向OSMDROID添加覆盖

Question

我已经为此挣扎了很长时间。我正在尝试在我的地图上添加叠加。我使用的是开源的OSMdroid。但是我在这个例子中得到的只是一条从一个角落到另一个角落的直线红线。我的目标是在我的geoPoint设置的地方添加一些图标。

下面是我的代码：

 package osmdemo.demo;

import java.util.List;

import microsoft.mappoint.TileSystem;

import org.osmdroid.tileprovider.tilesource.TileSourceFactory;
import org.osmdroid.util.GeoPoint;
import org.osmdroid.views.MapController;
import org.osmdroid.views.MapView;
import org.osmdroid.views.MapView.Projection;
import org.osmdroid.views.overlay.Overlay;
import org.osmdroid.views.overlay.ScaleBarOverlay;
import org.osmdroid.views.util.constants.MapViewConstants;

import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Paint.Style;
import android.graphics.Rect;
import android.location.LocationManager;
import android.os.Bundle;

public class map extends Activity implements MapViewConstants
{

    /** Called when the activity is first created. */

    protected static final String PROVIDER_NAME = LocationManager.GPS_PROVIDER;
    MapController mapController;
    MapView mapView;
    ScaleBarOverlay mScaleBarOverlay;
    private MapOverlay mmapOverlay = null;
    private LocationManager mLocMgr;

    @Override
    public void onCreate(Bundle savedInstanceState)
    {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        mapView = (MapView) findViewById(R.id.mapview);

        mapView.setTileSource(TileSourceFactory.MAPNIK);
        mapView.setBuiltInZoomControls(true);
        mapView.setMultiTouchControls(true);

        mapController = mapView.getController();
        mapController.setZoom(20);
        GeoPoint point2 = new GeoPoint(31.987968, 34.783069);
        mapController.setCenter(point2);

        this.mmapOverlay = new MapOverlay(this);

        List<Overlay> listOfOverlays = mapView.getOverlays();
        listOfOverlays.add(mmapOverlay);
        mapView.invalidate();
    }

    public class MapOverlay extends org.osmdroid.views.overlay.Overlay
    {

        public MapOverlay(Context ctx)
        {
            super(ctx);
            // TODO Auto-generated constructor stub
        }

        @Override
        protected void draw(Canvas pC, MapView pOsmv, boolean shadow)
        {
            if (shadow)
                return;

            Paint lp3;
            lp3 = new Paint();
            lp3.setColor(Color.RED);
            lp3.setAntiAlias(true);
            lp3.setStyle(Style.STROKE);
            lp3.setStrokeWidth(1);
            lp3.setTextAlign(Paint.Align.LEFT);
            lp3.setTextSize(12);
            // Calculate the half-world size
            final Rect viewportRect = new Rect();
            final Projection projection = pOsmv.getProjection();
            final int zoomLevel = projection.getZoomLevel();
            int mWorldSize_2 = TileSystem.MapSize(zoomLevel) / 2;

            // Save the Mercator coordinates of what is on the screen
            viewportRect.set(projection.getScreenRect());
            // DON'T set offset with either of below
            // viewportRect.offset(-mWorldSize_2, -mWorldSize_2);
            // viewportRect.offset(mWorldSize_2, mWorldSize_2);

            // Draw a line from one corner to the other
            pC.drawLine(viewportRect.left, viewportRect.top,
                    viewportRect.right, viewportRect.bottom, lp3);
        }

        public void onProviderDisabled(String arg0)
        {
        }

        public void onProviderEnabled(String provider)
        {
        }

    }

}

这是我的宣言：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.test.overlay" android:versionCode="1" android:versionName="1.0">
    <uses-sdk android:minSdkVersion="3" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />


    <application >
        <activity android:name=".OverlayDemo" android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    </application>
</manifest>

提前谢谢你，

雷。

Answer 1

自从编写示例代码以来，jars版本3.0.3和3.0.4似乎发生了一些变化。

如果您的应用程序基于前面答案中引用的代码，请更改该行

mResourceProxy = new ResourceProxyImpl(getApplicationContext());

至

mResourceProxy = new DefaultResourceProxyImpl(getApplicationContext());

