这里都是高手，请教一个简单问题？（付款20元）

yangxjn

foreach (dbx.AcadEntity Entity in _AxDbDocument.ModelSpace)
             {
              
                  switch (Entity.EntityName)
                     {
                         case "AcDbPoint":
                              dbx.AcadPoint ePoint =( dbx.AcadPoint) Entity;
                             break;
                         case "AcDbMText":
                               dbx.AcadMText eMText = (dbx.AcadMText)Entity;
                             break;
                         case "AcDbText":
                                dbx.AcadText eText = (dbx.AcadText)Entity;
                             break;
                         case "AcDbLine":
                               dbx.AcadLine eLine = (dbx.AcadLine)Entity;
                             break;
                         case "AcDbSpline":
                             dbx.AcadSpline eSpline = (dbx.AcadSpline)Entity;
                             break;
                         case "AcDbPolyline":
                               dbx.AcadLWPolyline eLPolyline = (dbx.AcadLWPolyline)Entity;
                             break;
                         case "AcDb2dPolyline":
                              ?????????????????????????????????????????????????
                             break;
                         case "AcDb3dPolyline":
                             dbx.Acad3DPolyline ePolyline = (dbx.Acad3DPolyline)Entity;
                             break;
                         case "AcDbArc":
                             dbx.AcadArc eArc = (dbx.AcadArc)Entity;
                             break;
                         case "AcDbCircle":
                              dbx.AcadCircle eCircle = (dbx.AcadCircle)Entity;
                             break;
                         case "AcDbEllipse":
                              dbx.AcadEllipse eEllipse = (dbx.AcadEllipse)Entity;
                             break;
                         case "AcDbBlockReference":
                            dbx.AcadBlockReference eBlockReference = (dbx.AcadBlockReference)Entity;
                             break;
                         default:
                            
                             break;
                     }
                 }

上面代码中如果是直线类，这可以转换成dbx.AcadLine eLine = (dbx.AcadLine)Entity;但
AcDb2dPolyline中对应的类不知道该转换成那个类？请大家帮助？？

houlinbo

AcadLWPolyline   

houlinbo

AcadPolyline