Android中的ConcurrentModificationException

Question

首先我要道歉再問這個問題，但我還沒找到解決方案。

我有一個應用程序，我可以通過MyLocationOverlay找到自己，並使用itemizedOverlay繪製我的朋友的位置。但是隨着ConcurrentModificationExcepion

對於我的位置的應用程序崩潰我用MyLocationOverlay這個單碼（previusly初始化）：

myLocOverlay = new MyLocationOverlay(this, mapView); 
myLocOverlay.enableMyLocation(); 
mapView.getOverlays().add(myLocOverlay); 

對於我的朋友的位置我使用ItemizedOverlay和方法繪製的位置。該ItemizedOverlay是這樣的：

package app.localizadroid.ACT; 

    import java.util.ArrayList; 
    import java.util.List; 
    import java.util.concurrent.CopyOnWriteArrayList; 

    import android.content.Context; 
    import android.graphics.drawable.Drawable; 
    import android.widget.Toast; 

    import com.google.android.maps.MapView; 
    import com.google.android.maps.OverlayItem; 

    public class Tab_Activity_map_HelloItemizedOverlay extends Tab_Activity_map_BalloonItemizedOverlay<OverlayItem> {   

    private List<OverlayItem> mOverlays; 

private Context c; 


public Tab_Activity_map_HelloItemizedOverlay(Drawable defaultMarker, MapView mapView) { 
    super(boundCenter(defaultMarker), mapView); 
    c = mapView.getContext(); 
    mOverlays = new ArrayList(); 
    // TODO Auto-generated constructor stub 
} 

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

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

public void addOverlay(OverlayItem overlay) { 
    mOverlays.add(overlay); 
    populate(); 
} 

public void removeOverlay(OverlayItem overlay) { 
    mOverlays.remove(overlay); 
    populate(); 
} 

public void clear() { 
    mOverlays.clear(); 
    populate(); 
} 

protected boolean onBalloonTap(int index, OverlayItem item) { 
    Toast.makeText(c, "onBalloonTap for overlay index " + index, Toast.LENGTH_LONG).show(); 
    return true; 
} 
} 

這是繪製位置的方法：

public void createAndShowMyItemizedOverlay(Location newLocation, String User, String time) { 
    List overlays = mapView2.getOverlays(); 

    // first remove old overlay 
    if (overlays.size() > 0) { 
     for (Iterator iterator = overlays.iterator(); iterator.hasNext();) { 
      iterator.next(); 
      iterator.remove(); 
     } 
    } 
    // transform the location to a geopoint 
    GeoPoint geopoint = new GeoPoint((int) (newLocation.getLatitude() * 1E6), (int) (newLocation.getLongitude() * 1E6)); 

    // initialize icon 
    Drawable icon = getResources().getDrawable(R.drawable.marker_friends); 
    icon.setBounds(0, 0, icon.getIntrinsicWidth(), icon.getIntrinsicHeight()); 

    // create my overlay and show it 
    //Tab_Activity_map_MyItemizedOverlay overlay= new Tab_Activity_map_MyItemizedOverlay(icon); 
    Tab_Activity_map_HelloItemizedOverlay overlay = new Tab_Activity_map_HelloItemizedOverlay(icon, mapView2); 
    OverlayItem item = new OverlayItem(geopoint, User + "\n" + time, null); 
    overlay.addOverlay(item); 
    //overlay.addItem(item); 
    mapView2.getOverlays().add(overlay); 

    // redraw map 
    mapView2.postInvalidate(); 
} 

使用兩個型動物mapViews（MapView類和mapView2），否則平局方法擦除myLocationOverlay點當它mapView2.postInvalidate();

正如我所說的，我獲得了ConcurrentModificationException。我找到了一些解決方案，但我不知道如何申請......這對我來說很重要，因爲這是我職業生涯結束時的工作。非常感謝！

Answer 1

變化：

// first remove old overlay 
if (overlays.size() > 0) { 
    for (Iterator iterator = overlays.iterator(); iterator.hasNext();) { 
     iterator.next(); 
     iterator.remove(); 
    } 
} 

要：

overlays.clear();