better location");  

                this.currentLocation= location; 

                showLocation(location);
                
			} else {  

                Log.v("GPSTEST", "Not very good!");  

            } 

		} else{  

            Log.v("GPSTEST", "It's first location");  

            this.currentLocation=location;  

            showLocation(location);

        } 
		
		MapInfo.getInstance().setLoc(location.getLongitude(), location.getLatitude());
		
		LogicServer.logicServerConn.sendPacket(new CM_PLAYER_UP_DOWN_REQUEST(), mHandler);

		//移除基于LocationManager.NETWORK_PROVIDER的监听器  

        if(LocationManager.NETWORK_PROVIDER.equals(location.getProvider())){  

            locationManager.removeUpdates(this);  

        }  
//
//        MapInfo.getInstance().setLoc(location.getLongitude(), location.getLatitude());
//
//        LogicServer.logicServerConn.sendPacket(new CM_PLAYER_UP_DOWN_REQUEST(), mHandler);
		
	}
	//gps禁用时触发 
	@Override
	public void onProviderDisabled(String provider) {
		Log.d("Location", "onProviderDisabled");
		//这里可以执行提醒用户开启GPS操作
        Toast.makeText(context, "请开启GPS！", Toast.LENGTH_SHORT).show();
	}
	//gps开启时触发
	@Override
	public void onProviderEnabled(String provider) {
		Log.d("Location", "onProviderEnabled");
		//这里可以提醒用户GPS已经正常开启
		
	}

	//gps状态变化时触发  
	@Override
	public void onStatusChanged(String provider, int status, Bundle extras) {
		Log.d("Location", "onStatusChanged");
		if(status==LocationProvider.AVAILABLE){     
			Log.e(null, "当前GPS状态：可见的");
        }else if(status==LocationProvider.OUT_OF_SERVICE){     
			Log.e(null, "当前GPS状态：服务区外");
        }else if(status==LocationProvider.TEMPORARILY_UNAVAILABLE){  
			Log.e(null, "当前GPS状态：暂停服务");       
        } 
		
	}
	
	private void showLocation(Location location){  

	    //纬度  

	    Log.v("GPSTEST","Latitude:"+location.getLatitude());  

	    //经度  

	    Log.v("GPSTEST","Longitude:"+location.getLongitude());  

	    //精确度  

	    Log.v("GPSTEST","Accuracy:"+location.getAccuracy());  

	    //Location还有其它属性，请自行探索  

	}


	
	public void removeListener(){
		locationManager.removeUpdates(this);
	}
	
	
	
    private static final int CHECK_INTERVAL = 1000 * 30;  
    /**
     * 判断获取的位置是否更好
     * @author Administrator
     */
    protected boolean isBetterLocation(Location location,  

            Location currentBestLocation) {  

        if (currentBestLocation == null) {  

            // A new location is always better than no location  

            return true;  

        }  

        // Check whether the new location fix is newer or older  

        long timeDelta = location.getTime() - currentBestLocation.getTime();  

        boolean isSignificantlyNewer = timeDelta > CHECK_INTERVAL;  

        boolean isSignificantlyOlder = timeDelta < -CHECK_INTERVAL;  

        boolean isNewer = timeDelta > 0;  

        // If it's been more than two minutes since the current location,  

        // use the new location  

        // because the user has likely moved  

        if (isSignificantlyNewer) {  

            return true;  

            // If the new location is more than two minutes older, it must  

            // be worse  

        } else if (isSignificantlyOlder) {  

            return false;  

        }  

        // Check whether the new location fix is more or less accurate  

        int accuracyDelta = (int) (location.getAccuracy() - currentBestLocation  

                .getAccuracy());  

        boolean isLessAccurate = accuracyDelta > 0;  

        boolean isMoreAccurate = accuracyDelta < 0;  

        boolean isSignificantlyLessAccurate = accuracyDelta > 200;  

        // Check if the old and new location are from the same provider  

        boolean isFromSameProvider = isSameProvider(location.getProvider(),  

                currentBestLocation.getProvider());  

        // Determine location quality using a combination of timeliness and  

        // accuracy  

        if (isMoreAccurate) {  

            return true;  

        } else if (isNewer && !isLessAccurate) {  

            return true;  

        } else if (isNewer && !isSignificantlyLessAccurate  

                && isFromSameProvider) {  

            return true;  

        }  

        return false;  

    }  

    /** Checks whether two providers are the same */  

    private boolean isSameProvider(String provider1, String provider2) {  

        if (provider1 == null) {  

            return provider2 == null;  

        }  

        return provider1.equals(provider2);  

