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Layers

  • 6 minutes to read

The Map Control uses layers to visualize different types of information, such as raster or vector geographical tiles, geo images, vector shapes, or heatmap data. You can combine multiple layers of different types on the same map.

To add a layer to the map, add an appropriate layer object to the MapControl.Layers collection. The order of layer objects in the collection determines their Z-order. Since each additional layer is drawn over its preceding layer, the first layer is located behind all additional layers. To change the Z-order of a layer, use its LayerBase.ZIndex property.

To load data to a layer, assign a compatible data provider or adapter.

Also, you can show additional information on top of a map in semitransparent text boxes called overlays. For more information, refer to the following help topic: Overlays.

The following sections describe available layers.

#Image Layer

Image layers allow you to show raster and vector tiled maps, georeferenced map images from Web map services, and heatmaps. To show tiles, the Map Control uses a tile system that is similar to the Bing Maps tile system, and utilizes the spherical Mercator projection as default. Refer to the following topic for more information: Geographical Projections.

The following image shows a map with raster tiles from Bing Maps:

Run Demo

A map with tiles from Bing Maps (GrayRoad mode)

The ImageLayer class implements the image layer functionality. To load data to the layer, specify the ImageLayer.DataProvider property. For the list of available data providers, refer to the following section: Data Providers for Image Item Layers.

The following code creates an image layer, adds it to the map, and loads Bing Maps image tiles to the layer:

mapControl1.Layers.Add(new ImageLayer() {
    DataProvider = new BingMapDataProvider() {
        BingKey = "YOUR BING KEY",
        Kind = BingMapKind.Road
    }
});

For a step-by-step tutorial on how to create a map application with Bing Map tiles, refer to the following topic: Lesson 1 - Load Image Tiles to a Map.

#Data Providers for Image Layers

The following list contains data providers that allow you to supply image layers with data:

BingMapDataProvider
Allows you to obtain raster image tiles from the Bing Maps service.
OpenStreetMapDataProvider
Allows you to load raster image tiles from the OpenStreetMap service.
ImageTileDataProvider
Allows you to load tiles from in-memory sources.
MapboxDataProvider
Allows you to render tiles based on vector tile data from the Mapbox service.
MbTilesDataProvider
Loads vector tiles from an MbTiles database.
UriBasedVectorTileDataProvider
Loads map data from a set of PBF or MVT files.
HeatmapProvider
Allows you to visualize heatmap data over the map.
WmsDataProvider
Allows you to receive geographical data images from a WMS server.

#Vector Item Layer

Vector item layers are intended to display vector shapes (for example, pushpins, polygons, or lines). The Map Control can adapt vector shape data loaded from various sources.

The following image shows vector items (bubbles) on top of a geographical map:

Run Demo

Map that shows vector layer with bubbles

The VectorItemsLayer class implements the vector layer functionality. To load data to the layer, specify the VectorItemsLayer.Data property. For the list of available data adapters, refer to the following section: Data Adapters for Vector Item Layers.

The following example loads vector polygons from a shapefile:

A map with vector polygons

View Example

public partial class Form1 : Form {
  const string filename = "../../Data/Countries.shp";
  VectorItemsLayer MapLayer { get { return (VectorItemsLayer)mapControl1.Layers["MapLayer"]; } }

  public Form1() {
      InitializeComponent();
      MapLayer.Data = CreateData();
  }
  private MapDataAdapterBase CreateData() {
      Uri baseUri = new Uri(System.Reflection.Assembly.GetEntryAssembly().Location);
      // Create an adapter to load data from the shapefile.
      ShapefileDataAdapter adapter = new ShapefileDataAdapter() {
          FileUri = new Uri(baseUri, filename)
      };
      return adapter;
  }
}

For a step-by-step tutorial on how to load vector items from a shapefile, refer to the following topic: Lesson 2 - Load a Vector Cartesian Map.

#Data Adapters for Vector Item Layers

The following list contains data adapters that allow you to supply vector layers with data:

MapItemStorage
Stores vector items that you manually added to the map.
GeoJsonFileDataAdapter
Loads vector items from a GeoJSON file.
GpxFileDataAdapter
Loads vector items from a GPX file.
SqlGeometryDataAdapter
Loads data from an SQL geometry data source.
SqlGeometryItemStorage
Stores manually created SQL geometry vector items.
KmlFileDataAdapter
Loads vector items from a KML/KMZ file.
SvgFileDataAdapter
Loads vector items from an SVG file.
ShapefileDataAdapter
Loads vector items from a shapefile.
BubbleChartDataAdapter
Allows you to show bubble charts on the map.
PieChartDataAdapter
Allows you to show pie charts on the map.
ListSourceDataAdapter
Allows you to create items from lists or list sources.

#Information Layer

Information layers are used to show map vector items that the Map Control creates based on data obtained from Geographic Information System services (GIS services).

The following image shows traffic incident information loaded from the Bing Maps Traffic service:

Run Demo

This map shows traffic incidents.

The InformationLayer class implements the information layer functionality. To load data to the layer, specify the InformationLayer.DataProvider property. For the list of available data providers, refer to the following section: Data Providers for Information Layers.

The following example allows users to search locations. A search query adds pushpins at found locations:

A map with enabled search

using DevExpress.XtraMap;
using System.Windows.Forms;

namespace ConnectBingSearchProvider {
    public partial class Form1 : Form {
        const string bingKey = "YOUR BING KEY HERE";

        InformationLayer SearchLayer { 
            get {
                return (InformationLayer)mapControl1.Layers["SearchLayer"];
            }
        }

        public Form1() {
            InitializeComponent();

            BingSearchDataProvider searchProvider = new BingSearchDataProvider() { 
                BingKey = bingKey 
            };

            searchProvider.SearchOptions.ResultsCount = 5;

            SearchLayer.DataProvider = searchProvider;
        }      
    }
}

#Data Providers for Information Layers

The following list contains data providers that allow you to supply information layers with GIS data:

BingElevationDataProvider
Obtains elevation information by geo coordinates.
BingGeocodeDataProvider
Gets geographical coordinates for a location by its address.
BingRouteDataProvider
Builds a route by waypoints with different optimization parameters.
BingRouteIsochroneDataProvider
Calculates an isochrone that shows an area reachable from a specific location.
BingSearchDataProvider
Allows you to use the Bing Search service to search for locations by the specified address or keyword.
BingTrafficIncidentDataProvider
Receives information about traffic incidents and displays incident icons on the map.
OsmGeocodeDataProvider
Gets geographical coordinates for a location by its address.
OsmSearchDataProvider
Allows you to use the Open Street Map to search for locations by the specified address or keyword.
See Also