Not displaying polyline on the map

[thilibu]

Hello every one. I'm new to ArcGIS and I want to add path(polyline) on the map after  giving coordinates where to draw. I follow the guide Display Information -> add graphics and text. But not displaying the path and even not occur any error.

MapView mMapView = null;

    // The basemap switching menu items.

    MenuItem mStreetsMenuItem = null;

    MenuItem mTopoMenuItem = null;

    MenuItem mGrayMenuItem = null;

    MenuItem mOceansMenuItem = null;

    // Create MapOptions for each type of basemap.

    final MapOptions mTopoBasemap = new MapOptions(MapType.TOPO);

    final MapOptions mStreetsBasemap = new MapOptions(MapType.STREETS);

    final MapOptions mGrayBasemap = new MapOptions(MapType.GRAY);

    final MapOptions mOceansBasemap = new MapOptions(MapType.OCEANS);

    ArcGISTiledMapServiceLayer tms = new ArcGISTiledMapServiceLayer("http://services.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer");

    // The current map extent, use to set the extent of the map after switching basemaps.

    Polygon mCurrentMapExtent = null;

    GraphicsLayer mLocationLayer;

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_gis2);

        // Retrieve the map and initial extent from XML layout

        mMapView = (MapView) findViewById(R.id.map);

        mLocationLayer = new GraphicsLayer();

        mMapView.addLayer(tms);

        // Set the Esri logo to be visible, and enable map to wrap around date line.

        mMapView.setEsriLogoVisible(false);

        mMapView.enableWrapAround(true);

       SimpleLineSymbol lineSymbol = new SimpleLineSymbol(Color.GREEN, 3, SimpleLineSymbol.STYLE.DASH);

     Polyline lineGeometry = new Polyline();

     lineGeometry.startPath(-302557, 7570663);

     lineGeometry.lineTo(-302959, 7570868);

     lineGeometry.lineTo(-303042, 7571220);

     lineGeometry.lineTo(-302700, 7571803);

     lineGeometry.lineTo(-304043, 7576654);

     lineGeometry.lineTo(-300544, 7585289);

     lineGeometry.lineTo(-294365, 7592435);

     lineGeometry.lineTo(-290122, 7594445);

     lineGeometry.lineTo(-285283, 7595488); 

     Graphic lineGraphic = new Graphic(lineGeometry, lineSymbol);

     mLocationLayer.addGraphic(lineGraphic);

        // Set a listener for map status changes; this will be called when switching basemaps.

        mMapView.setOnStatusChangedListener(new OnStatusChangedListener() {

            private static final long serialVersionUID = 1L;

            @Override

            public void onStatusChanged(Object source, STATUS status) {

                // Set the map extent once the map has been initialized, and the basemap is added

                // or changed; this will be indicated by the layer initialization of the basemap layer. As there is only

                // a single layer, there is no need to check the source object.

                if ((source == mMapView) && (status == STATUS.INITIALIZED)) {

                    boolean mIsMapLoaded = true;

                }

            }

        });

    }

    @Override

    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items from the Menu XML to the action bar, if present.

        getMenuInflater().inflate(R.menu.menu_gis2, menu);

        // Get the basemap switching menu items.

        mStreetsMenuItem = menu.getItem(0);

        mTopoMenuItem = menu.getItem(1);

        mGrayMenuItem = menu.getItem(2);

        mOceansMenuItem = menu.getItem(3);

        // Also set the topo basemap menu item to be checked, as this is the default.

        mTopoMenuItem.setChecked(true);

        return true;

    }

    @Override

    public boolean onOptionsItemSelected(MenuItem item) {

        // Save the current extent of the map before changing the map.

        // mCurrentMapExtent = mMapView.getExtent();

        // Handle menu item selection.

        switch (item.getItemId()) {

            case R.id.World_Street_Map:

                mMapView.setMapOptions(mStreetsBasemap);

                mStreetsMenuItem.setChecked(true);

                return true;

            case R.id.World_Topo:

                mMapView.setMapOptions(mTopoBasemap);

                mTopoMenuItem.setChecked(true);

                return true;

            case R.id.Gray:

                mMapView.setMapOptions(mGrayBasemap);

                mGrayMenuItem.setChecked(true);

                return true;

            case R.id.Ocean_Basemap:

                mMapView.setMapOptions(mOceansBasemap);

                mOceansMenuItem.setChecked(true);

                return true;

            default:

                return super.onOptionsItemSelected(item);

        }

    }

    @Override

    protected void onPause() {

        super.onPause();

        mMapView.pause();

    }

    @Override

    protected void onResume() {

        super.onResume();

        mMapView.unpause();

   }

Please help me on this. Thank you

[ÅsaWegelius]

I had the same problem (actually today like you ) and it occurs when the spatial references are not the same. This is how I solved it:

1. Make a field for the maps spatial reference

private SpatialReference mapSpatialReference;

2. Save the maps spatial reference in onCreateView. You need to do it this way to be sure the map is fully initialized before you try to get the value.

        mapView = (MapView) view.findViewById(R.id.map);

        mapView.setOnStatusChangedListener(new OnStatusChangedListener() {

            private static final long serialVersionUID = 1L;

            public void onStatusChanged(Object source, STATUS status) {

                if (OnStatusChangedListener.STATUS.INITIALIZED == status && source == mapView) {

                    mapSpatialReference = mapView.getSpatialReference();

                }

            }

        });

