wpf-devexpress-dot-xpf-dot-gantt-dot-ganttview-047ee4db.md
Occurs when timescale rulers are visually changed and allows you to edit timescale rulers. This is a routed event.
Namespace : DevExpress.Xpf.Gantt
Assembly : DevExpress.Xpf.Gantt.v25.2.dll
NuGet Package : DevExpress.Wpf.Gantt
public event EventHandler<RequestTimescaleRulersEventArgs> RequestTimescaleRulers
Public Event RequestTimescaleRulers As EventHandler(Of RequestTimescaleRulersEventArgs)
The RequestTimescaleRulers event's data class is RequestTimescaleRulersEventArgs. The following properties provide information specific to this event:
| Property | Description |
|---|---|
| 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. |
| NonworkingDayVisibility | Gets or sets the nonworking day visibility at a current zoom level. |
| NonworkingTimeVisibility | Gets or sets the nonworking time visibility at a current zoom level. |
| 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. |
| TimescaleRulers | Get or sets a collection of timescale rulers displayed at the current zoom level. |
| Zoom | Gets the current zoom. |
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. |
The RequestTimescaleRulers event occurs on init, when the Gantt area is zoomed and when the TimescaleRulerCount property value is changed.
Handle the RequestTimescaleRulers event to dynamically change the following:
a set of rulers displayed within the timescales (RequestTimescaleRulersEventArgs.TimescaleRulers)
visibility of nonworking days and nonworking time (RequestTimescaleRulersEventArgs.NonworkingDayVisibility and RequestTimescaleRulersEventArgs.NonworkingTimeVisibility)
private void view_RequestTimescaleRulers(object sender, DevExpress.Xpf.Gantt.RequestTimescaleRulersEventArgs e) {
// Remove a ruler from timescale
e.TimescaleRulers.RemoveAt(1);
// Add a ruler that indicates hours
e.TimescaleRulers.Add(new DevExpress.Xpf.Gantt.TimescaleRuler(DevExpress.Xpf.Gantt.TimescaleUnit.Hour));
// Add a ruler that indicates 30 minute ranges
e.TimescaleRulers.Add(new DevExpress.Xpf.Gantt.TimescaleRuler(DevExpress.Xpf.Gantt.TimescaleUnit.Minute, 30));
// Nonworking dates and nonworking time are not indicated with a specific background
e.NonworkingDayVisibility = Visibility.Hidden;
e.NonworkingTimeVisibility = Visibility.Hidden;
}
Private Sub view_RequestTimescaleRulers(ByVal sender As Object, ByVal e As DevExpress.Xpf.Gantt.RequestTimescaleRulersEventArgs)
' Remove a ruler from timescale
e.TimescaleRulers.RemoveAt(1)
' Add a ruler that indicates hours
e.TimescaleRulers.Add(New DevExpress.Xpf.Gantt.TimescaleRuler(DevExpress.Xpf.Gantt.TimescaleUnit.Hour))
' Add a ruler that indicates 30 minute ranges
e.TimescaleRulers.Add(New DevExpress.Xpf.Gantt.TimescaleRuler(DevExpress.Xpf.Gantt.TimescaleUnit.Minute, 30))
' Nonworking dates and nonworking time are not indicated with a specific background
e.NonworkingDayVisibility = Visibility.Hidden
e.NonworkingTimeVisibility = Visibility.Hidden
End Sub
The RequestTimescaleRulers event allows you to add timescale rulers with custom formats:
Create a class that implements IFormatProvider and ICustomFormatter interfaces.
In this class, specify the ruler’s text and format. The following code sample displays months or two-month ranges based on the zoom level:
Add a new timescale ruler and pass your custom format to its FormatProvider property:
See Also