Android MapView无法删除标记

概述我正在使用locationManager和ItemizedOverlay绘制“我的位置”标记,问题是当触发onLocationChanged时,我正在绘制新标记,而不是最后一个移到新位置,这是我的onLocationChanged代码：publicvoidonLocationChanged(Locationlocation){myOverlayobject1=newmyOverlay(getRe

我正在使用locationManager和itemizedoverlay绘制“我的位置”标记,问题是当触发onLocationChanged时,我正在绘制新标记,而不是最后一个移到新位置,这是我的onLocationChanged代码：

public voID onLocationChanged(Location location) {  myOverlay object1 = new myOverlay(getResources().getDrawable(R.drawable.arrow),MyMap);  if(location!=null){   MyMap.invalIDate();   GeoPoint MyPos = new GeoPoint(microdegrees(location.getLatitude()),microdegrees(location.getLongitude()));   MyController.animateto(MyPos);   object1.addPoint(MyPos,"Ma position","Ma position");   MyMap.getoverlays().add(object1);  } }

您能帮我解决这个问题吗？

非常感谢.

MapActivity：

public class Main extends MapActivity implements LocationListener {  /** Called when the activity is first created. */  MapVIEw MyMap;  MapController MyController;    @OverrIDe  public voID onCreate(Bundle savedInstanceState) {      super.onCreate(savedInstanceState);      setContentVIEw(R.layout.main);      MyMap=(MapVIEw)findVIEwByID(R.ID.MyGMap);      MyMap.setBuiltInZoomControls(true);      try {      getEventsFromAnXML(this);     } catch (XmlPullParserException e) {      e.printstacktrace();     } catch (IOException e) {      e.printstacktrace();     }     int j=0;     myOverlay object = new myOverlay(getResources().getDrawable(R.drawable.marker),MyMap);     while( j<agencIEs.size()){         GeoPoint point = new GeoPoint(microdegrees(agencIEs.get(j).getLatitude()),microdegrees(agencIEs.get(j).getLongitude()));         String Tit;         String Des;         Tit=agencIEs.get(j).getTspTitle();         Des=agencIEs.get(j).getTspTitle() + "\nAgence: " + agencIEs.get(j).getTitle() +             "\nTél: " + agencIEs.get(j).getPhone();         object.addPoint(point,Tit,Des);         j=j+1;     }     MyMap.getoverlays().add(object);     MyController=MyMap.getController();     MyController.setZoom(12);     LocationManager lm = (LocationManager)getSystemService(Context.LOCATION_SERVICE);     lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000L, 500.0f, this);  }  private int microdegrees(double value){      return (int)(value*1000000);  }  boolean na=false;  List<Agency> agencIEs = new ArrayList<Agency>();  Agency agency=new Agency();  int i=0;  String TempTspTitle;  String TempTspPhone;  Boolean TempTspEnabled;  private String getEventsFromAnXML(Activity activity)  throws XmlPullParserException, IOException  {   StringBuffer stringBuffer = new StringBuffer();   Resources res = activity.getResources();   XmlResourceParser xpp = res.getXml(R.xml.hotels);   xpp.next();   int eventType = xpp.getEventType();   while (eventType != XmlPullParser.END_document)   {    if(eventType == XmlPullParser.START_document)    {     stringBuffer.append("--- Start XML ---");    }    else if(eventType == XmlPullParser.START_TAG)    {        if (xpp.getname().equals("DataBase")){            String name=xpp.getAttributeValue(null, "name");            agency.setTspTitle(name);            TempTspTitle=name;            na=true;        }        if (xpp.getname().equals("DataBaseEnabled")){            xpp.next();            agency.setTspEnabled(Boolean.parseBoolean(xpp.getText()));            TempTspEnabled=Boolean.parseBoolean(xpp.getText());            xpp.nextTag();        }        if (xpp.getname().equals("Title")){            xpp.next();            agency.setTitle(xpp.getText());            na=false;            xpp.nextTag();        }        if (xpp.getname().equals("Address")){            xpp.next();            agency.setAddress(xpp.getText());            xpp.nextTag();        }        if (xpp.getname().equals("Phone") && na==true){            xpp.next();            agency.setTspPhone(xpp.getText());            TempTspPhone=xpp.getText();            xpp.nextTag();        }else{            if (xpp.getname().equals("Phone") && na==false){                xpp.next();                agency.setPhone(xpp.getText());                xpp.nextTag();            }        }        if (xpp.getname().equals("Fax")){            xpp.next();            agency.setFax(xpp.getText());            xpp.nextTag();        }        if (xpp.getname().equals("e-Mail")){            xpp.next();            agency.setMail(xpp.getText());            xpp.nextTag();        }        if (xpp.getname().equals("Latitude")){            xpp.next();            agency.setLatitude(Double.parseDouble(xpp.getText()));            xpp.nextTag();        }        if (xpp.getname().equals("Longitude")){            xpp.next();            agency.setLongitude(Double.parseDouble(xpp.getText()));        }    }    else if(eventType == XmlPullParser.END_TAG)    {        if (xpp.getname().equals("DataBase") ){            agency = new Agency();        }else if (xpp.getname().equals("Agency")){            agencIEs.add(i,agency);            i=i+1;            agency = new Agency();            agency.setTspTitle(TempTspTitle);            agency.setTspPhone(TempTspPhone);            agency.setTspEnabled(TempTspEnabled);        }    }    eventType = xpp.next();   }   stringBuffer.append("\n" + "Size: " + agencIEs.size());   return stringBuffer.toString();  }  @OverrIDe    protected boolean isRoutedisplayed() {        return false;    }    public voID onLocationChanged(Location location) {        myOverlay object1 = new myOverlay(getResources().getDrawable(R.drawable.arrow),MyMap);        if(location!=null){            MyMap.getoverlays().remove(object1);            MyMap.invalIDate();            GeoPoint MyPos = new GeoPoint(microdegrees(location.getLatitude()),microdegrees(location.getLongitude()));            MyController.animateto(MyPos);            object1.addPoint(MyPos,"Ma position","Ma position");            MyMap.getoverlays().add(object1);        }    }    public voID onProvIDerDisabled(String provIDer) {        // Todo auto-generated method stub    }    public voID onProvIDerEnabled(String provIDer) {        // Todo auto-generated method stub    }    public voID onStatusChanged(String provIDer, int status, Bundle extras) {        // Todo auto-generated method stub    }

