private Button mioButton;
public Button MioButton
        {
            get { return mioButton; }
            set { mioButton= value; 
                this.MioButton.Selection_Changed += new Button .SelectionChangedEventHandler(ButtonCliccato_Selection_Changed);
            }
        }
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private void ButtonCliccato_Selection_Changed(object sender, EventArgs e)
        {
            ..........................
        }