    } 


//  private GpsStatus.Listener gpsListener = new GpsStatus.Listener(){
//
//		@Override
//		public void onGpsStatusChanged(int event) {
//			//获取当前状态             
//			gpsstatus=locationManager.getGpsStatus(null);
//			
//			switch(event){
//			//第一次定位时的事件                 
//			case GpsStatus.GPS_EVENT_FIRST_FIX:
//				Log.e("Location", "第一次定位时的事件"); 
//				break;
//				//开始定位的事件                 
//			case GpsStatus.GPS_EVENT_STARTED:
//				Log.e("Location", "开始定位的事件"); 
//				break;
//			//发送GPS卫星状态事件                  
//			case GpsStatus.GPS_EVENT_SATELLITE_STATUS:
//				Log.e("Location", "发送GPS卫星状态事件"); 
//				
//				//获取卫星颗数的默认最大值
//				int count1 = gpsstatus.getMaxSatellites();
//				Log.e(null, "卫星列表的最大卫星数："+count1);
//				//创建一个迭代器保存所有卫星 
////				Iterable<GpsSatellite> allSatellites = gpsstatus.getSatellites();  
////				Iterator<GpsSatellite> it = allSatellites.iterator(); 
//				
////				int count = 0;
////				while(it.hasNext() && count <= maxSatellites){
////					Log.e(null, "while count:"+count);
////					count++;
////				}
////				Toast.makeText(context, "Satellite Count:" + count, Toast.LENGTH_SHORT).show();
////				Log.e("Satellite Count:", "count:"+count); 
//				break;
//			//停止定位事件 
//			case GpsStatus.GPS_EVENT_STOPPED: 
//				Log.e("Location", "停止定位事件 "); 
//				break;
//			}
//		}
//  };
//  
    
    
	/**
	 * 机能说明：判断GPS是否开启
	 * 
	 * @param IN
	 * @param OUT 
	 * 
	 */
	public boolean openGPSSettings() {
		LocationManager alm = (LocationManager) context
				.getSystemService(Context.LOCATION_SERVICE);
		if (alm.isProviderEnabled(android.location.LocationManager.GPS_PROVIDER)) {
			return true;
		} else {
			return false;
		}
	}
}

activity继承MapActivity 并创建监听，调用GPS：

	//位置信息
	Location currentLocation ;
	//位置服务
	private LocationManager locationManager;
	//GPS监听
	private LocationListener gpsListener=null;  
	//network监听
    private LocationListener networkListner=null;  

	public void getLocation() {
		/* 获取位置管理服务 */
		
		String serviceName = Context.LOCATION_SERVICE;
		locationManager = (LocationManager) this.getSystemService(serviceName);
		registerLocationListener();
		
	}


    /**
     * 以下是开始监听:同时开启两个监听
     * @author Administrator
     */
    private void registerLocationListener(){  

        networkListner=new GPS(MapControllerActivity.this,mHandler,locationManager,currentLocation);  

        locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 3000, 0, networkListner);  

        gpsListener=new GPS(MapControllerActivity.this,mHandler,locationManager,currentLocation); 

        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 6000*10, 0, gpsListener);  

    }  
	

以上代码就是GPS定位了，包括network和GPS定位，network定位后将监听销毁，保留GPS监听。

下一步就是讲获得的经纬度以画布的形式画到地图上显示。

package com.map;

import java.util.*;

import android.app.AlertDialog;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.graphics.Canvas;
import android.graphics.drawable.Drawable;
import android.util.Log;
import android.view.GestureDetector;
import android.view.MotionEvent;

import com.dlvct.sns.R;
import com.google.android.maps.*;


/**
 * 位置表示
 * 
 * 地图上显示位置PIN等信息
 *
 * @author 
 */
public class PlaceOverlay extends ItemizedOverlay<OverlayItem> implements GestureDetector.OnGestureListener  {
	
	private List<OverlayItem> mOverlays = new ArrayList<OverlayItem>();
	private Context context;
	public static Boolean longDown=false;
	public static float lat;
	public static float lon;
	
	GeoPoint point;
	MapView mapView;
	/**
	 * 构造方法
	 * 机能说明：地图上描绘PIN
	 * 
	 * @param IN
	 *           Drawable
	 * @param OUT 
	 * 
	 */
	public PlaceOverlay(Drawable defaultMarker,Context context) {
		super(boundCenterBottom(defaultMarker));
		this.context = context;
	}
	
	/**
	 * 机能说明：追加PIN
	 * 
	 * @param IN
	 *           OverlayItem
	 * @param OUT 
	 * 
	 */
	public void addOverlay(OverlayItem overlay) {
		mOverlays.add(overlay);
		populate();
	}
	
