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FSI.BT.IR.Tools/FSI.Lib/NLogViewer/Extensions/DependencyObjectExtensions.cs
Maier Stephan SI 0b0508b042 Sicherung
2023-01-16 16:04:47 +01:00

73 lines
3.0 KiB
C#

using System.Collections.Generic;
using System.Windows;
using System.Windows.Media;
namespace DJ.Extensions
{
public static class DependencyObjectExtensions
{
/// <summary>
/// Analyzes both visual and logical tree in order to find all elements of a given
/// type that are descendants of the <paramref name="source"/> item.
/// </summary>
/// <typeparam name="T">The type of the queried items.</typeparam>
/// <param name="source">The root element that marks the source of the search. If the
/// source is already of the requested type, it will not be included in the result.</param>
/// <param name="uid">The UID of the <see cref="UIElement"/></param>
/// <returns>All descendants of <paramref name="source"/> that match the requested type.</returns>
public static T FindChildByUid<T>(this DependencyObject source, string uid) where T : UIElement
{
if (source != null)
{
var childs = GetChildObjects(source);
foreach (DependencyObject child in childs)
{
//analyze if children match the requested type
if (child != null && child is T dependencyObject && dependencyObject.Uid.Equals(uid))
{
return dependencyObject;
}
var descendant = FindChildByUid<T>(child, uid);
if (descendant != null)
return descendant;
}
}
return null;
}
/// <summary>
/// This method is an alternative to WPF's
/// <see cref="VisualTreeHelper.GetChild"/> method, which also
/// supports content elements. Keep in mind that for content elements,
/// this method falls back to the logical tree of the element.
/// </summary>
/// <param name="parent">The item to be processed.</param>
/// <returns>The submitted item's child elements, if available.</returns>
public static IEnumerable<DependencyObject> GetChildObjects(this DependencyObject parent)
{
if (parent == null) yield break;
if (parent is ContentElement || parent is FrameworkElement)
{
//use the logical tree for content / framework elements
foreach (object obj in LogicalTreeHelper.GetChildren(parent))
{
var depObj = obj as DependencyObject;
if (depObj != null) yield return (DependencyObject) obj;
}
}
else
{
//use the visual tree per default
int count = VisualTreeHelper.GetChildrenCount(parent);
for (int i = 0; i < count; i++)
{
yield return VisualTreeHelper.GetChild(parent, i);
}
}
}
}
}