(android 地图实战开发)3 在地图上显示当前位置和自定义银行位置

前言:

 

下面讲述在MapView中显示当前位置,并同时已知的银行ATM机的位置

 

 

 

 

 

效果图:

 

 

 

 

 

1         实现效果说明:

 

实现显示当前位置和银行ATM机的位置,主要分以下两个步骤,

 

1)       根据位置服务找到当前的GPS坐标

 

 

2)       将当前坐标和ATM坐标,用图层的方式显示到地图上

 

 

 

2         根据位置服务找到当前的GPS坐标

 

l  设置应用的权限

 

在AndroidManifest.xml文件中设置ACCESS_FINE_LOCATION权限

 

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

 

 

 

• 获取 定位服务

 

String context=Context.LOCATION_SERVICE;

 

locationManager=(LocationManager)getSystemService(context);

 

 

 

•   根据定位服务获取位置

 

定位服务接口

 

[1]  LocationManager.getLastKnownLocation(provider)

 

注:获取最后一次定位坐标信息

 

 

 

[2] void android.location.LocationManager.requestLocationUpdates(String provider, long minTime, float minDistance, LocationListener listener)

 

注:对指定provider进行侦听,条件为 最小时间minTime ,最小距离minDistance

 

 

 

3         根据位置服务找到当前的GPS坐标

 

• 添加MyLocationOverlay层,显示当前位置.

 

List<Overlay> overlays=map_view.getOverlays(); // set location Overlay

 

       MyLocationOverlay mylocationOver=new MyLocationOverlay(this,map_view);

 

        overlays.add(mylocationOver);

 

        mylocationOver.enableCompass(); //显示指南针

 

    mylocationOver.enableMyLocation(); //允许当前位置

 

 

 

• 自定义层，显示ATM位置

 

集成ItemizedOverlay<OverlayItem>类

 

调用方式：

 

atm=new ATMDynamicItemizedOverlay(this.getResources().getDrawable(R.drawable.map_atm));

 

    overlays.add(atm);

 

    atm.addNewItem(new GeoPoint(lat.intValue()+1000,lng.intValue()), "marketText", "snippet");

 

 

 

4         源代码：

 

自定义 ATMDynamicItemizedOverlay 类

 

publicclass ATMDynamicItemizedOverlay extends ItemizedOverlay<OverlayItem>{

    private ArrayList<OverlayItem> items ;
    
    public ATMDynamicItemizedOverlay(Drawable defaultMarker)
    {
        super(boundCenterBottom(defaultMarker));
        items=new ArrayList<OverlayItem>();
        populate();
    }

    publicvoid addNewItem(GeoPoint location,String marketText,String snippet)
    {
        items.add(new OverlayItem(location,marketText,snippet));
        populate();
    }
    
    publicvoid removeItem(int index)
    {
        items.remove(index);
        populate();

    }
    
    @Override
    protected OverlayItem createItem(int index) {
        // TODO Auto-generated method stub
        
        return items.get(index);
    }

    @Override
    publicint size() {
        // TODO Auto-generated method stub
return items.size();
    }
    
}

 

 

 窗体文件

 

publicclass LocationMap extends MapActivity {
    LocationManager locationManager;
    MapView map_view;
    ATMDynamicItemizedOverlay atm;
     @Override   
      publicvoid onCreate(Bundle savedInstanceState) {  
          super.onCreate(savedInstanceState);  
         setContentView(R.layout.locationmap);
    
       //add bank button onclick event
         ImageView imgView_back=(ImageView)findViewById(R.id.map_imgView_back);
         imgView_back.setOnClickListener(new  ImageView.OnClickListener()
        {
            publicvoid onClick(View v){
                ViewUtility.NavigateActivate(LocationMap.this,Main.class );    
            
            }
        });
         
        //set MapControl 
        map_view =(MapView)findViewById(R.id.map_view);
        map_view.setStreetView(true);
        map_view.setTraffic(true);
        map_view.setBuiltInZoomControls(false);
        map_view.setSatellite(false);  
        
        List<Overlay> overlays=map_view.getOverlays(); // set location Overlay
        MyLocationOverlay mylocationOver=new MyLocationOverlay(this,map_view);
        overlays.add(mylocationOver);
        mylocationOver.enableCompass();
        mylocationOver.enableMyLocation();
        
        //set atm Overlay
        atm=new ATMDynamicItemizedOverlay(this.getResources().getDrawable(R.drawable.map_atm));
        overlays.add(atm);
        String context=Context.LOCATION_SERVICE;
        locationManager=(LocationManager)getSystemService(context);
        String provider=LocationManager.GPS_PROVIDER;
    
        
        //OverlayItem a=new OverlayItem(null, provider, provider;
        Location location =locationManager.getLastKnownLocation(provider);
        if(location!=null)
        {
            UpdateMapView(location);
        }
            
        locationManager.requestLocationUpdates(provider, 10000, 5, locationListener );
    
     }
     
     /* By new location ,update MapWiew's Label */
     privatevoid UpdateMapView(Location location)
     {
           MapController mapcontroller=map_view.getController();

            Double lat=location.getLatitude()*1E6;
            Double lng=location.getLongitude()*1E6;
            GeoPoint point=new GeoPoint(lat.intValue(),lng.intValue());
          
            mapcontroller.setCenter(point);
            mapcontroller.setZoom(20);
            mapcontroller.animateTo(point);
          
            atm.addNewItem(new GeoPoint(lat.intValue()+1000,lng.intValue()), "marketText", "snippet");
            Toast.makeText(this, "lat:"+ String.valueOf(lat.intValue())+"lng:"+String.valueOf(lng.intValue()), Toast.LENGTH_SHORT).show();
     }
     
     @Override
        publicboolean onKeyDown(int keyCode, KeyEvent event) {
            if(keyCode == KeyEvent.KEYCODE_BACK){
                ViewUtility.NavigateActivate(LocationMap.this, Main.class);
            }
                returnfalse;
        }
    @Override
    protectedboolean isRouteDisplayed() {
        // TODO Auto-generated method stub
returnfalse;
    }

     //create location listener
private LocationListener locationListener =new LocationListener(){
              //location is changed
            @Override
             publicvoid onLocationChanged(Location location) {
                UpdateMapView(location);
                 Log.d("Location", "onLocationChanged");
             }
    
             //location is Disable
       @Override
             publicvoid onProviderDisabled(String provider) {
               Log.d("Location", "onProviderDisabled");
             }
    
            //location is enabled
             @Override
           publicvoid onProviderEnabled(String provider) {
            Log.d("Location", "onProviderEnabled");
             }
     
             //location's status changes
             @Override
             publicvoid onStatusChanged(String provider, int status, Bundle extras) {
                Log.d("Location", "onStatusChanged");
             }
     };
 
}