	/**
	 * 机能说明：移除PIN
	 * 
	 * @param IN
	 * @param OUT 
	 * 
	 */
	public void removeAllOverlay() {
		mOverlays.clear();
		populate();
	}
	
	/**
	 * 机能说明：创建项目
	 * 
	 * @param IN
	 * @param OUT 
	 * 
	 */
	@Override
	protected OverlayItem createItem(int i) {
		return mOverlays.get(i);
	}

	/**
	 * 机能说明：取得PIN个数
	 * 
	 * @param IN
	 * @param OUT 
	 * 
	 */
	@Override
	public int size() {
		return mOverlays.size();
		
	}

	
	/**
	 * 机能说明：点击PIN
	 * 
	 * @param IN
	 * @param OUT 
	 * 
	 */
	@Override
	public boolean onTap(int index) {
		setFocus(mOverlays.get(index));
		Log.e(null, "点击图标编号："+index);
		return super.onTap(index);
	}
	
	
	/**
	 * 点击地图任意点获取经纬度
	 */
	@Override
	public boolean onTap(GeoPoint point, MapView mapView) {
		//p获取的经纬度数据是整型变量,需要转换为float类型
		lat=point.getLatitudeE6();
		lon=point.getLongitudeE6();
		if(longDown==true){
			this.point=point;
			this.mapView=mapView;
			List<Overlay> mapOverlays = mapView.getOverlays();
			Log.e(null, "mapOverlays的长度："+mapOverlays.size());
			if(mapOverlays.size()>1){
				mapOverlays.remove(1);
			}
			if(mapOverlays.size()==1){
				Log.e(null, "mapOverlays的长度2："+mapOverlays.size());
				Drawable drawable = context.getResources().getDrawable(R.drawable.pin_red);
				//创建画布，将图标画到画布上
				PlaceOverlay overlay = new PlaceOverlay(drawable,context);
				/* 创建标记 */
				OverlayItem overlayItem = new OverlayItem(point, "标记title","标记摘要");
				overlay.addOverlay(overlayItem); 
				mapOverlays.add(overlay);
				Log.e(null, "what?????!");
			}
			
		}
		//将当前的经纬度显示出来
		Log.e(null, "lat:"+lat);
		Log.e(null, "lon:"+lon);
//		return super.onTap(point, mapView);
		return false;
	}
	
	
	@Override
	public void draw(Canvas canvas, MapView mapView, boolean shadow) {
		// TODO Auto-generated method stub
		super.draw(canvas, mapView, shadow);
	}
	
	
	
	
   private void DeleteOnClick() {
        // 创建AlertDialog.Builder对象
        AlertDialog.Builder builder = new AlertDialog.Builder(
                context);
        // alert绑定图标
        builder.setIcon(R.drawable.icon);
        // 表头
        builder.setTitle(R.string.Common_GpsOpen);
        builder.setMessage("");
        // 同意按钮
        builder.setPositiveButton(R.string.Button_OK, new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int whichButton) {
            	List<Overlay> mapOverlays = mapView.getOverlays();
    			if(mapOverlays.size()>1){
    	        	mapOverlays.remove(1);
    	        }
    			Drawable drawable = context.getResources().getDrawable(R.drawable.pin_red);
    			//创建画布，将图标画到画布上
    	        PlaceOverlay overlay = new PlaceOverlay(drawable,context);
    	        /* 创建标记 */
    	        OverlayItem overlayItem = new OverlayItem(point, "标记title","标记摘要");
    	        overlay.addOverlay(overlayItem); 
    	        mapOverlays.add(overlay);
                // 关闭提示框
                dialog.dismiss();
            }
        });
        // 取消按钮
        builder.setNegativeButton(R.string.Button_cancel, new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int whichButton) {
                dialog.dismiss();
            }
        });
        builder.create().show();
    }

	@Override
	public boolean onDown(MotionEvent e) {
		// TODO Auto-generated method stub
		return true;
	}
	
	@Override
	public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
			float velocityY) {
		// TODO Auto-generated method stub
		return true;
	}
	
	@Override
	public void onLongPress(MotionEvent e) {
		// TODO Auto-generated method stub
		Log.e(null, "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa");
		
	}
	
	@Override
	public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX,
			float distanceY) {
		// TODO Auto-generated method stub
		return false;
	}
	
	@Override
	public void onShowPress(MotionEvent e) {
		// TODO Auto-generated method stub
		
	}
	
	@Override
	public boolean onSingleTapUp(MotionEvent e) {
		// TODO Auto-generated method stub
		return false;
	}
	
}