我现在正致力于在地图上绘制公共汽车和公共汽车站的绘图。一个任务是获取用户的当前位置，并在应用程序暂停时停止更新，并在应用程序恢复时继续更新。此外，位置更新最多每10秒发生一次，或者位置变化至少25米。我需要在地图上绘制用户的当前位置。
这是MapDisplayFragment的代码。这里添加了OverlayItems（包括表示用户位置的OverlayItem），似乎我需要创建新的类来实现这些功能，而不是像我所做的那样在这个类中编写代码。我正在考虑构建两个类：扩展LocationListener的MyLocationListener和扩展Fragment的MyLocationFragment，但现在我不知道如何开始：更具体地说，我不知道我应该建立这些类之间的关系。有什么想法吗？
import java.util.ArrayList;
import java.util.List;
import org.osmdroid.DefaultResourceProxyImpl;
import org.osmdroid.ResourceProxy;
import org.osmdroid.api.IMapController;
import org.osmdroid.tileprovider.tilesource.TileSourceFactory;
import org.osmdroid.util.GeoPoint;
import org.osmdroid.views.MapView;
import org.osmdroid.views.overlay.ItemizedIconOverlay;
import org.osmdroid.views.overlay.ItemizedIconOverlay.OnItemGestureListener;
import org.osmdroid.views.overlay.OverlayItem;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.res.Resources;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationManager;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import ca.ubc.cpsc210.exception.TranslinkException;
import ca.ubc.cpsc210.nextbus.model.Bus;
import ca.ubc.cpsc210.nextbus.model.BusStop;
import ca.ubc.cpsc210.nextbus.translink.ITranslinkService;
import ca.ubc.cpsc210.nextbus.translink.TranslinkService;
import ca.ubc.cpsc210.nextbus.util.LatLon;
import ca.ubc.cpsc210.nextbus.util.TextOverlay;
/**
* Fragment holding the map in the UI.
*/
public class MapDisplayFragment extends Fragment {
/**
* Log tag for LogCat messages
*/
private final static String LOG_TAG = "MapDisplayFragment";
/**
* Location of Nelson & Granville, downtown Vancouver
*/
private final static GeoPoint NELSON_GRANVILLE
= new GeoPoint(49.279285, -123.123007);
/**
* Overlay for bus markers.
*/
private ItemizedIconOverlay<OverlayItem> busLocnOverlay;
/**
* Overlay for bus stop location
*/
private ItemizedIconOverlay<OverlayItem> busStopLocationOverlay;
/**
* Overlay for legend
*/
private TextOverlay legendOverlay;
/**
* View that shows the map
*/
private MapView mapView;
/**
* Selected bus stop
*/
private BusStop selectedStop;
/**
* Wraps Translink web service
*/
private ITranslinkService tlService;
/**
* Map controller for zooming in/out, centering
*/
private IMapController mapController;
/**
* True if and only if map should zoom to fit displayed route.
*/
private boolean zoomToFit;
/**
* Bus selected by user
*/
private OverlayItem selectedBus;
/**
* User's location icon.
*/
private OverlayItem userLocnIcon;
/**
* Overlay for user current location.
*/
private ItemizedIconOverlay<OverlayItem> userLocnOverlay;
/**
* User's location.
*/
private GeoPoint location;
/**
* Set up Translink service
*/
@Override
public void onCreate(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
Log.d(LOG_TAG, "onActivityCreated");
setHasOptionsMenu(true);
tlService = new TranslinkService(getActivity());
Log.d(LOG_TAG, "Stop number for mapping: " + (selectedStop == null ? "not set" : selectedStop.getStopNum()));
}
/**
* Set up map view with overlays for buses and selected bus stop.
*/
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
Log.d(LOG_TAG, "onCreateView");
if (mapView == null) {
mapView = new MapView(getActivity(), null);
mapView.setTileSource(TileSourceFactory.MAPNIK);
mapView.setClickable(true);
mapView.setBuiltInZoomControls(true);
// set default view for map (this seems to be important even when
// it gets overwritten by plotBuses)
mapController = mapView.getController();
mapController.setZoom(mapView.getMaxZoomLevel() - 4);
mapController.setCenter(NELSON_GRANVILLE);
busLocnOverlay = createBusLocnOverlay();
busStopLocationOverlay = createBusStopLocnOverlay();
legendOverlay = createTextOverlay();
userLocnOverlay = createUserLocnOverlay();
// Order matters: overlays added later are displayed on top of
// overlays added earlier.
mapView.getOverlays().add(busStopLocationOverlay);
mapView.getOverlays().add(busLocnOverlay);
mapView.getOverlays().add(userLocnOverlay);
mapView.getOverlays().add(legendOverlay);
}
return mapView;
}
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
super.onCreateOptionsMenu(menu, inflater);
inflater.inflate(R.menu.fragment_map_refresh, menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == R.id.map_refresh) {
update(false);
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* When view is destroyed, remove map view from its parent so that it can be
* added again when view is re-created.
