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How to: Use Chart Tooltips

  • 6 minutes to read

This example demonstrates how to enable and customize chart tooltips at runtime.

To enable tooltips, set the ChartControl.ToolTipEnabled property to true. For more information about chart tooltips, see the Tooltips article.

The following example shows tree series with different tooltip patterns:

  • unboundSeries - a simple unbound series.

    The series shows tooltips with the following pattern:

    Line Series: {A}:{V}

  • unboundSeriesWithTag - an unbound series with the specified SeriesPoint.Tag property for each data point.

    The series shows tooltips with the pattern that references Tag values:

    {A}: {V} ({Test})

  • boundSeries - a series that is bound to the data source.

    The series shows tooltips with the pattern that references data source field values:

    {A}: {V} ({Comment})

View Example: How to show and customize chart tooltips

using DevExpress.XtraCharts;
using System;
using System.Windows.Forms;
using DevExpress.Utils;
using System.Collections.Generic;
using System.Data;

namespace TooltipCustomization {
    public partial class Form1 : Form {
        public Form1() {
            InitializeComponent();
        }
        // Create a data source.  
        public class TestChartData {
            public string Argument { get; set; }
            public double Value { get; set; }
            public string Comment { get; set; }
            public TestChartData(string arguments, double value, string comment) {
                Argument = arguments;
                Value = value;
                Comment = comment;
            }

        }
        private List<TestChartData> CreateChartData() {
            var list = new List<TestChartData>();
            list.Add(new TestChartData("A", 4, "comment for A"));
            list.Add(new TestChartData("B", 2, "comment for B"));
            list.Add(new TestChartData("C", 17, "comment for C"));
            list.Add(new TestChartData("D", 4, "comment for D"));
            list.Add(new TestChartData("E", 17, "comment for E"));
            list.Add(new TestChartData("F", 12, "comment for F"));
            list.Add(new TestChartData("G", 15, "comment for G"));
            return list;
        }

        private void Form1_Load(object sender, EventArgs e) {
            // Create an empty chart.
            ChartControl chartControl = new ChartControl();

            // Add the chart to the form.
            chartControl.Dock = DockStyle.Fill;
            this.Controls.Add(chartControl);

            // Create a series and add points to it.
            Series boundSeries = new Series("Bound Series", ViewType.Line);
            // Assign the created data source to the series.
            boundSeries.DataSource = CreateChartData();
            boundSeries.ArgumentScaleType = ScaleType.Auto;
            boundSeries.ArgumentDataMember = "Argument";
            boundSeries.ValueScaleType = ScaleType.Numerical;
            boundSeries.ValueDataMembers.AddRange(new string[] { "Value" });

            Series unboundSeries = new Series("Unbound Series", ViewType.Line);
            unboundSeries.Points.Add(new SeriesPoint("A", new double[] { 9 }));
            unboundSeries.Points.Add(new SeriesPoint("B", new double[] { 7 }));
            unboundSeries.Points.Add(new SeriesPoint("C", new double[] { 23 }));
            unboundSeries.Points.Add(new SeriesPoint("D", new double[] { 9 }));
            unboundSeries.Points.Add(new SeriesPoint("E", new double[] { 23 }));
            unboundSeries.Points.Add(new SeriesPoint("F", new double[] { 17 }));
            unboundSeries.Points.Add(new SeriesPoint("G", new double[] { 20 }));

            Series unboundSeriesWithTag = new Series("Unbound Series with Tag", ViewType.Line);
            unboundSeriesWithTag.Points.Add(new SeriesPoint("A", 2) { Tag = new { Test = "TestValue" } });
            unboundSeriesWithTag.Points.Add(new SeriesPoint("B", 0) { Tag = new { Test = "TestValue" } });
            unboundSeriesWithTag.Points.Add(new SeriesPoint("C", 15) { Tag = new { Test = "TestValue" } });
            unboundSeriesWithTag.Points.Add(new SeriesPoint("D", 2) { Tag = new { Test = "TestValue" } });
            unboundSeriesWithTag.Points.Add(new SeriesPoint("E", 15) { Tag = new { Test = "TestValue" } });
            unboundSeriesWithTag.Points.Add(new SeriesPoint("F", 10) { Tag = new { Test = "TestValue" } });
            unboundSeriesWithTag.Points.Add(new SeriesPoint("G", 13) { Tag = new { Test = "TestValue" } });

            // Add the series to the chart.
            chartControl.Series.AddRange(unboundSeries, unboundSeriesWithTag, boundSeries);
            // Enable data point markers.
            ((LineSeriesView)unboundSeries.View).MarkerVisibility = DefaultBoolean.True;
            ((LineSeriesView)unboundSeriesWithTag.View).MarkerVisibility = DefaultBoolean.True;
            ((LineSeriesView)boundSeries.View).MarkerVisibility = DefaultBoolean.True;
            // Disable a crosshair cursor.
            chartControl.CrosshairEnabled = DefaultBoolean.False;

            // Enable chart tooltips. 
            chartControl.ToolTipEnabled = DefaultBoolean.True;

            // Show a tooltip's beak.
            ToolTipController controller = new ToolTipController();
            chartControl.ToolTipController = controller;
            controller.ShowBeak = true;

            // Change the default tooltip mouse position to relative position.
            ToolTipRelativePosition relativePosition = new ToolTipRelativePosition();
            chartControl.ToolTipOptions.ToolTipPosition = relativePosition;

            // Specify the tooltip relative position offsets.  
            relativePosition.OffsetX = 2;
            relativePosition.OffsetY = 2;

            // Specify the tooltip point pattern.
            unboundSeries.ToolTipPointPattern = "Line Series: {A}:{V}";
            unboundSeriesWithTag.ToolTipPointPattern = "{A}: {V} ({Test})";
            boundSeries.ToolTipPointPattern = "{A}: {V} ({Comment})";
        }
    }
}