How can I prevent from remove graphics drew on picturebox?

Question

I'm writing dijkstra algorithm,i don't know how can I prevent from remove graphics drew on picturebox,i put a little bit code in here.in addition,i put picture for understand better.but as you see in the picture,part of circle picture is removed that's why i drag windows form.

   private List<Node> listNode = new List<Node>();
   private int counter = 0;
    private void DrawCircles(int nodeId)
    {
        Graphics g = picBoard.CreateGraphics();
        g.SmoothingMode = SmoothingMode.AntiAlias;
        Rectangle rect = new Rectangle(listNode[nodeId].Location.X - 12, listNode[nodeId].Location.Y - 12, 25, 25);
        Pen myPen = new Pen(Brushes.Black, 2);
        g.FillEllipse((listNode[nodeId].Selected ? listNode[nodeId].SelectedColor
            : listNode[nodeId].NormalColor), rect);
        g.DrawEllipse(myPen, rect);
        TextRenderer.DrawText(g, nodeId.ToString(), new Font("Tahoma", 8),
            rect, Color.Black,
            TextFormatFlags.VerticalCenter | TextFormatFlags.HorizontalCenter);

        g.Dispose();
    }

    private void picBoard_MouseDoubleClick(object sender, MouseEventArgs e)
    {
        if (e.Button == MouseButtons.Left)
        {
            Node node = new Node(counter, e.Location);
            listNode.Add(node);
            DrawCircles(counter);
            counter++;

            InitializeNodeList();
        }
    }

I founded another way

i put this code in DrawCircle() method this code cause no longer remove circle graphics on picturebox but this code has a problem that each time doubleClick remove before node.

       private void DrawCircles(int nodeId)
    {
         Bitmap bmp = new Bitmap(picBoard.Width, picBoard.Height);
        Graphics g = Graphics.FromImage(bmp);
        g.SmoothingMode = SmoothingMode.AntiAlias;
        Rectangle rect = new Rectangle(listNode[nodeId].Location.X - 12, listNode[nodeId].Location.Y - 12, 25, 25);
        Pen myPen = new Pen(Brushes.Black, 2);
        g.FillEllipse((listNode[nodeId].Selected ? listNode[nodeId].SelectedColor
            : listNode[nodeId].NormalColor), rect);
        g.DrawEllipse(myPen, rect);
        TextRenderer.DrawText(g, nodeId.ToString(), new Font("Tahoma", 8),
            rect, Color.Black,
            TextFormatFlags.VerticalCenter | TextFormatFlags.HorizontalCenter);
        picBoard.Image = bmp;
    }
   private void picBoard_MouseDoubleClick(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left)
    {
        Node node = new Node(counter, e.Location);
        listNode.Add(node);
        DrawCircles(counter);
        counter++;

        InitializeNodeList();
    }
}
    private void InitializeNodeList()
    {
        cmbFromNode.Items.Clear();
        CmbToNode.Items.Clear();
        foreach (var node in listNode)
        {
            cmbFromNode.Items.Add(node.Id);
            CmbToNode.Items.Add(node.Id);
            // cmbWeight.Items.Add()
        }
    }