Hook？

 public interface IHook

    {

        /// <summary>

        /// 二维地图控件对象

        /// </summary>

        ESRI.ArcGIS.Controls.IMapControl4 MapControl { get; set; }



     }

 public class HookHelper: IHook

    {

        private static HookHelper mHookHelper = null;



        private HookHelper() { }



        public static HookHelper GetInstance()

        {

            if (mHookHelper == null)

            {

                mHookHelper = new HookHelper();

            }



            return HookHelper;

        }



        public IEventAggregator EventAggregator { get; set; }



        public ESRI.ArcGIS.Controls.IMapControl4 MapControl { get; set; }



        public ESRI.ArcGIS.Carto.IMap Map { get; set; }

}

从一个黑箱中有引n条线。