public void PreHide()
{
var backup = new GridExpandBehaviorBackupInfo(Element);
FrameworkElementAtt.SetGridExpanderBehavior_Backup(Element, backup);
if (IsHorizontal)
{
Element.Width = Element.ActualWidth;
Element.HorizontalAlignment = Dock == Dock.Right ? HorizontalAlignment.Right : HorizontalAlignment.Left;
}
else
{
Element.Height = Element.ActualHeight;
Element.VerticalAlignment = Dock == Dock.Bottom ? VerticalAlignment.Bottom : VerticalAlignment.Top;
}
}
public static void SetGridExpanderBehavior_Backup(DependencyObject obj, GridExpandBehaviorBackupInfo value)
{
obj.SetValue(GridExpanderBehavior_BackupProperty, value);
}