Question

Basically, this is what happens. I have a thread(endless loop) that runs as a background process while the form is showing. The thread checks if there is a need to add a new ToolStripMenuItem.

If the conditions are met, I’ll need to use Invoke in order to create the UI object right? Problem with this is, when the this.Invoke or BeginInvoke is called, the form became unresponsive while the thread that does the checking is still running fine. Any ideas?

This is the first time i’m trying with this multithreading thingee. I’m sure i’ve missed out something.

 public void ThreadSetCom()
    {
        while (true)
        {
            string[] tmpStrPort = System.IO.Ports.SerialPort.GetPortNames();
            IEnumerable<string> diff = tmpStrPort.Except(strPort);
            strPort = tmpStrPort;
            System.Console.WriteLine(System.IO.Ports.SerialPort.GetPortNames().Length);
            foreach (string p in diff)
            {
                var cpDropdown = (ToolStripMenuItem)msMenu.Items["connectToolStripMenuItem"];
                cpDropdown = (ToolStripMenuItem)cpDropdown.DropDownItems["connectReaderToolStripMenuItem"];

                ToolStripMenuItem tsmi = new ToolStripMenuItem();
                tsmi.Text = p;
                tsmi.Name = p;
                tsmi.Click += new EventHandler(itm_Click);

                if (this.msMenu.InvokeRequired)
                {
                    GUIUpdate d = new GUIUpdate(ThreadSetCom);
                    this.Invoke(d);
                }
                else
                {
                    cpDropdownList.DropDownItems.Add(tsmi);
                }                
            }                
        }
    }

Answer 1

Your ThreadSetCom method never exits:

while (true)

… with no return or break statements. That’s going to hang the UI thread forever.

It’s not clear what you’re trying to achieve, but you definitely don’t want to be looping like that in the UI thread. I’d argue that you don’t want to be looping like that in a tight way in any thread, mind you…