| public static TryGetVisualStateGroup ( DependencyObject dependencyObject, string groupName ) : VisualStateGroup | ||
| dependencyObject | DependencyObject | The dependency object. |
| groupName | string | The visual state group's name. |
| return | VisualStateGroup | |
public static VisualStateGroup TryGetVisualStateGroup(DependencyObject dependencyObject, string groupName)
{
FrameworkElement root = GetImplementationRoot(dependencyObject);
if(root == null)
{
return null;
}
// ReSharper disable ReplaceWithSingleCallToFirstOrDefault
// ReSharper disable AssignNullToNotNullAttribute
return VisualStateManager.GetVisualStateGroups(root)
// ReSharper restore AssignNullToNotNullAttribute
.OfType<VisualStateGroup>()
.Where(group => string.CompareOrdinal(groupName, group.Name) == 0)
.FirstOrDefault();
// ReSharper restore ReplaceWithSingleCallToFirstOrDefault
}
} /// <summary>
/// Should be called by the parent control before the base
/// OnApplyTemplate method is called.
/// </summary>
public void BeforeOnApplyTemplate()
{
if (UsesClosingVisualState)
{
// Unhook the event handler for the popup closed visual state group.
// This code is used to enable visual state transitions before
// actually setting the underlying Popup.IsOpen property to false.
VisualStateGroup groupPopupClosed = VisualStates.TryGetVisualStateGroup(Parent, VisualStates.GroupPopup);
if (null != groupPopupClosed)
{
groupPopupClosed.CurrentStateChanged -= OnPopupClosedStateChanged;
UsesClosingVisualState = false;
}
}
if (Popup != null)
{
Popup.Closed -= Popup_Closed;
}
}