.NET MAUI Map Shapes Styling

The Map ShapefileLayer exposes ShapeStyle property which helps you to style the shapes, as well as the selected shapes using the SelectedShapeStyle property. A conditional styling is applied using the ShapeStyleSelector property.

Shapes Styles

ShapeStyle and SelectedShapeStyle properties of type( MapShapeStyle) provides the following styling options for the shapes:

• StrokeWidth
• StrokeColor
• FillColor

The snippet below shows how ShapeStyle property can be applied:

<telerik:RadMap x:Name="map">
    <telerik:RadMap.Layers>
        <telerik:ShapefileLayer>
            <telerik:ShapefileLayer.Reader>
                <telerik:MapShapeReader x:Name="reader"/>
            </telerik:ShapefileLayer.Reader>
            <telerik:ShapefileLayer.ShapeStyle>
                <telerik:MapShapeStyle FillColor="White"
                                          StrokeColor="#7BD5FB"/>
            </telerik:ShapefileLayer.ShapeStyle>
        </telerik:ShapefileLayer>
    </telerik:RadMap.Layers>
</telerik:RadMap>

Here is the result:

Define the Source and the DataSource of the MapShapeReader to a .shp and .dbf files, respectively:

var assembly = this.GetType().Assembly;
var source = MapSource.FromResource("SDKBrowserMaui.Examples.MapControl.world.shp", assembly);
this.reader.Source = source;

Style Selector for Shapes

Using the ShapeStyleSelector property of the ShapefileLayer you can implement conditional styling.

The example below shows how to apply different styles to shapes according to certain property value of each shape.

1. First, create the selector class which inherit from MapShapeStyleSelector:

public class PopulationShapeStyleSelector : MapShapeStyleSelector
{
    public MapShapeStyle HighPopulationShapeStyle { get; set; }
    public MapShapeStyle MediumPopulationShapeStyle { get; set; }
    public MapShapeStyle LowPopulationShapeStyle { get; set; }

    public override MapShapeStyle SelectStyle(object shape, BindableObject container)
    {
        var attributesShape = shape as IShape;
        if (attributesShape != null)
        {
            var populationText = attributesShape.GetAttribute("POP_CNTRY").ToString();
            int population;
            if (int.TryParse(populationText, out population))
            {
                if (population > 20000000)
                {
                    return this.HighPopulationShapeStyle;
                }
                else if (population < 1000000)
                {
                    return this.LowPopulationShapeStyle;
                }

                return this.MediumPopulationShapeStyle;
            }
        }

        return null;
    }
}

2. Define the selector with the Styles as a resource inside a ResourceDictionary:

<ResourceDictionary>
    <local:PopulationShapeStyleSelector x:Key="PopulationShapeStyleSelector">
        <local:PopulationShapeStyleSelector.HighPopulationShapeStyle>
            <telerik:MapShapeStyle FillColor="DarkGreen" StrokeColor="LightGray"/>
        </local:PopulationShapeStyleSelector.HighPopulationShapeStyle>
        <local:PopulationShapeStyleSelector.MediumPopulationShapeStyle>
            <telerik:MapShapeStyle FillColor="Green" StrokeColor="LightGray"/>
        </local:PopulationShapeStyleSelector.MediumPopulationShapeStyle>
        <local:PopulationShapeStyleSelector.LowPopulationShapeStyle>
            <telerik:MapShapeStyle FillColor="LightGreen" StrokeColor="LightGray"/>
        </local:PopulationShapeStyleSelector.LowPopulationShapeStyle>
    </local:PopulationShapeStyleSelector>
</ResourceDictionary>

3. Add the definition of the RadMap control with the PopulationShapeStyleSelector applied;

<telerik:RadMap x:Name="map">
    <telerik:RadMap.Layers>
        <telerik:ShapefileLayer ShapeStyleSelector="{StaticResource PopulationShapeStyleSelector}">
            <telerik:ShapefileLayer.Reader>
                <telerik:MapShapeReader x:Name="reader"/>
            </telerik:ShapefileLayer.Reader>
        </telerik:ShapefileLayer>
    </telerik:RadMap.Layers>
</telerik:RadMap>

4. Add the namespace:

xmlns:telerik="http://schemas.telerik.com/2022/xaml/maui"

Check the result in the screenshot below:

See Also

• ShapefileLayer
• Labels Styling