CustomData.md

Displaying Custom Data

There are three different types of objects used to display data on the map control:

• Marker - for displaying single-point objects;
• Track - for displaying multiline objects (set of connected points);
• Polygon - for displaying area objects.

Map control has correspoding properties to add these objects, i.e.:

public ICollection<Marker> Markers { get; }

public ICollection<Track> Tracks { get; }

public ICollection<Polygon> Polygons { get; }

Markers

By default, markers are drawn as filled circles with specified diameter in pixels, and with label. To add new marker to the map:

// Create marker's location point
var point = new GeoPoint(44.0, 56.3333);

// Create marker instance: specify location on the map, drawing style, and label
var marker = new Marker(point, MarkerStyle.Default, "Some label");

// Add marker to the map
mapControl.Markers.Add(marker);

You can customize the marker drawing style by:

// Set marker diameter (3), fill brush (red), outline pen (blue), label brush (black), label font (default system), label formatting (generic default)
var style = new MarkerStyle(3, Brushes.Red, Pens.Blue, Brushes.Black, SystemFonts.DefaultFont, StringFormat.GenericDefault);

// Create marker with custom style
var marker = new Marker(point, style, "Some label");

Also you can override drawing the marker with handling DrawMarker event. For example, to draw a 24x24 image instead of marker circle, do the following:

// Subscribe to DrawMarker event
mapControl.DrawMarker += new EventHandler<DrawMarkerEventArgs>(mapControl_DrawMarker);

// Create marker image
Image imageMarker = Image.FromFile("Path/to/image.png");

// Event handler
private void mapControl_DrawMarker(object sender, DrawMarkerEventArgs e)
{
    // Important: set flag to override drawing
    e.Handled = true;

    // Draw image
    e.Graphics.DrawImage(imageMarker, new Rectangle((int)e.Point.X - 12, (int)e.Point.Y - 24, 24, 24));
    
    // And label
    e.Graphics.DrawString(e.Marker.Label, SystemFonts.DefaultFont, Brushes.Red, new PointF(e.Point.X, e.Point.Y + 5), new StringFormat() { Alignment = StringAlignment.Center, LineAlignment = StringAlignment.Near });
}

You can use different images for markers. To distinguish markers, use Data property of the Marker class. It can be any object you want, for example, marker unique identifier.

Tracks

To add a track to the map, do the following:

// Initializing collection of points,
// filling points with data omitted
var points = new List<GeoPoint>();

// Creating a track with default style
var track = new Track(TrackStyle.Default);

// Add points to the track
track.AddRange(points);

// Add track to the map
mapControl.Tracks.Add(track);

Track style is also customizable:

// Define custom track style
var style = new TrackStyle(new Pen(Color.Blue) { DashStyle = System.Drawing.Drawing2D.DashStyle.Dash });

// Assign style to the track
var track = new Track(style);

Polygons

Working with polygons is similar to deal with tracks. To create a new area object to the map, do something like:

// Default-styled polygon
var polygon = new Polygon(PolygonStyle.Default);

// Add points
polygon.AddRange(points);

// Add it to the map
mapControl.Polygons.Add(polygon);

Again, if you need to customize style of the polygon:

// Brush to fill polygon area
var brush = Brushes.Gray;

// Pen to draw polygon outline
var pen = Pens.Black;

// Custom style
var style = new PolygonStyle(brush, pen);

// Make styled polygon
var polygon = new Polygon(style);