Question

在查看了许多不同的指南/教程之后，当用户点击地图上的叠加层（标记）时，我发现自己迷失了如何实现简单的警告框/工具提示。

在我已经拥有的代码中实现它时，我看到的所有指南都令人困惑。标记来自外部JSON，我在其中获得纬度/经度来创建并将标记放置在地图上。到目前为止一切顺利，我有所有的标记，但是当用户点击它时，我似乎无法找到实现警报框/工具提示的最佳方法。

我的代码发布在下面...我知道它有很多东西，但任何帮助都表示赞赏。非常感谢你！

package ca.transcontinental.android.vanilla.demo;

import (...)   

public class GoogleMapActivity extends MapActivity implements LocationListener { 

    MapView mapView;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.location_map_layout);   
        LocationManager lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
        lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, this);

        this.mapView = (MapView) findViewById(R.id.mapview);
        this.mapView.setBuiltInZoomControls(true);
        this.mapView.getController().setZoom(10);               
    }

    private BaseApplication getBaseApplication() {
        return (BaseApplication)getApplication();
    }

    public void onLocationChanged(Location location) {
        if (location != null) {   

            String sLat = String.valueOf(location.getLatitude());
            String sLng = String.valueOf(location.getLongitude());

            try {
                getBaseApplication().debug("GPS: lat="+sLat + ", lng="+sLng);                       
                RestQueryEngine.getInstance().setup("http://example.com/JSONPublicationService.svc", "key", getBaseApplication().getOrgCode(), getBaseApplication().getBannerCode());
                StoreList list = StoreList.getStoreListByGeopos(sLat, sLng);                
                for(Store store: list){                 
                    System.out.println(store);  
                    MapOverlay overlay = new MapOverlay(Double.parseDouble(store.getLatitude()), Double.parseDouble(store.getLongitude()), "");
                    mapView.getOverlays().add(overlay);                 
                }
                mapView.invalidate();
            }
            catch (Throwable e) {
                e.printStackTrace();
                getBaseApplication().showExceptionMessage(e);
            }


            LocationManager lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
            lm.removeUpdates(this);

        }

    }


    public void onProviderDisabled(String provider) {
    }

    public void onProviderEnabled(String provider) {
    }

    public void onStatusChanged(String provider, int status, Bundle extras) {
    }

    @Override
    protected boolean isRouteDisplayed() {
        return false;
    }   

    class MapOverlay extends Overlay {
        private GeoPoint locpoint;
        private String label;

        public MapOverlay(GeoPoint geoPoint, String name) {
            this.locpoint = geoPoint;
            this.label = name;
        }
        public MapOverlay(double lat, double lon, String name) {
            this(new GeoPoint((int)(lat*1E6), (int)(lon*1E6)), name);           
        }           

        @Override
        public boolean draw(Canvas canvas, MapView mapView, boolean shadow, long when) {
            super.draw(canvas, mapView, shadow);
            Point screenPoint = new Point();            
            mapView.getProjection().toPixels(this.locpoint, screenPoint);
            Bitmap markerImage = BitmapFactory.decodeResource(getResources(), R.drawable.androidmarker);
            canvas.drawBitmap(markerImage, screenPoint.x - markerImage.getWidth() / 2, screenPoint.y - markerImage.getHeight() / 2, null);
            return true;
        }       

    }
}

Answer 1

我这样做的方法是使用OverlayItem而不是Overlay，并创建一个扩展ItemizedOverlay的类

class CustomItemizedOverlay extends ItemizedOverlay<OverlayItem> {

    private ArrayList<MapOverlay> mOverlays = new ArrayList<MapOverlay>();

    public CustomItemizedOverlay(Drawable defaultMarker) {
        super(boundCenterBottom(defaultMarker));
    }

    public void addItem(MapOverlay item) {
        mOverlays.add(item);
    }

    @Override
    protected MapOverlay createItem(int i) {
        return mOverlays.get(i);
    }

    @Override
    public int size() {
        return mOverlays.size();
    }

    @Override
    protected boolean onTap(int index) {
        // Handle tap for the given overlay item based on this index
        return super.onTap(index);
    }
}

这样做有好处，你将使用R.drawable.androidmarker作为默认标记，而不必在Overlay中实现draw方法，这是为你完成的。

在叠加点击上显示工具提示/提醒

1 个答案: