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ListSourceDataAdapter Class

The data adapter that provides the means to bind the Map control to data.

Namespace: DevExpress.XtraMap

Assembly: DevExpress.XtraMap.v22.2.dll

NuGet Package: DevExpress.Win.Map

Declaration

[ListSourceDataAdapter.ListSourceBindingProperties]
public class ListSourceDataAdapter :
    DataSourceAdapterBase,
    IListSourceDataAdapter,
    IDataSourceDataAdapter,
    IDataAdapter,
    IDisposable

Examples

Display Custom Elements on a Map

View Example

This example illustrates how to bind a Map control to data. This data is stored in an external XML file, which contains information about wrecked ships, including ship coordinates.

In this example, the map control automatically generates ship images based on data from the data source, along with a description for each image in a tooltip.

ListSourceDataAdapterExample

To accomplish this task, do the following:

  1. Create a ListSourceDataAdapter object and assign it to the VectorItemsLayer.Data property.
  2. Create a data source (in this example, this is a data table object generated by the LoadData method) and assign it to the DataSourceAdapterBase.DataSource property of the data adapter.
  3. To define names of data fields that contain information about latitude and longitude of vector items, specify appropriate values for MapItemMappingInfo.Latitude and MapItemMappingInfo.Longitude properties of the object, returned by the ListSourceDataAdapter.Mappings property.
  4. After that, define the names of other data fields that provide additional information for generated vector items. Note that these data fields values are accessible via attributes - and so you should specify attribute mapping via the DataSourceAdapterBase.AttributeMappings object.

Also, this sample illustrates how to customize tooltips using the MapItemsLayerBase.ToolTipPattern property.

Note

If you run this sample as is, you will get a warning message saying that the specified Bing Maps key is invalid. To learn how to avoid this error, refer to the How to: Get a Bing Maps Key tutorial.

// In the Form's constructor.
object data = LoadData(@"..\..\Data\Ships.xml");

// Create a vector layer.
map.Layers.Add(new VectorItemsLayer() {
    Data = CreateAdapter(data),
    ToolTipPattern = "<b>{Name} ({Year})</b> \r\n{Description}",
    ItemImageIndex = 0
});


// Creates an adapter for the map's vector layer.
private IMapDataAdapter CreateAdapter(object source) {
    ListSourceDataAdapter adapter = new ListSourceDataAdapter();

    adapter.DataSource = source;

    adapter.Mappings.Latitude = "Latitude";
    adapter.Mappings.Longitude = "Longitude";

    adapter.AttributeMappings.Add(new MapItemAttributeMapping() { Member = "Name", Name = "Name" });
    adapter.AttributeMappings.Add(new MapItemAttributeMapping() { Member = "Year", Name = "Year" });
    adapter.AttributeMappings.Add(new MapItemAttributeMapping() { Member = "Description", Name = "Description" });

    return adapter;
}

// Loads data from a XML file.
private List<ShipwreckData> LoadData(string path) {
    return XDocument.Load(path).Element("Ships").Elements("Ship")
        .Select(e => new ShipwreckData(
            year: Convert.ToInt32(e.Element("Year").Value, CultureInfo.InvariantCulture),
            name: e.Element("Name").Value,
            description: e.Element("Description").Value,
            latitude: Convert.ToDouble(e.Element("Latitude").Value, CultureInfo.InvariantCulture),
            longitude: Convert.ToDouble(e.Element("Longitude").Value, CultureInfo.InvariantCulture)
        ))
        .ToList();
}

public class ShipwreckData {
    public int Year { get; }
    public string Name { get; }
    public string Description { get; }
    public double Latitude { get; }
    public double Longitude { get; }

    public ShipwreckData(int year, string name, string description, double latitude, double longitude) {
        this.Year = year;
        this.Name = name;
        this.Description = description;
        this.Latitude = latitude;
        this.Longitude = longitude;
    }
}

Create Polylines From a Collection of Points

The following example shows how to create map polylines based on a collection of coordinates, and configure the polyline color and thickness.

Map polylines

Follow the steps below to create a vector layer with polylines:

  1. Create a VectorItemsLayer object and add it to the map’s Layers collection.

  2. Create a ListSourceDataAdapter object and assign it to the vector layer’s Data property.

  3. Specify the adapter’s DataSource. The example below uses a list of objects that store information about lines, such as coordinate points.

  4. Set the adapter’s DefaultMapItemType property to MapItemType.Polyline to create polylines based on the data that the adapter loads.