*/
@Override
public void onDestroyView() {
Log.d(LOG_TAG, "onDestroyView");
((ViewGroup) mapView.getParent()).removeView(mapView);
super.onDestroyView();
}
@Override
public void onDestroy() {
Log.d(LOG_TAG, "onDestroy");
super.onDestroy();
}
/**
* Update bus locations.
*/
@Override
public void onResume() {
Log.d(LOG_TAG, "onResume");
update(true);
super.onResume();
}
/**
* Set selected bus stop
* @param selectedStop the selected stop
*/
public void setBusStop(BusStop selectedStop) {
this.selectedStop = selectedStop;
}
/**
* Update bus location info for selected stop,
* zoomToFit status and repaint.
*
* @Param zoomToFit true if map must be zoomed to fit (when new bus stop has been selected)
*/
void update(boolean zoomToFit) {
Log.d(LOG_TAG, "update - zoomToFit: " + zoomToFit);
this.zoomToFit = zoomToFit;
if(selectedStop != null) {
new GetBusInfo().execute(selectedStop);
selectedBus = null;
}
mapView.invalidate();
}
/**
* Create the overlay for bus markers.
*/
private ItemizedIconOverlay<OverlayItem> createBusLocnOverlay() {
ResourceProxy rp = new DefaultResourceProxyImpl(getActivity());
OnItemGestureListener<OverlayItem> gestureListener = new OnItemGestureListener<OverlayItem>() {
/**
* Display bus information in dialog box when user taps
* bus.
*
* @param index index of item tapped
* @param oi the OverlayItem that was tapped
* @return true to indicate that tap event has been handled
*/
@Override
public boolean onItemSingleTapUp(int index, OverlayItem oi) {
AlertDialog dlg = createSimpleDialog(oi.getTitle(), oi.getSnippet());
dlg.show();
if(selectedBus != null){
selectedBus.setMarker(getResources().getDrawable(R.drawable.bus));
}
selectedBus = oi;
selectedBus.setMarker(getResources().getDrawable(R.drawable.selected_bus));
mapView.postInvalidate();
return true;
}
@Override
public boolean onItemLongPress(int index, OverlayItem oi) {
// do nothing
return false;
}
};
return new ItemizedIconOverlay<OverlayItem>(
new ArrayList<OverlayItem>(),
getResources().getDrawable(R.drawable.bus),
gestureListener, rp);
}
/**
* Create the overlay for bus stop marker.
*/
private ItemizedIconOverlay<OverlayItem> createBusStopLocnOverlay() {
ResourceProxy rp = new DefaultResourceProxyImpl(getActivity());
OnItemGestureListener<OverlayItem> gestureListener = new OnItemGestureListener<OverlayItem>() {
/**
* Display bus stop description in dialog box when user taps
* stop.
*
* @param index index of item tapped
* @param oi the OverlayItem that was tapped
* @return true to indicate that tap event has been handled
*/
@Override
public boolean onItemSingleTapUp(int index, OverlayItem oi) {
AlertDialog dlg = createSimpleDialog(oi.getTitle(), oi.getSnippet());
dlg.show();
return true;
}
@Override
public boolean onItemLongPress(int index, OverlayItem oi) {
// do nothing
return false;
}
};
return new ItemizedIconOverlay<OverlayItem>(
new ArrayList<OverlayItem>(),
getResources().getDrawable(R.drawable.stop),
gestureListener, rp);
}
private TextOverlay createTextOverlay() {
ResourceProxy rp = new DefaultResourceProxyImpl(getActivity());
Resources res = getResources();
String legend = res.getString(R.string.legend);
return new TextOverlay(rp, legend);
}
/**
* Create the overlay for user location markers.
*/
private ItemizedIconOverlay<OverlayItem> createUserLocnOverlay() {
ResourceProxy rp = new DefaultResourceProxyImpl(getActivity());
OnItemGestureListener<OverlayItem> gestureListener = new OnItemGestureListener<OverlayItem>() {
/**
* Display user location.
