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HeatmapProvider.Colorizer Property

Gets or sets the Choropleth colorizer used to paint the heatmap.

Namespace: DevExpress.XtraMap

Assembly: DevExpress.XtraMap.v19.2.dll

Declaration

[DefaultValue(null)]
public ChoroplethColorizer Colorizer { get; set; }
<DefaultValue(Nothing)>
Public Property Colorizer As ChoroplethColorizer

Property Value

Type Default Description
ChoroplethColorizer

null

A Choropleth colorizer that the Map Control uses to paint the heatmap.

Examples

This example shows how to create a heatmap layer for the Map Control.

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

namespace HeatMapSample {
    public partial class Form1 : Form {
        public Form1() {
            InitializeComponent();
        }
        private void Form1_Load(object sender, EventArgs e) {

            ImageLayer bingLayer = new ImageLayer();
            bingLayer.DataProvider = new BingMapDataProvider { BingKey = "Your Bing Maps key here." };
            mapControl1.Layers.Add(bingLayer);

            ChoroplethColorizer colorizer = new ChoroplethColorizer();
            colorizer.RangeStops.AddRange(new double[] { 0.1, 0.2, 0.7, 1 });
            colorizer.ColorItems.Add(new ColorizerColorItem(Color.FromArgb(50, 128, 255, 0)));
            colorizer.ColorItems.Add(new ColorizerColorItem(Color.FromArgb(255, 255, 255, 0)));
            colorizer.ColorItems.Add(new ColorizerColorItem(Color.FromArgb(255, 234, 72, 58)));
            colorizer.ColorItems.Add(new ColorizerColorItem(Color.FromArgb(255, 162, 36, 25)));
            colorizer.ApproximateColors = true;

            HeatmapDataSourceAdapter adapter = new HeatmapDataSourceAdapter();
            adapter.Mappings.XCoordinate = "glon"; // The data source field name that provides x-coordinates.
            adapter.Mappings.YCoordinate = "glat"; // The data source field name that provides y-coordinates.
            adapter.DataSource = LoadData("../../Data/Earthquakes.xml", "Row");

            HeatmapProvider provider = new HeatmapProvider();
            provider.PointSource = adapter;
            provider.Algorithm = new HeatmapDensityBasedAlgorithm { PointRadius = 8 };
            provider.Colorizer = colorizer;

            ImageLayer heatmapLayer = new ImageLayer();
            heatmapLayer.DataProvider = provider;
            mapControl1.Layers.Add(heatmapLayer);

            ColorScaleLegend legend = new ColorScaleLegend();
            legend.Header = "Seismic Density";
            legend.EnableGradientScale = true;
            legend.Layer = heatmapLayer;
            legend.HeaderStyle.Font = new Font("Tahoma", 12F);
            mapControl1.Legends.Add(legend);
        }
        DataTable LoadData(string filePath, string tableName) {
            DataSet xmlDataSet = new DataSet("XML DataSet");
            xmlDataSet.ReadXml(filePath);
            return xmlDataSet.Tables[tableName];
        }
    }
}
See Also