和myOverlay类：

public class myOverlay extends itemizedoverlay<OverlayItem>{    List<OverlayItem> points= new ArrayList<OverlayItem>();    private Drawable marker=null;      private Context c;    public myOverlay(Drawable marker, MapVIEw mapVIEw) {        super(marker);        this.marker=marker;        c=mapVIEw.getContext();    }    @OverrIDe    protected OverlayItem createItem(int i) {        return (points.get(i));    }    public voID draw(Canvas canvas,MapVIEw mapVIEw, boolean shadow){        super.draw(canvas, mapVIEw, shadow);        boundCenterBottom(marker);    }    @OverrIDe    public int size() {        return points.size();    }    public voID addPoint(GeoPoint point, String Titre, String Desc){        this.points.add(new OverlayItem(point,Titre,Desc));        populate();    }    public voID removePoint(){        this.points.clear();        populate();    }    @OverrIDe    protected boolean onTap(int i){        Toast.makeText(c, points.get(i).getSnippet(), Toast.LENGTH_SHORT).show();        return (true);    }  }          }

解决方法:

根据戴夫的建议,这解决了这个问题：

  public voID onLocationChanged(Location location) {    if(mMyOverlay == null) {        mMyOverlay = new myOverlay(getResources().getDrawable(R.drawable.arrow),MyMap);        MyMap.getoverlays().add(mMyOverlay);    }else{        MyMap.getoverlays().remove(mMyOverlay);        MyMap.invalIDate();        mMyOverlay = new myOverlay(getResources().getDrawable(R.drawable.arrow),MyMap);        MyMap.getoverlays().add(mMyOverlay);    }    if(location!=null){        MyMap.invalIDate();        GeoPoint MyPos = new GeoPoint(microdegrees(location.getLatitude()),microdegrees(location.getLongitude()));        MyController.animateto(MyPos);        mMyOverlay.addPoint(MyPos,"Ma position","Ma position");     }

谢谢..

总结

以上是内存溢出为你收集整理的Android MapView无法删除标记全部内容，希望文章能够帮你解决Android MapView无法删除标记所遇到的程序开发问题。

如果觉得内存溢出网站内容还不错，欢迎将内存溢出网站推荐给程序员好友。