How can I make the value of a variable track the value of another

Question

Here\'s a very simplified example of what I have now:

public static class Settings
{
    public static TH th;
}

public partial class PhrasesFrame
{
    priv         


        

Answer 1

This Settings class implements a custom EventHandler (SettingsChangedEventHandler), used to notify a property change to its subscribers:
You could setup a more complex custom SettingsEventArgs to pass on different values.

Changing the public THProperty property value raises the event:

public static class Settings
{
    public delegate void SettingsChangedEventHandler(object sender, SettingsEventArgs e);
    public static event SettingsChangedEventHandler SettingsChanged;

    private static TH th;
    private static int m_Other;

    public class SettingsEventArgs : EventArgs
    {
        public SettingsEventArgs(TH m_v) => THValue = m_v;
        public TH THValue { get; private set; }
        public int Other => m_Other;
    }

    public static void OnSettingsChanged(SettingsEventArgs e) => 
        SettingsChanged?.Invoke("Settings", e);

    public static TH THProperty
    {
        get => th;
        set { th = value; OnSettingsChanged(new SettingsEventArgs(th)); }
    }
}

The PhrasesFrame class can subscribe the event as usual:

public partial class PhrasesFrame
{
    private TH id;

    public PhrasesFrame()
    {
        Settings.SettingsChanged += this.SettingsChanged;
    }

    private void SetC1Btn()
    {
        var a = (int)this.id;
        //Other operations
    }

    private void SettingsChanged(object sender, Settings.SettingsEventArgs e)
    {
        this.id = e.THValue;
        SetC1Btn();
    }
}