windowsforms-devexpress-dot-xtramap-473f9105.md
Allows you to specify data members used to create map polygons.
Namespace : DevExpress.XtraMap
Assembly : DevExpress.XtraMap.v25.2.dll
NuGet Package : DevExpress.Win.Map
public class MapPolygonPointCollectionMapping :
MapMultipointItemMappingBase<MapPolygon>
Public Class MapPolygonPointCollectionMapping
Inherits MapMultipointItemMappingBase(Of MapPolygon)
Use MapPolygonPointCollectionMapping to specify mappings that ListSourceDataAdapter uses to generate map polygons from collections of coordinate points.
The following properties allow you to specify data source fields that store polygon data:
PointSourceMemberSpecifies the data member that stores polygon points.XCoordinateMemberSpecifies the point source data member that contains x-coordinates of points (latitudes for geo points).YCoordinateMemberSpecifies the point source data member that contains y-coordinates of points (latitudes for geo points).
The following example shows how to create map polygons based on a collection of coordinates, and configure the polygon stroke and fill colors.
Follow the steps below to create a vector layer with polygons:
Create a VectorItemsLayer object and add it to the map’s Layers collection.
Create a ListSourceDataAdapter object and assign it to the vector layer’s Data property.
Specify the adapter’s DataSource. The example below uses a list of objects that store information about polygons, such as coordinate points.
Set the adapter’s DefaultMapItemType property to MapItemType.Polygon to create polygon based on the data that the adapter loads.
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:
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:
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>();
}
}
Imports DevExpress.XtraMap
Imports System.Collections.Generic
Imports System.Drawing
Imports System.Windows.Forms
Namespace CreateMapPolygons
Public Partial Class Form1
Inherits Form
Public Sub New()
InitializeComponent()
' Create a background image layer and add it to the map.
Dim imageLayer As ImageLayer = New ImageLayer()
imageLayer.DataProvider = New BingMapDataProvider With {
.BingKey = "Insert your Bing Maps key here.",
.Kind = BingMapKind.RoadGray
}
mapControl1.Layers.Add(imageLayer)
' Create a vector layer and add it to the map.
Dim vectorLayer As VectorItemsLayer = New VectorItemsLayer()
mapControl1.Layers.Add(vectorLayer)
' Create a ListSourceDataAdapter.
' Specify its data source.
' Configure mappings.
' Assign the adapter to the vector layer.
Dim adapter As ListSourceDataAdapter = New ListSourceDataAdapter()
adapter.DataSource = GetPolygons()
adapter.DefaultMapItemType = MapItemType.Polygon
adapter.PropertyMappings.Add(New MapPolygonPointCollectionMapping With {
.XCoordinateMember = "Longitude",
.PointSourceMember = "PointSource",
.YCoordinateMember = "Latitude"
})
adapter.PropertyMappings.Add(New MapItemStrokeMapping With {
.Member = "StrokeColor"
})
adapter.PropertyMappings.Add(New MapItemFillMapping With {
.Member = "FillColor"
})
adapter.PropertyMappings.Add(New MapItemStrokeWidthMapping With {
.DefaultValue = 4
})
vectorLayer.Data = adapter
vectorLayer.DataLoaded += AddressOf OnVectorLayerDataLoaded
End Sub
Private Sub OnVectorLayerDataLoaded(ByVal sender As Object, ByVal e As DataLoadedEventArgs)
' Zooms the map so that it displays all created polygons.
mapControl1.ZoomToFitLayerItems(paddingFactor:=0.5)
End Sub
Public Function GetPolygons() As List(Of Polygon)
Dim polygons As List(Of Polygon) = New List(Of Polygon)()
Dim polygon1 As Polygon = 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)
Dim polygon2 As Polygon = 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
End Function
End Class
Public Structure Coordinate
Public ReadOnly Property Latitude As Double
Public ReadOnly Property Longitude As Double
Public Sub New(ByVal lat As Double, ByVal lon As Double)
Latitude = lat
Longitude = lon
End Sub
End Structure
Public Class Polygon
Public Property StrokeColor As Color
Public Property FillColor As Color
Public ReadOnly Property PointSource As List(Of Coordinate) = New List(Of Coordinate)()
End Class
End Namespace
Object DevExpress.XtraMap.Native.MapItemMappingBase MapItemPropertyMappingBase DevExpress.XtraMap.MapItemPropertyMappingBase<MapPolygon> MapMultipointItemMappingBase<MapPolygon> MapPolygonPointCollectionMapping
See Also