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TreeNode.Expand Method

Expands the tree node.

[Visual Basic]
Public Sub Expand()
[C#]
public void Expand();
[C++]
public: void Expand();
[JScript]
public function Expand();

Remarks

The Expand method expands the current TreeNode down to the next level of nodes.

Note   The state of a TreeNode is persisted. For example, if the next level of child nodes was not collapsed previously, when the Expand method is called, the child nodes appear in their previously expanded state.

Example

[Visual Basic, C#, C++] The following example toggles the selected node when a button is clicked. If the selected node is collapsed, it is expanded, if it is expanded by calling the Expand method, it is collapsed by calling the Collapse method. This example assumes you have a Form with a TreeView control that has at least one TreeNode object with at least one child TreeNode.

[Visual Basic] 
Private Sub button1_Click(sender As Object, _
  e As System.EventArgs) Handles button1.Click
   If treeView1.SelectedNode.IsExpanded Then
      treeView1.SelectedNode.Collapse()
      MessageBox.Show(treeView1.SelectedNode.Text & _ 
        " tree node collapsed.")
   Else
      treeView1.SelectedNode.Expand()
      MessageBox.Show(treeView1.SelectedNode.Text & _
        " tree node expanded.")
   End If
End Sub 

[C#] 
private void button1_Click(object sender, System.EventArgs e)
{
   if (treeView1.SelectedNode.IsExpanded)
   {
      treeView1.SelectedNode.Collapse();
      MessageBox.Show(treeView1.SelectedNode.Text + 
        " tree node collapsed.");
   }
   else
   {
      treeView1.SelectedNode.Expand();
      MessageBox.Show(treeView1.SelectedNode.Text + 
        " tree node expanded.");
   }
}

[C++] 
private:
    void button1_Click(Object* /*sender*/, System::EventArgs* /*e*/) {
        if (treeView1->SelectedNode->IsExpanded) {
            treeView1->SelectedNode->Collapse();
            MessageBox::Show(String::Concat(treeView1->SelectedNode->Text,
                S" tree node collapsed."));
        } else {
            treeView1->SelectedNode->Expand();
            MessageBox::Show(String::Concat(treeView1->SelectedNode->Text,
                S" tree node expanded."));
        }
    }

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, .NET Compact Framework

See Also

TreeNode Class | TreeNode Members | System.Windows.Forms Namespace | ExpandAll | Collapse | IsExpanded | Toggle

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