Measurements.BeforeMeasurement Event

Occurs when a user starts ruler creation.

Namespace: DevExpress.XtraMap

Assembly: DevExpress.XtraMap.v20.2.dll

NuGet Package: DevExpress.Win.Map

Declaration

C#

[Browsable(false)]
public event BeforeMeasurementEventHandler BeforeMeasurement

VB.NET

<Browsable(False)>
Public Event BeforeMeasurement As BeforeMeasurementEventHandler

Event Data

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

Property	Description
Cancel	Gets or sets a value indicating whether the event should be canceled. Inherited from CancelEventArgs.
RulerType	Returns the type of the new ruler.
StartPoint	Returns coordinates of the ruler’s start point.
Style	Returns style settings of the new ruler.

Remarks

The Measurements object raises the BeforeMeasurement event after a user sets the ruler’s first point. Use the e.Cancel property to cancel ruler creation. The e.StartPoint property returns the ruler’s first point. To determine the type of ruler that a user wishes to add, use the e.RulerType property.

The example below cancels ruler creation if a ruler starts inside an ellipse:

C#

private void Measurements_BeforeMeasurement(object sender, BeforeMeasurementEventArgs e) {
 MapHitInfo info = this.mapControl1.CalcHitInfo(e.StartPonit);
 if (info.InMapEllipse) {
     e.Cancel = true;
 }    
}

VB.NET

Private Sub Measurements_BeforeMeasurement(ByVal sender As Object, ByVal e As BeforeMeasurementEventArgs)
 Dim info As MapHitInfo = Me.mapControl1.CalcHitInfo(e.StartPonit)
 If info.InMapEllipse Then
     e.Cancel = True
 End If
End Sub