Recursive ContainerFromItem

在使用WPF的TreeView時，透過ItemContainerGenerator.ContainerFromItem找尋特定的TreeViewItem，只能找到第一層的節點。第二層以後的節點必須要透過遞迴下去找尋，像是下面這樣：

public DependencyObject ContainerFromItemItems(Control itemsControl, object value) { var dp = itemsControl.ItemContainerGenerator.ContainerFromItem(value);

if (dp != null) return dp;

foreach (var item in itemsControl.Items) { var currentTreeViewItem = itemsControl.ItemContainerGenerator.ContainerFromItem(item);

var childDp = ContainerFromItem(currentTreeViewItem as ItemsControl, value);

if (childDp != null) return childDp; } return null; }

為方便後續使用，這邊筆者稍微整理了一些擴充方法，有需要的自行取用：

using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Windows; using System.Windows.Controls;

public static class ItemsControlExtension { public static DependencyObject ContainerFromItem(this ItemsControl itemsControl, object value) { var dp = itemsControl.ItemContainerGenerator.ContainerFromItem(value);

if (dp != null) return dp;

foreach (var item in itemsControl.Items) { var currentTreeViewItem = itemsControl.ItemContainerGenerator.ContainerFromItem(item);

var childDp = ContainerFromItem(currentTreeViewItem as ItemsControl, value);

if (childDp != null) return childDp; } return null; }

public static T ContainerFromItem(this ItemsControl itemsControl, object value) where T : class { return ContainerFromItem(itemsControl, value) as T; } }

using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Windows; using System.Windows.Controls.Primitives;

public static class SelectorExtension { public static DependencyObject ContainerFromSelectedItem(Selector selector) { var selectedItem = selector.SelectedItem;

if (selectedItem == null) return null;

return selector.ContainerFromItem(selectedItem); }

public static T ContainerFromSelectedItem(Selector selector) where T : class { return ContainerFromSelectedItem(selector) as T; } }

using System.Windows; using System.Windows.Controls;

public static class TreeViewExtension { public static void ClearSelection(this TreeView treeview) { var selectedItem = ContainerFromSelectedItem(treeview);

if (selectedItem == null) return;

selectedItem.IsSelected = false;

}

public static DependencyObject ContainerFromSelectedItem(this TreeView treeview) { var selectedItem = treeview.SelectedItem;

if (selectedItem == null) return null;

return treeview.ContainerFromItem(selectedItem); }

public static T ContainerFromSelectedItem(this TreeView treeview) where T : class { return ContainerFromSelectedItem(treeview) as T; } }