kategorie fix highlight current value

FasdDesktopUi/Basics/UserControls/HierarchicalSelectionControl.xaml.cs

@@ -115,6 +115,7 @@ namespace FasdDesktopUi.Basics.UserControls
             searchTextBox?.Focus();
             searchTextBox?.SelectAll();
             suppressTreeSelectionChanged = false;
+            SyncTreeSelectionWithSelectedItem(bringIntoView: true);
             LogEntry($"[CategoryPicker] DropDownOpened. Selected={SelectedItem?.FullPath ?? "<null>"}");
             DropDownOpened?.Invoke(this, e);
         }
@@ -203,6 +204,7 @@ namespace FasdDesktopUi.Basics.UserControls
                 }
 
                 TryExpandToSelectedItem();
+                SyncTreeSelectionWithSelectedItem(bringIntoView: false);
                 return;
             }
 
@@ -220,6 +222,9 @@ namespace FasdDesktopUi.Basics.UserControls
                 clone.SetExpandedRecursive(true);
                 visibleItems.Add(clone);
             }
+            
+            // If the selected item is part of current results, keep it visually selected.
+            SyncTreeSelectionWithSelectedItem(bringIntoView: false);
         }
 
         private void TryExpandToSelectedItem()
@@ -238,6 +243,93 @@ namespace FasdDesktopUi.Basics.UserControls
             }
         }
 
+        private void SyncTreeSelectionWithSelectedItem(bool bringIntoView)
+        {
+            if (SelectedItem == null || string.IsNullOrWhiteSpace(SelectedItem.Id))
+                return;
+
+            EnsureTemplateParts();
+            if (treeViewControl == null)
+                return;
+
+            // Wait for popup/template layout to finish so item containers are generated.
+            Dispatcher.BeginInvoke(new Action(() =>
+            {
+                var target = FindVisibleItemById(VisibleItems, SelectedItem.Id);
+                if (target == null)
+                    return;
+
+                var ancestor = target.Parent;
+                while (ancestor != null)
+                {
+                    ancestor.IsExpanded = true;
+                    ancestor = ancestor.Parent;
+                }
+
+                treeViewControl.UpdateLayout();
+                var targetContainer = GetTreeViewItemContainer(treeViewControl, target);
+                if (targetContainer == null)
+                    return;
+
+                suppressTreeSelectionChanged = true;
+                try
+                {
+                    targetContainer.IsSelected = true;
+                    if (bringIntoView)
+                        targetContainer.BringIntoView();
+                }
+                finally
+                {
+                    suppressTreeSelectionChanged = false;
+                }
+            }), DispatcherPriority.Loaded);
+        }
+
+        private static HierarchicalSelectionItem FindVisibleItemById(IEnumerable<HierarchicalSelectionItem> items, string id)
+        {
+            if (items == null || string.IsNullOrWhiteSpace(id))
+                return null;
+
+            foreach (var item in items)
+            {
+                if (item == null)
+                    continue;
+
+                if (string.Equals(item.Id, id, StringComparison.OrdinalIgnoreCase))
+                    return item;
+
+                var childMatch = FindVisibleItemById(item.Children, id);
+                if (childMatch != null)
+                    return childMatch;
+            }
+
+            return null;
+        }
+
+        private static TreeViewItem GetTreeViewItemContainer(ItemsControl root, object targetItem)
+        {
+            if (root == null || targetItem == null)
+                return null;
+
+            var directContainer = root.ItemContainerGenerator.ContainerFromItem(targetItem) as TreeViewItem;
+            if (directContainer != null)
+                return directContainer;
+
+            foreach (var child in root.Items)
+            {
+                var childContainer = root.ItemContainerGenerator.ContainerFromItem(child) as TreeViewItem;
+                if (childContainer == null)
+                    continue;
+
+                childContainer.UpdateLayout();
+                var result = GetTreeViewItemContainer(childContainer, targetItem);
+                if (result != null)
+                    return result;
+            }
+
+            return null;
+        }
+
         private void EnsureTemplateParts()
         {
             if (treeViewControl == null)