这至少可以让你使用一个默认的图标。

编辑

这将使利物浦的地图位于东北方向，并放置一个偏离中心的图标。

package osmdemo.demo;

import java.util.ArrayList;
import org.osmdroid.DefaultResourceProxyImpl;
import org.osmdroid.ResourceProxy;
import org.osmdroid.tileprovider.tilesource.TileSourceFactory;
import org.osmdroid.util.GeoPoint;
import org.osmdroid.views.MapController;
import org.osmdroid.views.MapView;
import org.osmdroid.views.overlay.ItemizedIconOverlay;
import org.osmdroid.views.overlay.ItemizedOverlay;
import org.osmdroid.views.overlay.OverlayItem;
import org.osmdroid.views.util.constants.MapViewConstants;

import android.app.Activity;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.widget.Toast;

public class DemoMap extends Activity implements LocationListener,
        MapViewConstants {

    private MapView mMapView;
    private MapController mapController;
    private LocationManager mLocMgr;
    private ItemizedOverlay<OverlayItem> mMyLocationOverlay;
    private ResourceProxy mResourceProxy;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        mResourceProxy = new DefaultResourceProxyImpl(getApplicationContext());
        setContentView(R.layout.copymain);

        mMapView = (MapView) this.findViewById(R.id.mapview);
        mMapView.setTileSource(TileSourceFactory.MAPNIK);
        mMapView.setBuiltInZoomControls(true);
        mMapView.setMultiTouchControls(true);
        mapController = this.mMapView.getController();
        mapController.setZoom(15);
        GeoPoint point2 = new GeoPoint(53554070, -2959520); // centre map here
        GeoPoint point3 = new GeoPoint(53554070 + 1000, -2959520 + 1000); // icon goes here
        mapController.setCenter(point2);
        mLocMgr = (LocationManager) getSystemService(LOCATION_SERVICE);
        mLocMgr.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000, 100,
                this);

        ArrayList<OverlayItem> items = new ArrayList<OverlayItem>();
        // Put overlay icon a little way from map centre
        items.add(new OverlayItem("Here", "SampleDescription", point3));

        /* OnTapListener for the Markers, shows a simple Toast. */
        this.mMyLocationOverlay = new ItemizedIconOverlay<OverlayItem>(items,
                new ItemizedIconOverlay.OnItemGestureListener<OverlayItem>() {
                    @Override
                    public boolean onItemSingleTapUp(final int index,
                            final OverlayItem item) {
                        Toast.makeText(
                                DemoMap.this,
                                "Item '" + item.mTitle, Toast.LENGTH_LONG).show();
                        return true; // We 'handled' this event.
                    }
                    @Override
                    public boolean onItemLongPress(final int index,
                            final OverlayItem item) {
                        Toast.makeText(
                                DemoMap.this, 
                                "Item '" + item.mTitle ,Toast.LENGTH_LONG).show();
                        return false;
                    }
                }, mResourceProxy);
        this.mMapView.getOverlays().add(this.mMyLocationOverlay);
        mMapView.invalidate();
    }

    public void onLocationChanged(Location location) {
        int lat = (int) (location.getLatitude() * 1E6);
        int lng = (int) (location.getLongitude() * 1E6);
        GeoPoint gpt = new GeoPoint(lat, lng);
        mapController.setCenter(gpt);
        mMapView.invalidate();
    }

    @Override
    public void onProviderDisabled(String arg0) {}
    @Override
    public void onProviderEnabled(String provider) {}
    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {}

}

它有点粗糙和准备好了，但至少它可以在3.0.4JAR和slf4j中运行良好。希望能有所帮助。

编辑2个

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="osmdemo.demo"
      android:versionCode="1"
      android:versionName="1.0">
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name="DemoMap"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    </application>
    <uses-sdk android:minSdkVersion="3" />

    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/> 
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

</manifest> 

。

Answer 2

如果您正在尝试添加图标，那么您需要查看ItemizedOverlay类。您可以使用osmdroid的ItemizedIconOverlay，它是ItemizedOverlay的一个具体实现，也可以自己继承ItemizedOverlay的子类。请看示例，例如：

http://code.google.com/p/osmdroid/source/browse/trunk/OpenStreetMapViewer/src/org/osmdroid/samples/SampleWithMinimapItemizedoverlay.java

Answer 3

@rayman

请再说一件事。当位置发生变化时，地图会发生变化，但图标会消失。如何在新更改中验证图标？- rayman Jul 1 '11 at 7:12

这就是你的位置改变的地方

public void onLocationChanged(Location location) {
    int lat = (int) (location.getLatitude() * 1E6);
    int lng = (int) (location.getLongitude() * 1E6);
    GeoPoint gpt = new GeoPoint(lat, lng);
    mapController.setCenter(gpt);
    mMapView.invalidate();
}

但是正如你所看到的，它并没有添加新的图标到覆盖中。

您应该清除前面的项目

items.clear()

(如果您希望在创建新图标时删除“旧”图标)，然后将新的点(gpt)添加到项目中。

items.add(new OverlayItem("Title", "Description", gpt));

以此类推。