//替换CAD中原有命令为开发人员自己开发的命令的方法

        //在CAD中执行一次RegisterMyCommand命令后，再执行line时就会loadhead程序了

        [CommandMethod("RegisterMyCommand")]

        public void RegisterMyCommand()

        {

            Autodesk.AutoCAD.ApplicationServices.Application.DocumentManager.DocumentLockModeChanged += new DocumentLockModeChangedEventHandler(RedefineCommands);

        }

        private void RedefineCommands(object sender, DocumentLockModeChangedEventArgs e)

        {

            if (e.GlobalCommandName == "LINE")

            {

                e.Veto();

                LoadHead();

            }

        }