3. Check if the spatial references match and use a GeometryEngine to fix it if not.

        if(route != null) {

            locationDisplayManager.stop();

            for (Graphic graphic : route.getGraphics()) {

                if (route.getSpatialReference().equals(mapSpatialReference)) {

                    SimpleLineSymbol lineSymbol = new SimpleLineSymbol(R.color.orange, 5, SimpleLineSymbol.STYLE.SOLID);

                    Polyline poly = (Polyline)graphic.getGeometry();

                    Graphic routeGraphic = new Graphic(poly, lineSymbol);

                    myGraphicsLayer.addGraphic(routeGraphic);

                    mapView.setExtent(routeGraphic.getGeometry(), 15);

                }

                else{

                    SimpleLineSymbol lineSymbol = new SimpleLineSymbol(R.color.orange, 5, SimpleLineSymbol.STYLE.SOLID);

                    GeometryEngine engine = new GeometryEngine();

                    Polyline poly = (Polyline)engine.project(graphic.getGeometry(), route.getSpatialReference(), mapSpatialReference);

                    Graphic routeGraphic = new Graphic(poly, lineSymbol);

                    myGraphicsLayer.addGraphic(routeGraphic);

                    mapView.setExtent(routeGraphic.getGeometry(), 15);

                }

            }

Hope it helps.

Now I only have to find out why my polyline is black instead of orange and why the setExtent doesn't work. The  latter is probobly also related to the spatial reference.

[thilibu]

thnx a lot.. Here route means object from Route or another?

[ÅsaWegelius]

I just copied from a project I'm working on. The Route is a GPFeatureRecordSetLayer I get back from a service.

[ÅsaWegelius]

I try show in your code instead:

    MapView mMapView = null;

    // The basemap switching menu items.

    MenuItem mStreetsMenuItem = null;

    MenuItem mTopoMenuItem = null;

    MenuItem mGrayMenuItem = null;

    MenuItem mOceansMenuItem = null;

    // Create MapOptions for each type of basemap.

    final MapOptions mTopoBasemap = new MapOptions(MapOptions.MapType.TOPO);

    final MapOptions mStreetsBasemap = new MapOptions(MapOptions.MapType.STREETS);

    final MapOptions mGrayBasemap = new MapOptions(MapOptions.MapType.GRAY);

    final MapOptions mOceansBasemap = new MapOptions(MapOptions.MapType.OCEANS);

// Here is the field for saving the maps spatial reference

    private SpatialReference mapSpatialReference;

    ArcGISTiledMapServiceLayer tms = new ArcGISTiledMapServiceLayer("http://services.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer");

    // The current map extent, use to set the extent of the map after switching basemaps.

    Polygon mCurrentMapExtent = null;

    GraphicsLayer mLocationLayer;

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_gis2);

        // Retrieve the map and initial extent from XML layout

        mMapView = (MapView) findViewById(R.id.map);

        mLocationLayer = new GraphicsLayer();

        mMapView.addLayer(tms);

        // Set the Esri logo to be visible, and enable map to wrap around date line.

        mMapView.setEsriLogoVisible(false);

        mMapView.enableWrapAround(true);

        // Set a listener for map status changes; this will be called when switching basemaps.

        mMapView.setOnStatusChangedListener(new OnStatusChangedListener() {

            private static final long serialVersionUID = 1L;

            @Override

            public void onStatusChanged(Object source, STATUS status) {

                // Set the map extent once the map has been initialized, and the basemap is added

                // or changed; this will be indicated by the layer initialization of the basemap layer. As there is only

                // a single layer, there is no need to check the source object.

                if ((source == mMapView) && (status == STATUS.INITIALIZED)) {

                    boolean mIsMapLoaded = true;

                    mapSpatialReference = mMapView.getSpatialReference();

                    // if you need to check the maps spatial reference before you draw you do like this to ensure

                    //you don't draw before the map is initialized

                    writePolyline();

                }

            }

        });

    }

    public void writePolyline(){

        SimpleLineSymbol lineSymbol = new SimpleLineSymbol(Color.GREEN, 3, SimpleLineSymbol.STYLE.DASH);

        Polyline lineGeometry = new Polyline();

        lineGeometry.startPath(-302557, 7570663);

        lineGeometry.lineTo(-302959, 7570868);

        lineGeometry.lineTo(-303042, 7571220);

        lineGeometry.lineTo(-302700, 7571803);

        lineGeometry.lineTo(-304043, 7576654);

        lineGeometry.lineTo(-300544, 7585289);

        lineGeometry.lineTo(-294365, 7592435);

        lineGeometry.lineTo(-290122, 7594445);

        lineGeometry.lineTo(-285283, 7595488);

        GeometryEngine engine = new GeometryEngine();

        Graphic lineGraphic = new Graphic(lineGeometry, lineSymbol);

// here I get the maps corners to show that the polyline is way outside its boundaries so you either use points inside

// or finds the spatial reference from the map you got the points from and use an engine as I do below to projet it to the correct one

        Polygon mapExtent = mMapView.getExtent();

        System.out.println("mapViews extent " + mapExtent.toString() + " no of points " + mapExtent.getPointCount());

        for(int i = 0; i < mapExtent.getPointCount(); i++){

            System.out.println("point " + i +"  " + mapExtent.getPoint(i).getX() +  " x " + mapExtent.getPoint(i).getY() + " y ");

        }

        //PUT_YOUR POLYLINES SPATIAL REFERENCE WHERE IT IS SpatialReference.create(4326) NOW

       engine.project(lineGeometry, SpatialReference.create(4326), mapSpatialReference);

        mLocationLayer.addGraphic(lineGraphic);

    }

[thilibu]

thnk u very much..