/// <summary>
/// Finds a Child of a given item in the visual tree.
/// </summary>
/// <param name="parent">A direct parent of the queried item.</param>
/// <typeparam name="T">The type of the queried item.</typeparam>
/// <param name="childName">x:Name or Name of child. </param>
/// <returns>The first parent item that matches the submitted type parameter.
/// If not matching item can be found,
/// a null parent is being returned.</returns>
public static T ChildOfType <T>(this DependencyObject parent, string childName = null)
where T : DependencyObject
{
// Confirm parent and childName are valid.
if (parent == null)
{
return(null);
}
if (childName != null)
{
return(parent.ChildrenOfType <T>()
.FirstOrDefault(x =>
{
var xf = x as FrameworkElement;
if (xf == null)
{
return false;
}
return xf.Name == childName;
}));
}
return(parent.ChildrenOfType <T>().FirstOrDefault());
}
internal static T GetFirstDescendantOfType <T>(this DependencyObject target) where T : DependencyObject
{
var obj = target as T;
if (obj != null)
{
return(obj);
}
return(target.ChildrenOfType <T>().FirstOrDefault());
}
/// <summary>
/// Does a deep search of the element tree, trying to find a descendant of the given type
/// (including the element itself).
/// </summary>
/// <returns>True if the target is one of the elements.</returns>
internal static T GetFirstDescendantOfType <T>(this DependencyObject target)
where T : DependencyObject
{
T t = (T)(target as T);
if (t == null)
{
t = target.ChildrenOfType <T>().FirstOrDefault <T>();
}
return(t);
}
/// <summary>
/// Does a deep search of the element tree, trying to find a descendant of the given type
/// (including the element itself).
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="target">The target<see cref="DependencyObject"/></param>
/// <returns>True if the target is one of the elements.</returns>
internal static T GetFirstDescendantOfType <T>(this DependencyObject target) where T : DependencyObject
{
return(target as T ?? target.ChildrenOfType <T>().FirstOrDefault());
}
/// <summary>
/// The FindChildrenByType
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="element">The element<see cref="DependencyObject"/></param>
/// <returns>The <see cref="IEnumerable{T}"/></returns>
internal static IEnumerable <T> FindChildrenByType <T>(this DependencyObject element) where T : DependencyObject
{
return(element.ChildrenOfType <T>());
}
/// <summary>
/// Finds child element of the specified type. Uses breadth-first search.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="element">The target <see cref="DependencyObject"/> which children will be traversed.</param>
/// <returns>The first child element that is of the specified type.</returns>
public static T FindChildByType <T>(this DependencyObject element) where T : DependencyObject
{
return(element.ChildrenOfType <T>().FirstOrDefault());
}
