Treeview control in SharePoint - doesn't refresh when I update web part properties

I'm trying to create a web part that contains a TreeView control. I've got a Web Part bool property called MyCheckbox and I use this to determine which nodes should appear in the Treeview.

The problem I'm having is that when I modify the property exposed in the Web Part Properties ("Modify Shared Web Part.."), the MyCheckBox bool, and hit 'OK', the Treeview doesn't refresh. However, if I then browse to the page, the treeview is updated.

I am declaring the class as follows, using the Treeview and its root node as member variables:

public class MyWebPart : System.Web.UI.WebControls.WebParts.WebPart
{
    private TreeView tree = new TreeView();
    private TreeNode rootNode; 

    [WebBr开发者_StackOverflow中文版owsable(true)]    
    [Personalizable(PersonalizationScope.Shared)]
    public bool MyCheckBox
    {
        get { return _myCheckBox; }
        set { _myCheckBox = value; } 
    }

    private bool __myCheckBox = false;


    public MyWebPart()
    {
    }

    public override void RenderControl(HtmlTextWriter writer)
    {
        tree.RenderControl(writer);
    }

    protected override void CreateChildControls()
    {
        rootNode = new TreeNode("ExampleRootNode");

        for ( int x = 0; x < 3; x++) 
        {
            TreeNode listNode = new TreeNode(x.ToString());
            rootNode.ChildNodes.Add(listNode);
        }

        if (_myCheckBox) 
        { 
            TreeNode listNode = new TreeNode("Final entry");
            rootNode.ChildNodes.Add(listNode);
        }

        tree.Nodes.Add(rootNode);
        this.Controls.Add(tree);           
    }

    protected override void Render(HtmlTextWriter writer)
    {           
        base.Render(writer);
    }
}

I've tried checking postback, clearing the list, and a million other things. I'm sure I must be missing something!

This is due to the page / control lifecycle of ASP.NET. The writing of properties from the editorpart (the browsable property basically has an on the fly editorpart section created) to the webpart occurs at a later stage than when the CreateChildCOntrols of the webpart is called, namely at the processing of postback events.

As a reference, see this image: