強制關閉mapController？

我有一個奇怪的問題。我想在地圖上顯示某個位置。問題是，有時一切正常，但有時我得到的力量關閉，並在DDMS我得到： 06 - 03：24：14.171：錯誤/ AndroidRuntime（2228）：在com.google.android.maps.MapController.setCenter （MapController.java:345）看來問題出現在：mapView.getController（）。setCenter（pt）。我可以理解，爲什麼有時一切都很好，有時並不好。強制關閉mapController？

這裏是我的代碼：

package com.ShoppingList.Shops; 


import java.io.IOException; 
import java.util.List; 
import java.util.Locale; 

import com.ShoppingList.R; 
import com.google.android.maps.GeoPoint; 
import com.google.android.maps.MapActivity; 
import com.google.android.maps.MapController; 
import com.google.android.maps.MapView; 

import java.util.ArrayList; 
import android.graphics.Canvas; 
import android.graphics.drawable.Drawable; 
import android.location.Address; 
import android.location.Geocoder; 
import android.os.Bundle; 
import com.google.android.maps.ItemizedOverlay; 
import com.google.android.maps.OverlayItem; 

public class ShowMap extends MapActivity { 
    private MapView mapView; 
    MapController mc; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.showmap); 

     mapView = (MapView) findViewById(R.id.mapview); 
     mapView.setBuiltInZoomControls(true); 
     mapView.setClickable(true); 

     Drawable marker=getResources().getDrawable(R.drawable.pushpin); 
     marker.setBounds(0, 0, marker.getIntrinsicWidth(), 
     marker.getIntrinsicHeight()); 

     InterestingLocations funPlaces = new InterestingLocations(marker); 
     mapView.getOverlays().add(funPlaces); 
     GeoPoint pt = funPlaces.getCenter(); // get the first-ranked point 
     mapView.getController().setCenter(pt); 
     mapView.getController().setZoom(15); 

    } 
    @Override 
    protected boolean isLocationDisplayed() { 
    return false; 
    } 
    @Override 
    protected boolean isRouteDisplayed() { 
    return false; 
    } 
    class InterestingLocations extends ItemizedOverlay { 
     private List<OverlayItem> locations = new ArrayList<OverlayItem>(); 
     private Drawable marker; 
     String adresa; 
     public InterestingLocations(Drawable marker) 
     { 
     super(marker); 
     this.marker=marker; 
     // create locations of interest 
     Bundle bundle = getIntent().getExtras(); 
     adresa = bundle.getString("adress"); 

     Geocoder geoCoder = new Geocoder(ShowMap.this, Locale.getDefault()); 
     try { 
     List<Address> addresses = geoCoder.getFromLocationName(adresa, 5); 
      String add = ""; 
      if (addresses.size() > 0) { 
       GeoPoint p = new GeoPoint((int) (addresses.get(0).getLatitude() * 1E6), 
         (int) (addresses.get(0).getLongitude() * 1E6)); 

       locations.add(new OverlayItem(p ,"Kaufland", "Magic Kingdom")); 

      } 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } 
     populate(); 
    } 
    @Override 
    public void draw(Canvas canvas, MapView mapView, boolean shadow) { 
    super.draw(canvas, mapView, shadow); 
    boundCenterBottom(marker); 
    } 
    @Override 
    protected OverlayItem createItem(int i) { 
    return locations.get(i); 
    } 
    @Override 
    public int size() { 
    return locations.size(); 
    } 
    } 
}

這裏是logcat的：

06-03 18:36:17.082: ERROR/AndroidRuntime(2296): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.ShoppingList/com.ShoppingList.Shops.ShowMap}: java.lang.NullPointerException 
06-03 18:36:17.082: ERROR/AndroidRuntime(2296):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2496) 
06-03 18:36:17.082: ERROR/AndroidRuntime(2296):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2512) 
06-03 18:36:17.082: ERROR/AndroidRuntime(2296):  at android.app.ActivityThread.access$2200(ActivityThread.java:119) 
06-03 18:36:17.082: ERROR/AndroidRuntime(2296):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1863) 
06-03 18:36:17.082: ERROR/AndroidRuntime(2296):  at android.os.Handler.dispatchMessage(Handler.java:99) 
06-03 18:36:17.082: ERROR/AndroidRuntime(2296):  at android.os.Looper.loop(Looper.java:123) 
06-03 18:36:17.082: ERROR/AndroidRuntime(2296):  at android.app.ActivityThread.main(ActivityThread.java:4363) 
06-03 18:36:17.082: ERROR/AndroidRuntime(2296):  at java.lang.reflect.Method.invokeNative(Native Method) 
06-03 18:36:17.082: ERROR/AndroidRuntime(2296):  at java.lang.reflect.Method.invoke(Method.java:521) 
06-03 18:36:17.082: ERROR/AndroidRuntime(2296):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860) 
06-03 18:36:17.082: ERROR/AndroidRuntime(2296):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618) 
06-03 18:36:17.082: ERROR/AndroidRuntime(2296):  at dalvik.system.NativeStart.main(Native Method) 
06-03 18:36:17.082: ERROR/AndroidRuntime(2296): Caused by: java.lang.NullPointerException 
06-03 18:36:17.082: ERROR/AndroidRuntime(2296):  at com.google.android.maps.MapController.setCenter(MapController.java:345) 
06-03 18:36:17.082: ERROR/AndroidRuntime(2296):  at com.ShoppingList.Shops.ShowMap.onCreate(ShowMap.java:43) 
06-03 18:36:17.082: ERROR/AndroidRuntime(2296):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 
06-03 18:36:17.082: ERROR/AndroidRuntime(2296):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2459) 
06-03 18:36:18.881: INFO/Process(2296): Sending signal. PID: 2296 SIG: 9

來源

2011-06-03 Gaby