CustomScale Class

Represents the scale that defines custom distribution of colors in the color range.

Namespace: DevExpress.DashboardCommon

Assembly: DevExpress.Dashboard.v19.2.Core.dll

Declaration

C#

public class CustomScale :
    MapScale

VB.NET

Public Class CustomScale
    Inherits MapScale

Remarks

The CustomScale.RangeStops property allows you to specify endpoints for color ranges in the custom palette. Use the CustomPalette.Colors property to specify colors used in the custom palette.

Example

The following example demonstrates how to customize a palette of the Choropleth map.

In this example, a set of custom colors is used to color map shapes depending on the provided values. Absolute values are used to specify endpoints for color ranges.

Note

A complete sample project is available at https://github.com/DevExpress-Examples/how-to-customize-a-palette-of-the-choropleth-map-e5108.

Form1.cs

using System.Collections.Generic;
using System.Drawing;
using DevExpress.DashboardCommon;
using DevExpress.XtraEditors;

namespace Dashboard_ChoroplethMapCustomPalette {
    public partial class Form1 : XtraForm {
        public Form1() {
            InitializeComponent();
            // Loads a dashboard that contains a choropleth map with the default palette.
            Dashboard dashboard = new Dashboard();
            dashboard.LoadFromXml(@"..\..\Data\Dashboard.xml");

            // Gets the ValueMap object that provides data for coloring map shapes.
            ChoroplethMapDashboardItem map = (ChoroplethMapDashboardItem)dashboard.Items[0];
            ValueMap populationMap = (ValueMap)map.Maps[0];

            // Creates CustomPalette and CustomScale objects.
            CustomPalette customPalette = new CustomPalette();
            CustomScale customScale = new CustomScale();

            // Creates lists of custom colors and range stops.
            List<Color> customColors = new List<Color>();
            List<double> rangeStops = new List<double>();

            // Specifies that the absolute scale is used to define a set of colors.
            customScale.IsPercent = false;

            // Specifies custom colors and corresponding range stops.   
            customColors.Add(Color.LightBlue);  rangeStops.Add(100000);
            customColors.Add(Color.SkyBlue);    rangeStops.Add(1000000);
            customColors.Add(Color.LightCoral); rangeStops.Add(10000000);
            customColors.Add(Color.Tomato);     rangeStops.Add(100000000);
            customColors.Add(Color.Maroon);     rangeStops.Add(1000000000);

            // Adds custom colors and range stops to a custom palette and corresponding custom scale.
            customPalette.Colors.AddRange(customColors);
            customScale.RangeStops.AddRange(rangeStops);

            // Specifies a custom palette and scale for the ValueMap object.
            populationMap.Palette = customPalette;
            populationMap.Scale = customScale;

            // Sets the customized dashboard as a currently opened dashboard.
            dashboardViewer1.Dashboard = dashboard;
        }
    }
}

Form1.vb

Imports Microsoft.VisualBasic
Imports System.Collections.Generic
Imports System.Drawing
Imports DevExpress.DashboardCommon
Imports DevExpress.XtraEditors

Namespace Dashboard_ChoroplethMapCustomPalette
    Partial Public Class Form1
        Inherits XtraForm
        Public Sub New()
            InitializeComponent()
            ' Loads a dashboard that contains a choropleth map with the default palette.
            Dim dashboard As New Dashboard()
            dashboard.LoadFromXml("..\..\Data\Dashboard.xml")

            ' Gets the ValueMap object that provides data for coloring map shapes.
            Dim map As ChoroplethMapDashboardItem = CType(dashboard.Items(0), ChoroplethMapDashboardItem)
            Dim populationMap As ValueMap = CType(map.Maps(0), ValueMap)

            ' Creates CustomPalette and CustomScale objects.
            Dim customPalette As New CustomPalette()
            Dim customScale As New CustomScale()

            ' Creates lists of custom colors and range stops.
            Dim customColors As New List(Of Color)()
            Dim rangeStops As New List(Of Double)()

            ' Specifies that the absolute scale is used to define a set of colors.
            customScale.IsPercent = False

            ' Specifies custom colors and corresponding range stops.   
            customColors.Add(Color.LightBlue)
            customColors.Add(Color.SkyBlue)
            customColors.Add(Color.LightCoral)
            customColors.Add(Color.Tomato)
            customColors.Add(Color.Maroon)
            rangeStops.Add(100000)
            rangeStops.Add(1000000)
            rangeStops.Add(10000000)
            rangeStops.Add(100000000)
            rangeStops.Add(1000000000)

            ' Adds custom colors and range stops to a custom palette and corresponding custom scale.
            customPalette.Colors.AddRange(customColors)
            customScale.RangeStops.AddRange(rangeStops)

            ' Specifies a custom palette and scale for the ValueMap object.
            populationMap.Palette = customPalette
            populationMap.Scale = customScale

            ' Sets the customized dashboard as a currently opened dashboard.
            dashboardViewer1.Dashboard = dashboard
        End Sub
    End Class
End Namespace

Inheritance

Object

MapScale

CustomScale