Treeview control - How to make a node blink?

Question

Hi,

Is there a "elegant" way to make blink a treeview node?

I am thinking to use a timer with the collection of nodes that I want to make the blink effect, and update the icon ...

Answer 1

Hi,

You can develop your custom control for this purpose. The logic you mentioned was correct. Here is a sample control that I developed by the logic you mentioned.

public class BlinkingTreeView : TreeView
    {
        private Timer t = new Timer();
        private List<TreeNode> blinkingNodes = new List<TreeNode>();
        public BlinkingTreeView()
        {
            t.Interval = 1000;
            t.Tick += new EventHandler(t_Tick);
        }
        bool isNodeBlinked = false;
        void t_Tick(object sender, EventArgs e)
        {
            foreach (TreeNode tn in blinkingNodes)
            {
                if (isNodeBlinked)
                {
                    //update Icon
                    tn.Text = tn.Text.Substring(0, tn.Text.Length - 1);//to test
                    isNodeBlinked = false;
                }
                else
                {
                    //update Icon
                    tn.Text = tn.Text + "*";//to test
                    isNodeBlinked = true;
                }
            }
        }
        public void AddBlinkNode(TreeNode n)
        {
            blinkingNodes.Add(n);
        }
        public void RemoveBlinkNode(TreeNode n)
        {
            blinkingNodes.Remove(n);
        }
        public void ClearBlinkNodes()
        {
            blinkingNodes.Clear();
        }
        public List<TreeNode> BlinkingNodes
        {
            get { return blinkingNodes; }
        }
        public int BlinkInterval
        {
            get { return t.Interval; }
            set { t.Interval = value; }
        }
        public void StartBlinking()
        {
            isNodeBlinked = false;
            t.Enabled = true;
        }
        public void StopBlinking()
        {
            t.Enabled = false;
        }
    }

Answer 2

Do you invalidate the window in every tick?

Answer 3

Hi,

If you need to repaint the control you can invalidate window.