Question

我在如何在地图中显示/绘制位置时遇到问题。我想在每个特定的位置放置一个标记。我创建了sqlite数据库来存储我的数据（MallName，地址，纬度和经度）。一切正常。它从我的sqlite返回值。我用Log测试了它。参见MallMarkers.java

也许我在使用MarkerOptions时犯了一个错误。请帮我。这是我的代码。

类GoogleMapsApiActivity.java

public class GoogleMapsApiActivity extends FragmentActivity implements LocationListener{

private ArrayList<MallMarkers> malls = new ArrayList<MallMarkers>();
private LocationManager locationManager;
private GoogleMap googleMap;
private static final String DEBUG_TAG = "GoogleMapsApiActivity";
private Location myLocation = null;
private UiSettings mapInterface;
private boolean zoom = true;
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10;
private static final long MIN_TIME_BW_UPDATES = 1000*60*1;
private DataSource datasource;
private SQLiteDatabase database;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.map_api);
    zoom = true;
    GooglePlayServicesUtil.isGooglePlayServicesAvailable(getApplicationContext());
}   
private void setUpMapIfNeeded() {
    if (googleMap == null) {
        googleMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap();

        if (googleMap != null) {
            setUpMapSetings();              
        }
    }
}

private void setUpMapSetings(){         
    SharedPreferences sharedMapSettings = PreferenceManager.getDefaultSharedPreferences(this);
    String  mapViewLayout = sharedMapSettings.getString("map_layer", "Normal");
    Boolean mapTraffic = sharedMapSettings.getBoolean("key_mapTraffic", false);
    Boolean mapCompass = sharedMapSettings.getBoolean("key_mapCompass", true);
    boolean mapMyLocation = sharedMapSettings.getBoolean("key_mapMyLocation", true);
    boolean mapButtonZoom = sharedMapSettings.getBoolean("key_mapButtonZoom", true);
    mapInterface = googleMap.getUiSettings();
    //plotMalls();
    if(mapViewLayout.equals("Normal")){
        googleMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
    }
    else if(mapViewLayout.equals("Hybrid")){
        googleMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
    }
    else if(mapViewLayout.equals("Satellite")){
        googleMap.setMapType(GoogleMap.MAP_TYPE_SATELLITE);
    }
    else if(mapViewLayout.equals("Terrain")){
        googleMap.setMapType(GoogleMap.MAP_TYPE_TERRAIN);
    }

    googleMap.setTrafficEnabled(mapTraffic);
    mapInterface.setCompassEnabled(mapCompass);
    mapInterface.setMyLocationButtonEnabled(mapMyLocation);
    mapInterface.setZoomControlsEnabled(mapButtonZoom);

    googleMap.getUiSettings().setAllGesturesEnabled(true);
    googleMap.setMyLocationEnabled(true);
}  
//I used cursor to query my data from sqlite (Works fine)
private void plotLocationMallMapsUI(){
    database=openOrCreateDatabase(com.example.sqlite.MySQLiteHelper.DATABASE_NAME, Context.MODE_PRIVATE, null);
    String sqlcommand = "SELECT MallName, MallStreetAddress, MallCityAddress, MallContactNumber, MallLatitude, MallLongitude FROM mallsinfo";
    Cursor cursor = database.rawQuery(sqlcommand, null);
    malls = new ArrayList<MallMarkers>();
    if(cursor.moveToFirst()){       
        do{
            MallMarkers markers = new MallMarkers(cursor.getString(0),
            cursor.getString(1),
            cursor.getString(2),
            cursor.getString(3),
            cursor.getString(4),
            cursor.getString(5), this);
            malls.add(markers);
        }while(cursor.moveToNext());        
    }
    cursor.close();
    database.close();
}

@Override
public void onRestart() {
    super.onRestart(); 
    setUpMapSetings();
}
@Override 
public void onResume() {
    super.onResume();
    setUpMapIfNeeded();
    plotLocationMallMapsUI();

}
@Override
public void onPause() {
    locationManager.removeUpdates(this);
    super.onPause();
}
@Override
public void onLocationChanged(Location location) {
    LatLng latlng = new LatLng(location.getLatitude(), location.getLongitude());
    locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    Criteria criteria = new Criteria();
    provider = locationManager.getBestProvider(criteria, false);
    location = locationManager.getLastKnownLocation(provider);
    double lat = (double) (location.getLatitude());
    double lng = (double) (location.getLongitude());
    Log.d(DEBUG_TAG, "Latitude: " + String.valueOf(lat));
    Log.d(DEBUG_TAG, "Longitude: " + String.valueOf(lng));
}
@Override
public void onProviderDisabled(String provider) {

