UIDocument uidoc=commandData.Application.ActiveUIDocument;

            Document doc=uidoc.Document;

            Material material=new FilteredElementCollector(doc).OfClass(typeof(Material)).Cast().First() as Material;

            Reference refer = commandData.Application.ActiveUIDocument.Selection.PickObject(ObjectType.Element);

            Wall wall = doc.GetElement(refer) as Wall;

            CompoundStructure cs = wall.WallType.GetCompoundStructure();

            Transaction ts = new Transaction(doc,"BIM");

            ts.Start();

            CompoundStructureLayer layer = new CompoundStructureLayer(300/304.8,MaterialFunctionAssignment.Structure,material.Id);

            CompoundStructureLayer layer1 = new CompoundStructureLayer(200/304.8, MaterialFunctionAssignment.Structure, material.Id);

            CompoundStructureLayer layer2 = new CompoundStructureLayer(100/304.8, MaterialFunctionAssignment.Structure, material.Id);

            IList list = new List() { layer,layer1,layer2};

            cs.SetLayers(list);

            wall.WallType.SetCompoundStructure(cs);

            ts.Commit();

 //材質 厚度，資訊互換

 //非目標牆

            //Reference refer1 = commandData.Application.ActiveUIDocument.Selection.PickObject(ObjectType.Element);

            //Wall wall1 = commandData.Application.ActiveUIDocument.Document.GetElement(refer1) as Wall;

            //Transaction ts = new Transaction(commandData.Application.ActiveUIDocument.Document, "BIM");

            //ts.Start();

            //CompoundStructure cs1 = wall1.WallType.GetCompoundStructure();

            //ElementId materialId = null;

            //double width = 0;

            //foreach (CompoundStructureLayer layer in cs1.GetLayers())

            //{

            //    if (layer.Function == MaterialFunctionAssignment.Structure)

            //    {

            //        materialId = layer.MaterialId;

            //        layer.Width = 300 / 304.8;

            //        width = layer.Width;

            //        break;

            //    }

            //}

            //CompoundStructure cs = wall.WallType.GetCompoundStructure();

            //MessageBox.Show((doc.GetElement(materialId) as Material).Name);

            //CompoundStructureLayer newlayer = null;

            //foreach (CompoundStructureLayer layer in cs.GetLayers())

            //{

            //    if (layer.Function == MaterialFunctionAssignment.Structure)

            //    {

            //        layer.MaterialId = (doc.GetElement(materialId) as Material).Id;

            //        layer.Width = width;

            //        cs.SetMaterialId(layer.LayerId,materialId);

            //        cs.SetLayerWidth(layer.LayerId,width);

            //        newlayer = layer;

            //        break;

            //    }

            //}

            //wall.WallType.SetCompoundStructure(cs);

            //ts.Commit();

           // CompoundStructure cs3 = wall2.WallType.GetCompoundStructure();

           // wall.WallType.SetCompoundStructure(cs3);