MapControl.Legends Property

Provides access to a collection of legends that are displayed within the Map control.

Namespace: DevExpress.XtraMap

Assembly: DevExpress.XtraMap.v18.2.dll

Declaration

C#

public LegendCollection Legends { get; }

VB.NET

Public ReadOnly Property Legends As LegendCollection

Property Value

Type	Description
LegendCollection	A LegendCollection object.

Example

This example demonstrates how to paint each map contour in a specific color. To accomplish this, it is necessary to create a colorizer (choropleth or graph) and assign it to the VectorItemsLayer.Colorizer property.

For this colorizer, it is necessary to create a ShapeAttributeValueProvider object, specify the name of the shape attribute that contains a value to be colorized to its ShapeAttributeValueProvider.AttributeName property, and assign this value provider to the ChoroplethColorizer.ValueProvider property.

Then, split the entire data into ranges and add the required range stops to the DoubleCollection returned by the ChoroplethColorizer.RangeStops property.

Finally, add the desired set of colors to the GenericColorizerItemCollection<T> that is accessed from the ChoroplethColorizer.ColorItems property. The colorizer automatically associates each color with the specified data ranges.

Note

• If you wish to display information on what each color means, create a Color Scale legend. To do this, create a ColorScaleLegend object and add it to the MapControl.Legends collection. In this legend, set its ItemsLayerLegend.Layer property to the previously created layer object and adjust other legend properties as required.
• If you wish copy the shape file to your project, you should also copy the Countries.dbf file.

Note

A complete sample project is available at https://github.com/DevExpress-Examples/how-to-colorize-map-contours-loaded-from-shapefiles-using-the-choropleth-colorizer-e4691

Form1.cs

    // Create colorizer for the MapLayer.
    MapLayer.Colorizer = CreateColorizer();
private MapColorizer CreateColorizer() {
    // Create a Choropleth colorizer
    ChoroplethColorizer colorizer = new ChoroplethColorizer();

    // Specify colors for the colorizer.
    colorizer.ColorItems.AddRange(new ColorizerColorItem[] {
        new ColorizerColorItem(Color.FromArgb(0x5F, 0x8B, 0x95)), 
        new ColorizerColorItem(Color.FromArgb(0x79, 0x96, 0x89)),
        new ColorizerColorItem(Color.FromArgb(0xA2, 0xA8, 0x75)), 
        new ColorizerColorItem(Color.FromArgb(0xCE, 0xBB, 0x5F)),
        new ColorizerColorItem(Color.FromArgb(0xF2, 0xCB, 0x4E)),
        new ColorizerColorItem(Color.FromArgb(0xF1, 0xC1, 0x49)), 
        new ColorizerColorItem(Color.FromArgb(0xE5, 0xA8, 0x4D)),
        new ColorizerColorItem(Color.FromArgb(0xD6, 0x86, 0x4E)),
        new ColorizerColorItem(Color.FromArgb(0xC5, 0x64, 0x50)), 
        new ColorizerColorItem(Color.FromArgb(0xBA, 0x4D, 0x51))
    });

    // Specify range stops for the colorizer.
    colorizer.RangeStops.AddRange(new double[] { 0, 3000, 10000, 18000, 28000, 
        44000, 82000, 185000, 1000000, 2500000, 15000000 });

    // Specify the attribute that provides data values for the colorizer.
    colorizer.ValueProvider = new ShapeAttributeValueProvider() { AttributeName = "GDP_MD_EST" };

    return colorizer;
}

Form1.vb

    ' Create colorizer for the MapLayer.
    MapLayer.Colorizer = CreateColorizer()
Private Function CreateColorizer() As MapColorizer
    ' Create a Choropleth colorizer
    Dim colorizer As New ChoroplethColorizer()

    ' Specify colors for the colorizer.
    colorizer.ColorItems.AddRange(New ColorizerColorItem() { _
        New ColorizerColorItem(Color.FromArgb(&H5F, &H8B, &H95)), _
        New ColorizerColorItem(Color.FromArgb(&H79, &H96, &H89)), _
        New ColorizerColorItem(Color.FromArgb(&HA2, &HA8, &H75)), _
        New ColorizerColorItem(Color.FromArgb(&HCE, &HBB, &H5F)), _
        New ColorizerColorItem(Color.FromArgb(&HF2, &HCB, &H4E)), _
        New ColorizerColorItem(Color.FromArgb(&HF1, &HC1, &H49)), _
        New ColorizerColorItem(Color.FromArgb(&HE5, &HA8, &H4D)), _
        New ColorizerColorItem(Color.FromArgb(&HD6, &H86, &H4E)), _
        New ColorizerColorItem(Color.FromArgb(&HC5, &H64, &H50)), _
        New ColorizerColorItem(Color.FromArgb(&HBA, &H4D, &H51)) _
    })

    ' Specify range stops for the colorizer.
    colorizer.RangeStops.AddRange(New Double() { 0, 3000, 10000, 18000, 28000, 44000, 82000, 185000, 1000000, 2500000, 15000000 })

    ' Specify the attribute that provides data values for the colorizer.
    colorizer.ValueProvider = New ShapeAttributeValueProvider() With {.AttributeName = "GDP_MD_EST"}

    Return colorizer
End Function