osm中的自定义覆盖标记

Question

我正在尝试使用自定义覆盖类为OSMdroid贴图制作自定义标记。我觉得我得到它，但它使我对平局构造器

这里一个的StackOverflowError是最主要的活动

package com.example.osmap1;import java.util.List; 

import org.osmdroid.util.GeoPoint; 
import org.osmdroid.views.MapController; 
import org.osmdroid.views.MapView; 
import org.osmdroid.views.overlay.Overlay; 

import com.example.osmap1.herramientas.MiOverlay; 

import android.os.Bundle; 
import android.app.Activity; 
import android.view.Menu; 

public class MainActivity extends Activity { 
MapView map; 
MapController mc; 
GeoPoint gp; 
List<Overlay> mOverlays; 

private static MainActivity mainActivity=null; 
public static MainActivity getInstance(){ 
    if(mainActivity == null){ 
     mainActivity=new MainActivity(); 

    } 
    return mainActivity; 
} 

@Override 
public void onCreate(Bundle savedInstanceState) { 

    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    mainActivity=this; 
    map=(MapView)findViewById(R.id.mapView); 

    mc=map.getController(); 
    map.setBuiltInZoomControls(true); 
    map.setMultiTouchControls(true); 

    addPointToMapOverlay("43.528023","-5.672949"); 

} 

private void addPointToMap (String latitud, String longitud){ 

    String coordenadas[]={latitud,longitud}; 
    double lat=Double.parseDouble(coordenadas[0]); 
    double lng=Double.parseDouble(coordenadas[1]); 
    GeoPoint gp=new GeoPoint((int)lat*1E6,(int)lng*1E6); 
    mc.animateTo(gp); 
    mc.setZoom(4); 
    /*map.invalidate(); no funciona en osm*/ 
} 

private void addPointToMapOverlay (String latitud, String longitud){ 


    String coordenadas[]={latitud,longitud}; 
    double lat=Double.parseDouble(coordenadas[0]); 
    double lng=Double.parseDouble(coordenadas[1]); 
    GeoPoint gp=new GeoPoint((int)lat*1E6,(int)lng*1E6); 

    mOverlays=map.getOverlays(); 
    MiOverlay marker= new MiOverlay(gp); 
    mOverlays.add(marker); 
    mc.animateTo(gp); 
    mc.setZoom(4); 
    map.invalidate(); 
} 



@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    getMenuInflater().inflate(R.menu.activity_main, menu); 
    return true; 
} 
} 

的代码，这是我的自定义类代码

public class MiOverlay extends Overlay{ 

private GeoPoint punto; 


public MiOverlay(GeoPoint point) { 

    super(MainActivity.getInstance().getBaseContext()); 
    this.punto=point; 
    // TODO Auto-generated constructor stub 
} 

@Override 
public void draw(Canvas canvas, MapView mapview, boolean shadow) { 

    // TODO Auto-generated method stub 
    this.draw(canvas, mapview, shadow); 

    //se traduce el punto geo localizado a un punto en la pantalla 
    Point scrnPoint = new Point(); 
    mapview.getProjection().toPixels(this.punto, scrnPoint); 

    //se construye un bitmap a partir de la imagen 
    Bitmap marker = BitmapFactory.decodeResource(MainActivity.getInstance().getResources(),com.example.osmap1.R.drawable.seas); 

    //se dibuja la imagen del marker 
    canvas.drawBitmap(marker, scrnPoint.x - marker.getWidth()/2, scrnPoint.y - marker.getHeight()/2, null); 


} 

public boolean onTouchEvent(MotionEvent event, MapView mapView) 
{ 
    //---when user lifts his finger--- 
    if (event.getAction() == 1) {     
     GeoPoint p = (GeoPoint) mapView.getProjection().fromPixels(
      (int) event.getX(), 
      (int) event.getY()); 
      Toast.makeText(MainActivity.getInstance().getBaseContext(), 
       p.getLatitudeE6()/1E6 + "," + 
       p.getLongitudeE6() /1E6 , 
       Toast.LENGTH_SHORT).show(); 
    }        
    return false; 
}   

} 

我觉得问题是mapview.getProjection（）。toMapPixels（this.punto，scrnPoint），但我不确定...任何消化都很顺利

Answer 1

这是一个无限循环 - 我承认我不太在意t和你想要做什么，但绘制函数递归调用自己：

@Override 
public void draw(Canvas canvas, MapView mapview, boolean shadow) { 

    this.draw(canvas, mapview, shadow); // This is the same method! 
} 

的结果，说明控制的流程，是这样的：

draw() 
-> draw() 
    -> draw() 
    ... 
    StackOverflowException 

也许你的意思super.draw(canvas, mapview, shadow)？