XYDiagram2D.BeforeScroll Event

Occurs before the diagram is scrolled.

Namespace: DevExpress.Xpf.Charts

Assembly: DevExpress.Xpf.Charts.v23.2.dll

NuGet Package: DevExpress.Wpf.Charts

Declaration

C#

public event XYDiagram2DBeforeScrollEventHandler BeforeScroll

VB.NET

Public Event BeforeScroll As XYDiagram2DBeforeScrollEventHandler

Event Data

The BeforeScroll event's data class is XYDiagram2DBeforeScrollEventArgs. The following properties provide information specific to this event:

Property	Description
Axis	Returns the scrolled axis.
Cancel	Gets or sets the value that specifies whether scrolling is canceled.
Handled	Gets or sets a value that indicates the present state of the event handling for a routed event as it travels the route. Inherited from RoutedEventArgs.
NewRange	Returns information about the zoomed axis’s new visual range.
OriginalSource	Gets the original reporting source as determined by pure hit testing, before any possible Source adjustment by a parent class. Inherited from RoutedEventArgs.
RoutedEvent	Gets or sets the RoutedEvent associated with this RoutedEventArgs instance. Inherited from RoutedEventArgs.
Source	Gets or sets a reference to the object that raised the event. Inherited from RoutedEventArgs.

The event data class exposes the following methods:

Method	Description
InvokeEventHandler(Delegate, Object)	When overridden in a derived class, provides a way to invoke event handlers in a type-specific way, which can increase efficiency over the base implementation. Inherited from RoutedEventArgs.
OnSetSource(Object)	When overridden in a derived class, provides a notification callback entry point whenever the value of the Source property of an instance changes. Inherited from RoutedEventArgs.

Remarks

You can handle the XYDiagram2D.BeforeScroll event to cancel a scroll operation. Set the e.Cancel property to true for this purpose.

C#

private void XYDiagram2D_BeforeScroll(object sender, XYDiagram2DBeforeScrollEventArgs e) {
    if (e.Axis is AxisY2D) {
        e.Cancel = true;
    }
}

VB.NET

Private Sub XYDiagram2D_BeforeScroll(ByVal sender As Object, ByVal e As XYDiagram2DBeforeScrollEventArgs)
    If TypeOf e.Axis Is AxisY2D Then
        e.Cancel = True
    End If
End Sub