Hi nvx,

The only way it appears you can catch the user deleting the content is by
inheriting NumericUpDown and override for instance the Text property

   public class MyNumeric : NumericUpDown
   {
       public override string Text
       {
           get
           {
               if (base.Text == "")
                   base.Text = Minimum.ToString();
               
               return base.Text;
           }
           set
           {
               base.Text = value;
           }
       }
   }

Interestingly, the setter will never get notified of the empty string so you
need to catch it in the getter.