Sets the value of the SummaryTaskTemplate attached property to a specified element such as a task item, overriding the default value provided by the GanttChartView control. The SummaryTaskTemplate property value indicates the data template to be used to display a task if it is a summary task (has child tasks). Overriding the default value for a specific item requires that the IsItemAppearanceApplied property of the control to be set to true.

public static void SetSummaryTaskTemplate(
	DependencyObject element,
	DataTemplate summaryTaskTemplate
)

Public Shared Sub SetSummaryTaskTemplate ( _
	element As DependencyObject, _
	summaryTaskTemplate As DataTemplate _
)