*
* @param index index of item tapped
* @param oi the OverlayItem that was tapped
* @return true to indicate that tap event has been handled
*/
@Override
public boolean onItemSingleTapUp(int index, OverlayItem oi) {
// Don't do anything.
return false;
}
@Override
public boolean onItemLongPress(int index, OverlayItem oi) {
// do nothing
return false;
}
};
return new ItemizedIconOverlay<OverlayItem>(
new ArrayList<OverlayItem>(),
getResources().getDrawable(R.drawable.map_pin_blue),
gestureListener, rp);
}
/**
* Plot bus stop
*/
private void plotBusStop() {
LatLon latlon = selectedStop.getLatLon();
GeoPoint point = new GeoPoint(latlon.getLatitude(),
latlon.getLongitude());
OverlayItem overlayItem = new OverlayItem(Integer.valueOf(selectedStop.getStopNum()).toString(),
selectedStop.getLocationDesc(), point);
busStopLocationOverlay.removeAllItems(); // make sure not adding
// bus stop more than once
busStopLocationOverlay.addItem(overlayItem);
}
/**
* Plot buses onto bus location overlay
*
* @param zoomToFit determines if map should be zoomed to bounds of plotted buses
*/
private void plotBuses(boolean zoomToFit) {
List<Bus> buses = selectedStop.getBuses();
Double maxlatSpan = 0.0;
Double maxlonSpan = 0.0;
busLocnOverlay.removeAllItems();
for(Bus b : buses){
Double latDifference = Math.abs(b.getLatLon().getLatitude()-NELSON_GRANVILLE.getLatitude() );
if(latDifference > maxlatSpan && (latDifference < 2.0)){
maxlatSpan = latDifference;
}
Double lonDifference = Math.abs(b.getLatLon().getLongitude()-NELSON_GRANVILLE .getLongitude());
if(lonDifference > maxlonSpan && (lonDifference < 2.0)){
maxlonSpan = lonDifference;
}
String routeNo = b.getRoute().getName();
String desc = b.getDescription();
LatLon latlon = b.getLatLon();
GeoPoint point = new GeoPoint(latlon.getLatitude(), latlon.getLongitude());
OverlayItem overlayItem = new OverlayItem(routeNo, desc, point);
busLocnOverlay.addItem(overlayItem);
}
if(zoomToFit){
mapController.zoomToSpan((int)Math.abs(maxlatSpan*2E6), (int) Math.abs(maxlonSpan*2E6));
}
}
/**
* Helper to create simple alert dialog to display message
* @param title the title to be displayed at top of dialog
* @param msg message to display in dialog
* @return the alert dialog
*/
private AlertDialog createSimpleDialog(String title, String msg) {
AlertDialog.Builder dialogBldr = new AlertDialog.Builder(getActivity());
dialogBldr.setTitle(title);
dialogBldr.setMessage(msg);
dialogBldr.setNeutralButton(R.string.ok, null);
return dialogBldr.create();
}
public void getUserLocation() {
Criteria criteria = new Criteria();
Context cont = new Activity();
LocationManager locationManager = (LocationManager) getActivity().getSystemService(Context.LOCATION_SERVICE);
String bestProvider = locationManager.getBestProvider(criteria, true);
Location userLocation = locationManager.getLastKnownLocation(bestProvider);
location = new GeoPoint(userLocation.getLatitude() * 1E6, userLocation.getLongitude() * 1E6);
}
private void plotUserLocation() {
getUserLocation();
userLocnIcon = new OverlayItem("UserLocn", "User location", location);
userLocnOverlay.addItem(userLocnIcon);
}
/**
* Asynchronous task to get bus location estimates from Translink service.
* Displays progress dialog while running in background.
*/
private class GetBusInfo extends
AsyncTask<BusStop, Void, Void> {
private ProgressDialog dialog = new ProgressDialog(getActivity());
private boolean success = true;
@Override
protected void onPreExecute() {
dialog.setMessage("Retrieving bus info...");
dialog.show();
}
@Override
protected Void doInBackground(BusStop... selectedStops) {
BusStop selectedStop = selectedStops[0];
try {
tlService.addBusLocationsForStop(selectedStop);
} catch (TranslinkException e) {
e.printStackTrace();
success = false;
}
return null;
}
@Override
protected void onPostExecute(Void dummy) {
dialog.dismiss();
if (success) {
plotBuses(zoomToFit);
plotBusStop();
plotUserLocation();
mapView.invalidate();
} else {
AlertDialog dialog = createSimpleDialog("Error", "Unable to retrieve bus location info...");
dialog.show();
}
}
}
}
感谢任何帮助。
答案 0 :(得分：0)
我遇到了同样的问题，但在google上搜索后，我发现mapview已被弃用了。因此，您必须使用地图片段并扩展fragmentActivity而不是mapactivity