C#

void Instance_FormClosing(object sender, FormClosingEventArgs e)
{
    if (!Disposing)
    {
        e.Cancel = true;
        Settings.Instance.Hide();
    }
}

private void COMMenuItem_Click(object sender, EventArgs e)
{
    if (Settings.Instance.Visible)
        Settings.Instance.Focus();
    else
        Settings.Instance.Show();
}

Settings formSettings;

private void COMMenuItem_Click(object sender, EventArgs e)
{
    if (formSettings == null || formSettings.IsDisposed)
        formSettings = new Settings();
    if (formSettings.Visible)
        formSettings.Focus();
    else
        formSettings.Show();
}

try
{
    setting.Activate();
}
catch
{
    setting = new Settings();
    setting.ShowDialog();
    setting.Dispose();
    setting = null;
}

Environment.GetFolderPath(Environment.SpecialFolder.System))

class MediaCenterController
    {
        private bool on;
        public bool DataSelect(byte data)
        {
            return true;
        }

        public delegate void MediaCenterHandler(object MCRunning, MediaCenterEventArg StateInfo);
        public event MediaCenterHandler MediaStateChange;
        public void MediaCenterRunning()
        {
            for (; ; )
            {
                Thread.Sleep(1000);
                bool onoff = (System.Diagnostics.Process.GetProcessesByName("calc").Length != 0);
                Debug.WriteLine(onoff);
                if (onoff != on)
                {
                    MediaCenterEventArg StateInfo = new MediaCenterEventArg(onoff);
                    if (MediaStateChange != null)
                    {
                        MediaStateChange(this, StateInfo);
                    }
                }
                on = onoff;
            }
        }
        
    }
    public class MediaCenterEventArg : EventArgs
    {
        public MediaCenterEventArg(bool on)
        {
            this.on = on;
        }
        public readonly bool on;
    }

Luc Pattyn wrote:

If your app needs to show a Form on occasion, you only have two options:
- instantiate and show the Form every time you need it;
- instantiate it once, and Show/Hide it as needed.

Luc Pattyn wrote:

that's "If it's set already, you don't need to new it up"

try
            {
                setting.Activate();
            }
            catch
            {
                setting = new Settings();
                setting.Show();
            }

setting = new Settings();
setting.showdialog(this);

yesu prakash wrote:

How can i make sure the port is secure from virus?

yesu prakash wrote:

Is there any property in socket to make itself secure from unauthorized access?