Add uncheck all checkbox for TreeView

Question

I have a TreeView with a checkbox in for each node. I also have one checkbox outside of the tree which, when clicked needs to uncheck all of the checkboxes inside of the tree.

How can I do that?

Answer 1

Try

protected void CheckBox1_CheckedChanged(object sender, EventArgs e)
{
    //if checkbox is unchecked
    if (!CheckBox1.Checked)
    {
        //uncheck all checkboxes of tree view
        foreach (TreeNode node in TreeView.Nodes)
        {
            node.Checked = false;
        }
    }
}

Add an event handler on the checkbox outside the panel

<asp:CheckBox id="CheckBox1" runat="server" OnCheckedChanged="CheckBox1_CheckedChanged" />

Answer 2

Use recursion to iterate the hole treeview and set the checked-property to true

private void Node(TreeNode root)
{
   root.Checked = true;

   foreach (TreeNode childNode in root.Nodes)
   {     
      childNode.Checked = true;

      Node(childNode);
   }
}