}
@Override
public void onProviderEnabled(String provider) {

} 
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {

}

}

它从sqlite返回值。我用Log测试了它。但它没有显示图。请帮帮我。如何使用标记显示它？

Class MallMarkers.java

public class MallMarkers {
private String mMallId = "";
private String mMallName = "";
private String mMallStreetAddress = "";
private String mMallCityAddress = "";
private String mMallContactNumber = "";
private String mMallLatitude = "";
private String mMallLongitude = "";
private Context mContext;
private LatLng mMallCoordinates = null;
private MarkerOptions mMallMarkerOptions=null;
private Double mLatitude;
private Double mLongitude;
private GoogleMap googlemap;
public MallMarkers(String mallname, String mallstreetaddress, String mallcityaddress, String mallcontactnumber, String malllatitude, String malllongitude, Context context){
    mContext = context;
    mMallName = mallname;
    mMallStreetAddress = mallstreetaddress;
    mMallCityAddress = mallcityaddress;
    mMallContactNumber = mallcontactnumber;
    mMallLatitude = malllatitude;
    mMallLongitude = malllongitude;
    mLatitude = Double.parseDouble(mMallLatitude);
    mLongitude = Double.parseDouble(mMallLongitude);

    String FilterMallName;
    String FilterMallStreetAddress;
    String FilterMallCityAddress;
    String FilterMallContacts;
        if(mMallName.equals("")){
            FilterMallName = "Blank";
        }else{
            FilterMallName = mMallName;
        }

        if(mMallStreetAddress.equals("")){
            FilterMallStreetAddress = "Blank";
        }else{
            FilterMallStreetAddress = mMallStreetAddress;
        }

        if(mMallCityAddress.equals("")){
            FilterMallCityAddress = "Blank";
        }else{
            FilterMallCityAddress = mMallCityAddress;
        }

        if(mMallContactNumber.equals("")){
            FilterMallContacts = "Blank";
        }else{
            FilterMallContacts = mMallContactNumber;
        }


        Log.d("TAG", FilterMallName + ", \n"
                + FilterMallStreetAddress + ", \n" 
                + FilterMallCityAddress+ ", \n" 
                + FilterMallContacts + "\n" 
                + String.valueOf(mLatitude) + " ," + String.valueOf(mLongitude) 
                + "\n------------------------\n");

        mMallCoordinates = new LatLng(mLatitude, mLongitude);
        mMallMarkerOptions = new MarkerOptions();
        mMallMarkerOptions.position(mMallCoordinates);
        mMallMarkerOptions.title(FilterMallName);
        mMallMarkerOptions.snippet(FilterMallStreetAddress + ", " + FilterMallCityAddress + ", " + FilterMallContacts);
        mMallMarkerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED));

}

}

Answer 1

这是一个循环，我在地图上设置标记，它对我很有用：

for (Task tempTask : TasksListAppObj.getInstance().tasksRepository.getTasksRepository())
                {
                    LatLng latlng = new LatLng(tempTask.getLatitude(), tempTask.getLongtitude());
                    if (tempTask.getStatus().contentEquals(TasksListActivity.STATUS_WAITING))
                    {
                        newmarker = map.addMarker(new MarkerOptions().position(latlng).title(tempTask.getTitle()).icon(BitmapDescriptorFactory.fromResource(R.drawable.marker_for_map_blue)));
                    }
                    else if (tempTask.getStatus().contentEquals(TasksListActivity.STATUS_IN_PROGRESS))
                    {
                        newmarker = map.addMarker(new MarkerOptions().position(latlng).title(tempTask.getTitle()).icon(BitmapDescriptorFactory.fromResource(R.drawable.marker_for_map_bordo)));
                    }
                    else if (tempTask.getStatus().contentEquals(TasksListActivity.STATUS_ON_THE_WAY))
                    {
                        newmarker = map.addMarker(new MarkerOptions().position(latlng).title(tempTask.getTitle()).icon(BitmapDescriptorFactory.fromResource(R.drawable.marker_for_map_turkiz)));
                    }
                    else if (tempTask.getStatus().contentEquals(TasksListActivity.STATUS_COMPLETE))
                    {
                        newmarker = map.addMarker(new MarkerOptions().position(latlng).title(tempTask.getTitle()).icon(BitmapDescriptorFactory.fromResource(R.drawable.marker_for_map_orange)));
                    }
                    else if (tempTask.getStatus().contentEquals(TasksListActivity.STATUS_FAILED))
                    {
                        newmarker = map.addMarker(new MarkerOptions().position(latlng).title(tempTask.getTitle()).icon(BitmapDescriptorFactory.fromResource(R.drawable.marker_for_map_purpul)));
                    }
}

看看它是否对你有帮助。

if语句用于更改标记图标。

您缺少的是应用于地图的addMarker方法，以便将Marker对象实际添加到GoogleMap对象。

Answer 2

在plotLocationMallMapsUI()

之后的database.close()中尝试这样的事情

    for  (MallMarkers mm : malls) {
        Marker marker = googlemap.addMarker(new MarkerOptions().position(mm.getmalllatitude, mm.getmalllongitude));
    }

如何在Android Google Maps API v2中使用MarkerOptions显示/绘制位置

2 个答案: