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V24.2

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HeatmapControl.CustomizeHeatmapToolTip Event

Occurs before a tooltip is invoked and allows to customize tooltip content based on heatmap cell arguments and values.

Namespace: DevExpress.XtraCharts.Heatmap

Assembly: DevExpress.XtraCharts.v24.2.UI.dll

NuGet Package: DevExpress.Win.Charts

#Declaration

public event CustomizeHeatmapToolTipEventHandler CustomizeHeatmapToolTip

#Event Data

The CustomizeHeatmapToolTip event's data class is CustomizeHeatmapToolTipEventArgs. The following properties provide information specific to this event:

Property Description
HeatmapCell Returns a heatmap cell for which a tooltip is shown.
Text Gets or sets the cell tooltip text.
Title Gets or sets the cell tooltip title.

#Remarks

The following example shows how to use the HeatmapControl.CustomizeHeatmapToolTip event to modify tooltip content based on the cell value for which the tooltip is shown.

A tooltip customized in the CustomizeHeatmapToolTip handler.

Follow the steps below to enable and customize tooltips:

The code below applies a custom format to tooltip text if a heatmap cell value is more than the specified value:

const int ThresholdValue = 50;

public Form1() {
    InitializeComponent();
    // ...
    heatmap.ToolTipEnabled = true;
    heatmap.ToolTipController = new DevExpress.Utils.ToolTipController { AllowHtmlText = true };
    heatmap.CustomizeHeatmapToolTip += OnHeatmapCustomizeHeatmapToolTip;
}

private void OnHeatmapCustomizeHeatmapToolTip(object sender, CustomizeHeatmapToolTipEventArgs e) {
    double cellValue = (double)e.HeatmapCell.ColorValue;
    if (cellValue > ThresholdValue) {
        e.Title = "Sale Info";
        e.Text = $"Total: <color=green>${cellValue}K</color>";
    }
}
See Also