Java ME引路蜂地图开发示例：放大、缩小

//--------------------------------- PACKAGE ------------------------------------
package com.pstreets.gisengine.demo.midp; 
 
//--------------------------------- IMPORTS ------------------------------------
import com.mapdigit.gis.geometry.GeoLatLng;
import com.mapdigit.gis.raster.MapType;
import com.pstreets.gisengine.demo.MapDemoMIDP;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable; 
 
//[------------------------------ MAIN CLASS ----------------------------------]
/**
 *  map zoom demo for Guidebee Map API on MIDP platform.
 */
public class MapZoomMIDP extends MapDemoMIDP implements CommandListener{ 
 
    private Command mapZoomInCommand=new Command("Zoom In",Command.OK,1);
    private Command mapZoomOutCommand=new Command("Zoom Out",Command.CANCEL,1); 
 
    public void startApp() {
        init();
        canvas.addCommand(mapZoomInCommand);
        canvas.addCommand(mapZoomOutCommand);
        canvas.setCommandListener(this);
        GeoLatLng center = new GeoLatLng(32.0616667, 118.7777778);
        map.setCenter(center, 13, MapType.MICROSOFTCHINA);
        Display.getDisplay(this).setCurrent(canvas);
    } 
 
     public void commandAction(Command c, Displayable d) {
        if(c==mapZoomInCommand){
            map.zoomIn(); 
 
        }else if(c==mapZoomOutCommand){
            map.zoomOut();
        }
    }
}