TreeNodeCollection.Insert Method (Int32, TreeNode)


Inserts an existing tree node into the tree node collection at the specified location.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

public virtual void Insert(
	int index,
	TreeNode node


Type: System.Int32

The indexed location within the collection to insert the tree node.

Type: System.Windows.Forms.TreeNode

The TreeNode to insert into the collection.

Exception Condition

The node is currently assigned to another TreeView.

If the TreeView.Sorted property is set to true, the index parameter value is ignored. The TreeNode is inserted into the tree view, and the TreeView resorted.

You can also add new TreeNode objects to the collection by using the Add or AddRange methods.

To remove a TreeNode that you previously added, use the Remove, RemoveAt, or Clear methods.


A TreeNode can be assigned to only one TreeView control at a time. To add the tree node to a new tree view control, you must remove it from the other tree view first or clone it.

The following code example removes the selected tree node from one TreeView and adds it to another if both tree node collections are not read-only. When a Button is clicked, the TreeNode represented by the TreeView.SelectedNode property is deleted from one TreeView using the Remove method and added to the other TreeView using the Insert method. This example requires that you have a Form that contains two TreeView controls and a Button. The TreeView controls should be named treeView1 and treeView2.

private void button1_Click(object sender, EventArgs e)
   // If neither TreeNodeCollection is read-only, move the 
   // selected node from treeView1 to treeView2.
   if(!treeView1.Nodes.IsReadOnly && !treeView2.Nodes.IsReadOnly)
      if(treeView1.SelectedNode != null)
         TreeNode tn = treeView1.SelectedNode;
         treeView2.Nodes.Insert(treeView2.Nodes.Count, tn);

.NET Framework
Available since 1.1
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