  5. Add a MapPolylinePointCollectionMapping object to the adapter’s PropertyMappings. Specify the following mapping properties to define source fields from which the adapter should obtain polyline point data:

    • PointSourceMember – Specifies the data member that stores polylines points.
    • XCoordinateMember – Specifies the point source data member that contains x-coordinates of points (longitudes for geo points).
    • YCoordinateMember – Specifies the point source data member that contains y-coordinates of points (latitudes for geo points).
  6. To customize polyline appearance settings, use mappings that correspond to map item properties. For example, add the following mappings to the adapter’s PropertyMappings collection to specify the MapItem.Stroke and MapItem.StrokeWidth properties:

    You can use a mapping’s DefaultValue property to explicitly specify a map item property value (for example, MapItem.Stroke), or you can use the mapping’s Member property to map the property to a source data member.

  7. Call the MapControl.ZoomToFitLayerItems() method in the vector layer’s DataLoaded event handler to specify the map viewport boundaries so that they include all polylines.

The code below creates two polylines:

using DevExpress.XtraMap;
using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;

namespace CreateMapLines {
    public partial class Form1 : Form {
        public Form1() {
            InitializeComponent();
            // Create a background image layer and add it to the map.
            ImageLayer imageLayer = new ImageLayer();
            imageLayer.DataProvider = new BingMapDataProvider {
                BingKey = "Insert your Bing Maps key here.",
                Kind = BingMapKind.RoadGray
            };
            mapControl1.Layers.Add(imageLayer);

            // Create a vector layer and add it to the map.
            VectorItemsLayer vectorLayer = new VectorItemsLayer();
            mapControl1.Layers.Add(vectorLayer);

            // Create a ListSourceDataAdapter.
            // Specify its data source.
            // Configure mappings.
            // Assign the adapter to the vector layer.
            ListSourceDataAdapter adapter = new ListSourceDataAdapter();
            adapter.DataSource = GetLines();
            adapter.DefaultMapItemType = MapItemType.Polyline;
            adapter.PropertyMappings.Add(new MapPolylinePointCollectionMapping {
                XCoordinateMember = "Longitude", 
                PointSourceMember = "PointSource", 
                YCoordinateMember= "Latitude"
            });
            adapter.PropertyMappings.Add(new MapItemStrokeMapping { Member = "Color" });
            adapter.PropertyMappings.Add(new MapItemStrokeWidthMapping { DefaultValue = 4 });
            vectorLayer.Data = adapter;
            vectorLayer.DataLoaded += OnVectorLayerDataLoaded;
        }

        private void OnVectorLayerDataLoaded(object sender, DataLoadedEventArgs e) {
            // Zooms the map to fit all created lines.
            mapControl1.ZoomToFitLayerItems();
        }
        public List<Line> GetLines() {
            List<Line> lines = new List<Line>();

            Line line1 = new Line();
            line1.PointSource.Add(new Coordinate(-5.93107, -35.112723));
            line1.PointSource.Add(new Coordinate(-10.13507, -25.15696));
            line1.PointSource.Add(new Coordinate(-5.183714, -8.911391));
            line1.PointSource.Add(new Coordinate(4.253438, 5.47072));
            line1.Color = Color.Green;
            lines.Add(line1);

            Line line2 = new Line();
            line2.PointSource.Add(new Coordinate(1, 0.5));
            line2.PointSource.Add(new Coordinate(-25, -15));
            line2.PointSource.Add(new Coordinate(-15, -25));
            line2.PointSource.Add(new Coordinate(-22.1531, -41.45984));
            line2.Color = Color.Red;
            lines.Add(line2);

            return lines;
        }
    }
    public struct Coordinate {
        public double Latitude { get; }
        public double Longitude { get; }
        public Coordinate(double lat, double lon) {
            Latitude = lat;
            Longitude = lon;
        }
    }
    public class Line {
        public Color Color { get; set; }
        public List<Coordinate> PointSource { get; } = new List<Coordinate>();
    }
}

Create Polygons From a Collection of Points

The following example shows how to create map polygons based on a collection of coordinates, and configure the polygon stroke and fill colors.

Map polygons

Follow the steps below to create a vector layer with polygons:

  1. Create a VectorItemsLayer object and add it to the map’s Layers collection.

  2. Create a ListSourceDataAdapter object and assign it to the vector layer’s Data property.

  3. Specify the adapter’s DataSource. The example below uses a list of objects that store information about polygons, such as coordinate points.

