Context menu does not open on first click

I have a C# application where I dynamically populate, then launch开发者_Go百科 a context menu called cmTestplan.

    private void cmTestplan_Opening(object sender, CancelEventArgs e)
    {
        if ((cmTestplan.SourceControl is TextBox) && 
        (cmTestplan.SourceControl.Enabled == true) && 
        (cmTestplan.SourceControl.Text != ""))
        {

            RightClickSetup(cmTestplan.SourceControl.Text);
            cmTestplan.Show();
        }

    }

    private void RightClickSetup(string Path)
    {
        this.UseWaitCursor = true;
        cmTestplan.Items.Clear();

        //Test for file or folder
        if (Directory.Exists(Path) == true)
        {
            cmTestplan.Items.Add("Open folder");
            this.UseWaitCursor = false;
        }
        else if (File.Exists(Path) == true)
        {
            cmTestplan.Items.Add("Open folder");
            cmTestplan.Items.Add("Open file");
            this.UseWaitCursor = false;
        }
    }

For some reason (that I hope one of you fine ladies or gentlemen may be able to provide) the menu does not display on the first time I right-click on a text box with which this cmTestplan is associated. It will display consistently thereafter on a single right-click.

I've tried commenting out all the file/folder checking and still get the problem.

Your menu does not open since the event argument cancel is default true for an empty menu.

simply add e.Cancel = false; in your Opening event handler;

   RightClickSetup(cmTestplan.SourceControl.Text);
   e.Cancel = false;

.. you can also skip the "show" call.

See also MSDN