Layers

• Jan 15, 2024
• 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

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:

Form1.cs

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

Form1.vb

mapControl1.Layers.Add(New ImageLayer() With {
            .DataProvider = New BingMapDataProvider() With {
                .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

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:

View Example

C#

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;
  }
}

VB.NET

Public Partial Class Form1
    Inherits Form

    Const filename As String = "../../Data/Countries.shp"

    Private ReadOnly Property MapLayer As VectorItemsLayer
        Get
            Return CType(mapControl1.Layers("MapLayer"), VectorItemsLayer)
        End Get
    End Property

    Public Sub New()
        InitializeComponent()
        MapLayer.Data = CreateData()
    End Sub

    Private Function CreateData() As MapDataAdapterBase
        Dim baseUri As Uri = New Uri(System.Reflection.Assembly.GetEntryAssembly().Location)
        Dim adapter As ShapefileDataAdapter = New ShapefileDataAdapter() With {
            .FileUri = New Uri(baseUri, filename)
        }
        Return adapter
    End Function
End Class

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

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:

Form1.cs

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;
        }      
    }
}

Form1.vb

Imports DevExpress.XtraMap
Imports System.Windows.Forms

Namespace ConnectBingSearchProvider
    Partial Public Class Form1
        Inherits Form

        Private Const bingKey As String = "YOUR BING KEY HERE"

        Private ReadOnly Property SearchLayer() As InformationLayer
            Get
                Return CType(mapControl1.Layers("SearchLayer"), InformationLayer)
            End Get
        End Property

        Public Sub New()
            InitializeComponent()

            Dim searchProvider As New BingSearchDataProvider() With {.BingKey = bingKey}

            searchProvider.SearchOptions.ResultsCount = 5

            SearchLayer.DataProvider = searchProvider
        End Sub
    End Class
End Namespace

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.