public static TChild GetLastVisualChild <TChild>(this DependencyObject obj, Predicate <TChild> predicate = null)
where TChild : DependencyObject
{
if (obj == null)
{
return(null);
}
var count = VisualTreeHelper.GetChildrenCount(obj);
for (int i = count - 1; i >= 0; i--)
{
var c = VisualTreeHelper.GetChild(obj, i);
var r = c as TChild;
if (r != null && (predicate == null || predicate(r)))
{
return(r);
}
r = GetLastVisualChild(c, predicate);
if (r != null)
{
return(r);
}
}
return(null);
}
private static IEnumerable <DependencyObject> GetAllVisualChildren(DependencyObject source)
{
var stack = new Queue <DependencyObject>();
stack.Enqueue(source);
while (stack.Any())
{
DependencyObject current = stack.Dequeue();
int childCount = WPFVisualTreeHelper.GetChildrenCount(current);
for (int i = 0; i < childCount; i++)
{
var child = WPFVisualTreeHelper.GetChild(current, i);
yield return(child);
stack.Enqueue(child);
}
}
}
public static IEnumerable <T> GetVisualChildren <T>(this DependencyObject source) where T : DependencyObject
{
if (source == null)
{
throw new ArgumentNullException(nameof(source));
}
return(GetVisualChildrenImplementation());
IEnumerable <T> GetVisualChildrenImplementation()
{
int count = WPFVisualTreeHelper.GetChildrenCount(source);
for (int i = 0; i < count; i++)
{
if (WPFVisualTreeHelper.GetChild(source, i) is T child)
{
yield return(child);
}
}
}
}
public static TChild GetFirstVisualChild <TChild>(this DependencyObject obj)
where TChild : DependencyObject
{
var count = VisualTreeHelper.GetChildrenCount(obj);
for (int i = 0; i < count; i++)
{
var c = VisualTreeHelper.GetChild(obj, i);
var r = c as TChild;
if (r != null)
{
return(r);
}
else
{
r = GetFirstVisualChild <TChild>(c);
if (r != null)
{
return(r);
}
}
}
return(null);
}
public static DependencyObject GetFirstVisualChild(this DependencyObject obj)
{
return(VisualTreeHelper.GetChild(obj, 0));
}
public static DependencyObject GetParent(this DependencyObject obj)
{
return(obj is System.Windows.Media.Visual ? VisualTreeHelper.GetParent(obj) : LogicalTreeHelper.GetParent(obj));
}
public static DependencyObject GetVisualParent(this DependencyObject obj)
{
return(VisualTreeHelper.GetParent(obj));
}
