public class MyJig : DrawJig

    {

        public Point3d Point = Point3d.Origin;

        Func<JigPrompts, SamplerStatus> InputFunc;

        public List<Entity> JigEnts = new List<Entity>();

        Action<MyJig> JigUpdateAction;

        public MyJig()

        {

            JigEnts.Clear();

            InputFunc = null;

        }

        public void SetJigUpdate(Action<MyJig> action)

        {

            JigUpdateAction = action;

        }

        public void PromptInput(JigPromptPointOptions pointOpts, string msg)

        {

            InputFunc = (prmpts) =>

            {

                pointOpts.Message = msg;

                var res = prmpts.AcquirePoint(pointOpts);

                //Point就是我们要更新实体数据的点

                if (res.Value == Point)

                {

                    return SamplerStatus.NoChange;

                }

                else if (res.Value != Point)

                {

                    Point = res.Value;

                    return SamplerStatus.OK;

                }

                else

                {

                    return SamplerStatus.Cancel;

                }

            };

        }

        protected override SamplerStatus Sampler(JigPrompts prompts)

        {

            if (InputFunc == null)

            {

                return SamplerStatus.NoChange;

            }

            return InputFunc.Invoke(prompts);

        }

        protected override bool WorldDraw(WorldDraw draw)

        {

            if (JigEnts.Count > )

            {

                //这是个委托，主要实现你要如何去更新你的实体

                JigUpdateAction(this);

                foreach (var ent in JigEnts)

                {

                    ent.WorldDraw(draw);

                }

            }

            return true;

        }

        public PromptStatus Drag()

        {

            return Application.DocumentManager.MdiActiveDocument.Editor

                .Drag(this).Status;

        }

    }

public class MyDrag

    {

        Document doc = Application.DocumentManager.MdiActiveDocument;

        Editor ed = Application.DocumentManager.MdiActiveDocument.Editor;

        Database db = Application.DocumentManager.MdiActiveDocument.Database;

        Polyline pl = null;

        bool IsDrag = false;

        [CommandMethod("MyDrag")]

        public void DragIt()

        {

            IsDrag = false;

            PromptEntityOptions entOpts = new PromptEntityOptions("请选择Polyline");

            entOpts.SetRejectMessage("请选择多段线");

            entOpts.AddAllowedClass(typeof(Polyline), true);

            var pEntRes = ed.GetEntity(entOpts);

            if (pEntRes.Status != PromptStatus.OK)

                return;

            Polyline plCo = null;

            using (var trans = db.TransactionManager.StartTransaction())

            {

                pl = trans.GetObject(pEntRes.ObjectId, OpenMode.ForWrite) as Polyline;

                //这里如果不复制，直接操作pl，虽然是以写的方式打开的实体，但是会报错说NotOpenForWrite

                plCo = pl.Clone() as Polyline;

                pl.Erase();

                trans.Commit();

            }

            List<LineSegment2d> listL2d = new List<LineSegment2d>();

            for (int i = ; i < pl.NumberOfVertices - ; i++)

            {

                listL2d.Add(pl.GetLineSegment2dAt(i));

            }

            var pointRes = ed.GetPoint(new PromptPointOptions("请输入一地个点:\n"));

            if (pointRes.Status != PromptStatus.OK) return;

            Vector2d v2d = new Vector2d(, );

            JigPromptPointOptions jigOpts = new JigPromptPointOptions();

            MyJig myJig = new MyJig();

            myJig.PromptInput(jigOpts, "拖动鼠标");

            myJig.JigEnts.Add(plCo);

            int dir = -;

            myJig.SetJigUpdate((jig) =>

            {

                if (jig.JigEnts == null || jig.JigEnts.Count == )

                {

                    return;

                }

                Polyline p = jig.JigEnts[] as Polyline;

                var pt1 = pointRes.Value;

                var pt2 = jig.Point;

                var vec = pt2 - pt1;

                /*获取鼠标拖动方向，主要思路

                 *当拖动的距离拖动前按下的那个点的

                 * 距离>1的时候，计算是X轴方向还是Y轴方向

                 * 因为第一次判断，如果距离过下方向不准确。

                 * 并且这个方向一确定，就不在更改。

                 */

                if (!IsDrag)

                {

                    if (vec.Length > )

                    {

                        IsDrag = true;

                        if (Math.Abs(vec.X) > Math.Abs(vec.Y))

                        {

                            dir = ;

                        }

                        else

                        {

                            dir = ;

                        }

                    }

                }

                //向右或者向左

                if (dir == )

                {

                    v2d = new Vector2d(vec.X, );

                }

                else//向上或者向下

                {

                    v2d = new Vector2d(, vec.Y);

                }

                /*

                 * 确定要拖动的边是选择距离鼠标按下的那个点最近的边

                 */

                double minLength = double.MaxValue;

                int index = -;

                foreach (var i in Enumerable.Range(, listL2d.Count))

                {

                    var l = listL2d[i];

                    double dis = l.GetDistanceTo(new Point2d(pointRes.Value.X, pointRes.Value.Y));

                    if (dis < minLength)

                    {

                        minLength = dis;

                        index = i;

                    }

                }

                var l2d = listL2d[index];

                Matrix2d mtx2d = Matrix2d.Displacement(v2d);

                var ptGet1 = l2d.StartPoint;

                var ptGet2 = l2d.EndPoint;

                //实时得到变化的点

                var ptStart = ptGet1.TransformBy(mtx2d);

                var ptEnd = ptGet2.TransformBy(mtx2d);

                var vecGet = ptGet2 - ptGet1;

                //判断鼠标移动的方向和被拖动的边是否是在大致的同一方向

                //如果不是，就允许拖动

                if (dir ==  && (Math.Abs(vecGet.X) < Math.Abs(vecGet.Y)) ||

                dir ==  && (Math.Abs(vecGet.X) > Math.Abs(vecGet.Y)))

                {

                    p.SetPointAt(index, ptStart);

                    p.SetPointAt(index + , ptEnd);

                    //如果polyline是封闭的，要判断被拖动的点是否是闭合位置上的点，

                    //如果是，要一致更改起点和封闭点

                    if (p.Closed)

                    {

                        if (index == )

                        {

                            p.SetPointAt(p.NumberOfVertices - , ptStart);

                        }

                        if (index +  == )

                        {

                            p.SetPointAt(p.NumberOfVertices - , ptEnd);

                        }

                        if (index == p.NumberOfVertices - )

                        {

                            p.SetPointAt(, ptStart);

                        }

                        if (index +  == p.NumberOfVertices - )

                        {

                            p.SetPointAt(, ptEnd);

                        }

                    }

                }

            });

            if (myJig.Drag() != PromptStatus.OK)

            {

                return;

            }

            IsDrag = false;

            //加入到模型空间

            myJig.JigEnts.ToSpace();

            myJig.JigEnts.ForEach(a => a.Dispose());

        }

    }