Skip to main content
All docs
V24.1

HeatmapDataSourceAdapter.DataSource Property

Gets or sets the data source from which the adapter loads data.

Namespace: DevExpress.XtraCharts.Heatmap

Assembly: DevExpress.XtraCharts.v24.1.dll

NuGet Package: DevExpress.Charts

Declaration

public object DataSource { get; set; }

Property Value

Type Description
Object

An object that is a data source.

Remarks

To specify the DataSource property, you can use an object that implements any of the following interfaces: IList, IListSource, or IBindingList.

Example

The following example shows how to create a heatmap and bind it to a data source. In this example, the heatmap obtains data from an XML file.

A heatmap that uses a Data Source Adapter to load data.

Follow the steps below to create a heatmap:

using DevExpress.XtraCharts;
using DevExpress.XtraCharts.Heatmap;
using System;
using System.Data;
using System.Drawing;
using System.IO;
using System.Windows.Forms;

namespace HeatmapChart {
    public partial class Form1 : Form {
        public Form1() {
            InitializeComponent();
        }
        private void Form1_Load(object sender, EventArgs e) {
            HeatmapControl heatmap = new HeatmapControl();
            heatmap.Dock = DockStyle.Fill;
            this.Controls.Add(heatmap);

            Palette palette = new Palette("Custom") {
                Color.Red,
                Color.White,
                Color.Green
            };

            HeatmapRangeColorProvider colorProvider = new HeatmapRangeColorProvider() {
                Palette = palette,
                ApproximateColors = true
            };

            colorProvider.RangeStops.Add(new HeatmapRangeStop(0, HeatmapRangeStopType.Percentage));
            colorProvider.RangeStops.Add(new HeatmapRangeStop(-10, HeatmapRangeStopType.Absolute));
            colorProvider.RangeStops.Add(new HeatmapRangeStop(-2.5, HeatmapRangeStopType.Absolute));
            colorProvider.RangeStops.Add(new HeatmapRangeStop(0, HeatmapRangeStopType.Absolute));
            colorProvider.RangeStops.Add(new HeatmapRangeStop(2.5, HeatmapRangeStopType.Absolute));
            colorProvider.RangeStops.Add(new HeatmapRangeStop(10, HeatmapRangeStopType.Absolute));
            colorProvider.RangeStops.Add(new HeatmapRangeStop(1, HeatmapRangeStopType.Percentage));

            heatmap.ColorProvider = colorProvider;

            DataTable data = CreateDataSet("BalanceOfTrade.xml");

            heatmap.DataAdapter = new HeatmapDataSourceAdapter() {
                XArgumentDataMember = "Country",
                YArgumentDataMember = "Product",
                ColorDataMember = "Value",
                DataSource = data                
            };

            heatmap.Titles.Add(new HeatmapTitle { Text = "Balance of Trade" });

            heatmap.Label.Visible = true;
            heatmap.Label.Font = new Font("SegoeUI", 6);
            heatmap.Label.Pattern = "{V}";

            heatmap.ToolTipEnabled = true;
            heatmap.ToolTipController = new DevExpress.Utils.ToolTipController {
                AllowHtmlText = true,
                ToolTipLocation = DevExpress.Utils.ToolTipLocation.RightTop,
                ShowBeak = true
            };
            heatmap.ToolTipTextPattern = "X: <b>{X}</b>\nY: <b>{Y}</b>";
        }
        public static DataTable CreateDataSet(string xmlFileName) {
            string filePath = GetRelativePath(xmlFileName);
            if (!string.IsNullOrWhiteSpace(filePath)) {
                DataSet dataSet = new DataSet();
                dataSet.ReadXml(filePath);
                if (dataSet.Tables.Count > 0)
                    return dataSet.Tables[0];
            }
            return null;
        }
        public static string GetRelativePath(string name) {
            name = "Data\\" + name;
            DirectoryInfo dir = new DirectoryInfo(Application.StartupPath);
            for (int i = 0; i <= 10; i++) {
                string filePath = Path.Combine(dir.FullName, name);
                if (File.Exists(filePath))
                    return filePath;
                dir = Directory.GetParent(dir.FullName);
            }
            return string.Empty;
        }
    }
}

The XML file structure looks as follows:

Show XML
<?xml version="1.0" standalone="yes"?>
<BalanceOfTrade xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
    <xs:element name="Item">
      <xs:complexType>
        <xs:sequence>
          <xs:element name="Country" type="xs:string"/>
          <xs:element name="Product" type="xs:string"/>
          <xs:element name="Value" type="xs:double"/>
        </xs:sequence>
      </xs:complexType>
    </xs:element>
  </xs:schema>
  <Item>
    <Country>China</Country>
    <Product>Computer</Product>
    <Value>-151.9</Value>
  </Item>
  <Item>
    <Country>China</Country>
    <Product>Oil, Gas, Minerals</Product>
    <Value>1.9</Value>
  </Item>
  <Item>
    <Country>China</Country>
    <Product>Transportation</Product>
    <Value>10.9</Value>
  </Item>
  <Item>
    <Country>China</Country>
    <Product>Apparel</Product>
    <Value>-56.3</Value>
  </Item>
  <!--...-->
</BalanceOfTrade>     

The following code snippet (auto-collected from DevExpress Examples) contains a reference to the DataSource property.

Note

The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.

See Also