windowsforms-devexpress-dot-xtratreelist-dot-treelist-8696558a.md
Gets the collection of selected nodes.
Namespace : DevExpress.XtraTreeList
Assembly : DevExpress.XtraTreeList.v25.2.dll
NuGet Packages : DevExpress.Win.Navigation, DevExpress.Win.TreeList
[Browsable(false)]
public TreeListSelection Selection { get; }
<Browsable(False)>
Public ReadOnly Property Selection As TreeListSelection
| Type |
|---|
| DevExpress.XtraTreeList.TreeListSelection |
When a user navigates through the TreeList control, the TreeList.Selection collection contains a selected node. If the TreeListOptionsSelection.MultiSelect option is active and miltiple nodes are selected, the TreeList.Selection collection contains all selected nodes.
To enumerate elements of the collection, you can use the foreach ( For Each in Visual Basic) statement, as the following code snippet demonstrates.
string columnName = "DEPARTMENT";
int i = 0;
foreach (DevExpress.XtraTreeList.Nodes.TreeListNode treeListNode in treeList1.Selection) {
//Set a new value in the Department column for each selected node.
treeListNode.SetValue(columnName, "Department" + i++.ToString());
}
Dim columnName As String = "DEPARTMENT"
Dim i As Integer = 0
For Each treeListNode As DevExpress.XtraTreeList.Nodes.TreeListNode In TreeList1.Selection
'Set a new value in the Department column for each selected node.
treeListNode.SetValue(columnName, "Department" + i.ToString())
i += 1
Next
The following code shows how to select children of a specific node. In the example, nodes are selected via the TreeListMultiSelection.Set method of the TreeList.Selection object.
The image below shows the result of selecting a Sales and Marketing node’s children.
using DevExpress.XtraTreeList.Nodes;
TreeListNode node = treeList1.FindNodeByFieldValue("Department", "Sales and Marketing");
if (node != null) {
ArrayList selectedNodes = new ArrayList();
selectChildren(node, selectedNodes);
treeList1.Selection.Set(selectedNodes);
}
void selectChildren(TreeListNode parent, ArrayList selectedNodes) {
IEnumerator en = parent.Nodes.GetEnumerator();
TreeListNode child;
while(en.MoveNext()) {
child = (TreeListNode)en.Current;
selectedNodes.Add(child);
if(child.HasChildren) selectChildren(child, selectedNodes);
}
}
Imports DevExpress.XtraTreeList.Nodes
Dim node As TreeListNode = treeList1.FindNodeByFieldValue("Department", "Sales and Marketing")
If node IsNot Nothing Then
Dim selectedNodes As New ArrayList()
selectChildren(node, selectedNodes)
treeList1.Selection.[Set](selectedNodes)
End If
Sub SelectChildren(ByVal parent As TreeListNode, ByVal selectedNodes As ArrayList)
Dim en As IEnumerator = parent.Nodes.GetEnumerator()
Dim child As TreeListNode
While en.MoveNext() = True
child = CType(en.Current, TreeListNode)
selectedNodes.Add(child)
If child.HasChildren = True Then
selectChildren(child, selectedNodes)
End If
End While
End Sub
The following code snippet (auto-collected from DevExpress Examples) contains a reference to the Selection property.
Note
The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.
winforms-treelist-save-restore-expanded-state-of-nodes/CS/TreeListViewState.cs#L34
ArrayList al = new ArrayList();
foreach(TreeListNode node in TreeList.Selection)
al.Add(node.GetValue(TreeList.KeyFieldName));
winforms-treelist-save-restore-expanded-state-of-nodes/VB/TreeListViewState.vb#L37
Dim al As New ArrayList()
For Each node As TreeListNode In TreeList.Selection
al.Add(node.GetValue(TreeList.KeyFieldName))
See Also