KmlFileDataAdapter Class

A data adapter that loads data from KML and KMZ files, and displays it on vector layers.

Namespace: DevExpress.XtraMap

Assembly: DevExpress.XtraMap.v23.2.dll

NuGet Package: DevExpress.Win.Map

Declaration

C#

public class KmlFileDataAdapter :
    FileDataAdapterBase

VB.NET

Public Class KmlFileDataAdapter
    Inherits FileDataAdapterBase

Remarks

A .KML file uses the Keyhole Markup Language format to store geographic data such as locations, lines, polygons, images, text, and etc. KML files have a tag-based structure with nested elements (similar to XML standard). KML files can be distributed as KMZ files (zipped KML files with a .kmz extension).

The following table lists supported KML elements and corresponding map items:

KML element	Map item
Point	MapCustomElement
Polygon	MapPath
LinearRing	MapPolyline
LineString	MapPolyline
MultiGeometry	MapPath

Load KML/KMZ Data

The Map Control allows you to load data from KML/KMZ files and display it on a vector layer. You can also display vector data above an image tile map. For example, the image below shows a shape loaded from a KML file:

Perform the steps below to load vector data from a KML/KMZ file:

1. Create a KmlFileDataAdapter object.
2. Specify the path to a KML/KMZ file via the FileDataAdapterBase.FileUri property.
3. Assign the KmlFileDataAdapter to the VectorItemsLayer.Data property.

View Example

Form1.cs

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

namespace WinForms_MapControl_KmlFileDataAdapter {
    public partial class Form1 : Form {
        const string filePath = "../../kmlFile.kml";

        VectorItemsLayer KmlLayer { get { return (VectorItemsLayer)mapControl1.Layers["KmlLayer"]; } }

        public Form1() {
            InitializeComponent();
            Uri baseUri = new Uri(System.Reflection.Assembly.GetEntryAssembly().Location);
            KmlLayer.Data =  new KmlFileDataAdapter() {
                FileUri = new Uri(baseUri, filePath)
            };
        }
    }
}

Form1.vb

Imports DevExpress.XtraMap
Imports System
Imports System.Windows.Forms

Namespace WinForms_MapControl_KmlFileDataAdapter
    Partial Public Class Form1
        Inherits Form

        Private Const filePath As String = "../../kmlFile.kml"

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

        Public Sub New()
            InitializeComponent()
            Dim baseUri As New Uri(System.Reflection.Assembly.GetEntryAssembly().Location)
            KmlLayer.Data = New KmlFileDataAdapter() With {.FileUri = New Uri(baseUri, filePath)}
        End Sub
    End Class
End Namespace

Access and Customize Generated Items

Handle the FileDataAdapterBase.ItemsLoaded event to access a collection of generated vector items (see the ItemsLoadedEventArgs.Items property) and customize their appearance.

C#

using DevExpress.Utils.Design;
using DevExpress.Utils.Svg;
using DevExpress.XtraMap;
using System.Drawing;
using System.Windows.Forms;

readonly SvgImage svgImage = SvgImage.FromFile(GetRelativePath("Images\\map-pointer.svg"));

private void Form1_Load(object sender, EventArgs e) {
    VectorItemsLayer vectorLayer = new VectorItemsLayer();
    mapControl1.Layers.Add(vectorLayer);

    KmlFileDataAdapter dataAdapter = new KmlFileDataAdapter();
    dataAdapter.FileUri = new Uri(GetRelativePath("Data\\subway-entrances.kmz"), UriKind.RelativeOrAbsolute);
    vectorLayer.Data = dataAdapter;
    dataAdapter.ItemsLoaded += OnDataAdapterItemsLoaded;
}

private void OnDataAdapterItemsLoaded(object sender, ItemsLoadedEventArgs e) {  
    foreach (MapCustomElement item in e.Items) {
        item.ToolTipPattern = "{name}";
        item.Text = string.Empty;
        item.SvgImage = svgImage;
        item.SvgImageSize = new Size(24, 24);              
    }
}

VB.NET

Imports DevExpress.Utils.Design
Imports DevExpress.Utils.Svg
Imports DevExpress.XtraMap
Imports System.Drawing
Imports System.Windows.Forms

Private ReadOnly svgImage As SvgImage = SvgImage.FromFile(GetRelativePath("Images\map-pointer.svg"))

Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs)
    Dim vectorLayer As VectorItemsLayer = New VectorItemsLayer()
    mapControl1.Layers.Add(vectorLayer)

    Dim dataAdapter As KmlFileDataAdapter = New KmlFileDataAdapter()
    dataAdapter.FileUri = New Uri(GetRelativePath("Data\subway-entrances.kmz"), UriKind.RelativeOrAbsolute)
    vectorLayer.Data = dataAdapter
    dataAdapter.ItemsLoaded += OnDataAdapterItemsLoaded
End Sub

Private Sub OnDataAdapterItemsLoaded(ByVal sender As Object, ByVal e As ItemsLoadedEventArgs)
    For Each item As MapCustomElement In e.Items
        item.ToolTipPattern = "{name}"
        item.Text = String.Empty
        item.SvgImage = svgImage
        item.SvgImageSize = New Size(24, 24)
    Next
End Sub

You can also group items of the same type. To do this, initialize the MapDataAdapterBase.Clusterer property with a clusterer.

Implements

IMapDataAdapter

Inheritance

Object

MapDisposableObject

MapDataAdapterBase

CoordinateSystemDataAdapterBase

DevExpress.XtraMap.OuterDataAdapterBase

FileDataAdapterBase

KmlFileDataAdapter