ChartControl.ObjectHotTracked Event
Occurs before any chart element is hot-tracked at runtime.
Namespace: DevExpress.XtraCharts
Assembly: DevExpress.XtraCharts.v18.2.UI.dll
Declaration
public event HotTrackEventHandler ObjectHotTrackedPublic Event ObjectHotTracked As HotTrackEventHandlerEvent Data
The ObjectHotTracked event's data class is HotTrackEventArgs. The following properties provide information specific to this event:
| Property | Description |
|---|---|
| AdditionalObject | Provides access to an object related to the object being hit. The returned value depends on the HotTrackEventArgs.Object type and hit point location. |
| Cancel | Gets or sets whether the hot-tracking should be cancelled. |
| HitInfo | Gets details on the chart elements located at the point where an end-user has clicked when hot-tracking or selecting a chart element at runtime. |
| Object | Gets the chart element, for which the event was raised. |
Remarks
If the ChartControl.RuntimeHitTesting property is set to true, end-users will be able to hot-track chart elements.
Handle the ObjectHotTracked event if you want to perform specific actions when an end-user hot-tracks a chart's elements, or if you want to disable the hot-tracking of particular elements. Note that the currently hot-tracked element of the chart can be accessed via the HotTrackEventArgs.Object property.
NOTE
If you handle the ObjectHotTracked event, it will be raised and information on hit-testing will be collected, regardless of the current ChartControl.RuntimeHitTesting property value.
Examples
This example demonstrates how to implement custom hot-tracking and selection of the chart's elements at runtime.
NOTE
To enable runtime hot-tracking and selection, the ChartControl.RuntimeSelection property should be set to true.
If you want to change the default hot-tracking and selection, you should handle the ChartControl.ObjectHotTracked and ChartControl.ObjectSelected events, implement your custom hot-tracking and selection approaches and set the Cancel property to true.
For example, the code below illustrates how to disable selection and hot-tracking of a chart's diagram.
using DevExpress.XtraCharts;
// ...
private void chartControl1_ObjectHotTracked(object sender, HotTrackEventArgs e) {
// Prevent the chart's diagram from being hot-tracked.
if (e.Object is Diagram)
e.Cancel = true;
}
private void chartControl1_ObjectSelected(object sender, HotTrackEventArgs e) {
// Prevent the chart's Diagram from being selected.
if (e.Object is Diagram)
e.Cancel = true;
}