'Declaration Public Overrides NotOverridable Sub OnApplyTemplate()
public override void OnApplyTemplate()
OnApplyTemplate is a .NET framework method exposed by the FrameworkElement. This class overrides it to get the focus site from the control template whenever template gets applied to the control.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2