C#

public class ParentForm : Form
    {
        private SubForm sub1;
        private SubForm sub2;

        public ParentForm()
        {
            InitializeSubForms();
        }

        private void InitializeSubForms()
        {
            sub1 = new SubForm();
            sub1.OnSelectionChanged += new SubForm.SelectionChanged(sub1_OnSelectionChanged);
            
            sub2 = new SubForm();
            sub2.OnSelectionChanged += new SubForm.SelectionChanged(sub2_OnSelectionChanged);
        }

        void sub1_OnSelectionChanged(object sender, EventArgs e)
        {
            //do sub1 eventhandling
        }

        void sub2_OnSelectionChanged(object sender, EventArgs e)
        {
            //do sub2 eventhandling
        }
    }

    public class SubForm : Form
    {
        private DataGridView dgv;

        public delegate void SelectionChanged(object sender, EventArgs e);
        public event SelectionChanged OnSelectionChanged;

        public SubForm()
        {
            dgv = new DataGridView();
            dgv.SelectionChanged += new EventHandler(dgv_SelectionChanged);
        }

        void dgv_SelectionChanged(object sender, EventArgs e)
        {
            if (OnSelectionChanged != null)
                OnSelectionChanged(sender, e);
        }
    }

private void AddEventHandler()<br />
        {<br />
            Microsoft.Win32.SystemEvents.PowerModeChanged += new Microsoft.Win32.PowerModeChangedEventHandler(PowerModeChangedSub);<br />
        }<br />
<br />
        private void PowerModeChangedSub(object sender, Microsoft.Win32.PowerModeChangedEventArgs e)<br />
        {<br />
            switch (e.Mode)<br />
            {<br />
                case Microsoft.Win32.PowerModes.Resume:<br />
                    break;<br />
                case Microsoft.Win32.PowerModes.StatusChange:<br />
                    break;<br />
                case Microsoft.Win32.PowerModes.Suspend:<br />
                    break;<br />
                default:<br />
                    break;<br />
            }<br />
        }

static class Cloner
    {
        public delegate object CloneDelegate(object o);

        private static CloneDelegate cloner;

        public static T Clone<T>(T o)
        {
            if (cloner == null)
            {
                MethodInfo info = typeof(object).GetMethod("MemberwiseClone",
                    BindingFlags.Instance | BindingFlags.NonPublic);

                cloner = (CloneDelegate)
                    Delegate.CreateDelegate(typeof(CloneDelegate), null, info);
                Debug.Assert(cloner != null);
            }

            return (T)cloner(o);
        }
    }