  4. Set the adapter’s DefaultMapItemType property to MapItemType.Polygon to create polygon based on the data that the adapter loads.

  5. Add a MapPolygonPointCollectionMapping object to the adapter’s PropertyMappings. Specify the following mapping properties to define source fields from which the adapter should obtain polygon point data:

    • PointSourceMember – Specifies the data member that stores polygon points.
    • XCoordinateMember – Specifies the point source data member that contains x-coordinates of points (longitudes for geo points).
    • YCoordinateMember – Specifies the point source data member that contains y-coordinates of points (latitudes for geo points).
  6. To customize polygon appearance settings, use mappings that correspond to map item properties. For example, add the following mappings to the adapter’s PropertyMappings collection to specify the MapItem.Stroke, MapItem.Fill, and MapItem.StrokeWidth properties:

    You can use a mapping’s DefaultValue property to explicitly specify a map item property value (for example, MapItem.Stroke), or you can use the mapping’s Member property to map the property to a source data member.

  7. Call the MapControl.ZoomToFitLayerItems() method in the vector layer’s DataLoaded event handler to specify the map viewport boundaries so that they include all polygons.

The code below creates two polygons:

using DevExpress.XtraMap;
using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;

namespace CreateMapPolygons {
    public partial class Form1 : Form {
        public Form1() {
            InitializeComponent();
            // Create a background image layer and add it to the map.
            ImageLayer imageLayer = new ImageLayer();
            imageLayer.DataProvider = new BingMapDataProvider {
                BingKey = "Insert your Bing Maps key here.",
                Kind = BingMapKind.RoadGray
            };
            mapControl1.Layers.Add(imageLayer);

            // Create a vector layer and add it to the map.
            VectorItemsLayer vectorLayer = new VectorItemsLayer();
            mapControl1.Layers.Add(vectorLayer);

            // Create a ListSourceDataAdapter.
            // Specify its data source.
            // Configure mappings.
            // Assign the adapter to the vector layer.
            ListSourceDataAdapter adapter = new ListSourceDataAdapter();
            adapter.DataSource = GetPolygons();
            adapter.DefaultMapItemType = MapItemType.Polygon;
            adapter.PropertyMappings.Add(new MapPolygonPointCollectionMapping {
                XCoordinateMember = "Longitude",
                PointSourceMember = "PointSource",
                YCoordinateMember = "Latitude"
            });
            adapter.PropertyMappings.Add(new MapItemStrokeMapping { Member = "StrokeColor" });
            adapter.PropertyMappings.Add(new MapItemFillMapping { Member = "FillColor" });
            adapter.PropertyMappings.Add(new MapItemStrokeWidthMapping { DefaultValue = 4 });
            vectorLayer.Data = adapter;
            vectorLayer.DataLoaded += OnVectorLayerDataLoaded;
        }

        private void OnVectorLayerDataLoaded(object sender, DataLoadedEventArgs e) {
            // Zooms the map so that it displays all created polygons.
            mapControl1.ZoomToFitLayerItems(paddingFactor: 0.5);
        }
        public List<Polygon> GetPolygons() {
            List<Polygon> polygons = new List<Polygon>();

            Polygon polygon1 = new Polygon();
            polygon1.PointSource.Add(new Coordinate(-3.5, -30.3));
            polygon1.PointSource.Add(new Coordinate(-2.4, -9.8));
            polygon1.PointSource.Add(new Coordinate(-9.0, -19.4));
            polygon1.PointSource.Add(new Coordinate(-12.9, -31.1));
            polygon1.StrokeColor = Color.Green;
            polygon1.FillColor = Color.White;
            polygons.Add(polygon1);

            Polygon polygon2 = new Polygon();
            polygon2.PointSource.Add(new Coordinate(-13.5, -9.6));
            polygon2.PointSource.Add(new Coordinate(-17.5, 0.3));
            polygon2.PointSource.Add(new Coordinate(-21.8, -7.8));
            polygon2.StrokeColor = Color.Red;
            polygon2.FillColor = Color.DarkGray;
            polygons.Add(polygon2);

            return polygons;
        }
    }
    public struct Coordinate {
        public double Latitude { get; }
        public double Longitude { get; }
        public Coordinate(double lat, double lon) {
            Latitude = lat;
            Longitude = lon;
        }
    }
    public class Polygon {
        public Color StrokeColor { get; set; }
        public Color FillColor { get; set; }
        public List<Coordinate> PointSource { get; } = new List<Coordinate>();
    }
}

Implements

See Also