wpf-402463-controls-and-libraries-navigation-controls-treeview-obtain-nodes-and-their-row-handles.md
The TreeViewControl includes multiple methods that allow you to obtain nodes and their row handles. This topic lists and describes these methods.
A row handle is an integer value that identifies a node regardless of whether it is displayed in the TreeViewControl. A visible index is an integer value that identifies only a visible node. If a node is hidden within a collapsed node, its visible index is always -1.
The following images illustrate the difference between row handles and visible indices.
All nodes are expanded:
One node is collapsed:
| Method | Description |
|---|---|
| GetNodeByContent(Object) | Returns a node with the specified content. |
| GetNodeByValue(Object) | Returns a node with the specified display value. |
| GetNodeByRowHandle(Int32) | Returns a node with the specified handle. |
| GetNodeByVisibleIndex(Int32) | Returns a node with the specified visible index. |
| CurrentNode | Gets or sets the focused node. |
| SelectedItems | Returns the collection of selected nodes. |
| API | Description |
|---|---|
| TreeListNodeBase.RowHandle | Returns a node’s row handle. |
| GetSelectedRowHandles() | Returns row handles of selected nodes. |
| GetRowHandleByVisibleIndex(Int32) | Returns a node’s row handle by its visible index. |
| GetRowVisibleIndexByHandle(Int32) | Returns a node’s position in the TreeViewControl by its row handle. |
The following code sample gets a node with the specified value, obtains the node’s row handle, and expands the specified node.
void ExpandSpecifiedNode() {
var node = treeview.GetNodeByValue("Marketing");
var rowHandle = node.RowHandle;
treeview.ExpandNode(rowHandle);
}
Private Sub ExpandSpecifiedNode()
Dim node = treeview.GetNodeByValue("Marketing")
Dim rowHandle = node.RowHandle
treeview.ExpandNode(rowHandle)
End Sub