<CommandMethod("Test")> _
Public Sub RotatedDimension()
    Dim doc As Document = Application.DocumentManager.MdiActiveDocument
    Dim db As Database = doc.Database
    Dim idDim As ObjectId = ObjectId.Null
    Dim Ent As Entity
    Dim x As Double
    Using myTrans As Transaction = db.TransactionManager.StartTransaction()
        Dim bt As BlockTable = myTrans.GetObject(db.BlockTableId, OpenMode.ForRead)
        Dim btr As BlockTableRecord = myTrans.GetObject(bt(BlockTableRecord.ModelSpace), OpenMode.ForWrite)
        ''выбираем существующий размер
        '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
        Dim ss As Autodesk.AutoCAD.EditorInput.SelectionSet = doc.Editor.GetSelection().Value
        For Each id As ObjectId In ss.GetObjectIds()
            Ent = myTrans.GetObject(id, OpenMode.ForRead, True)
            If TypeOf Ent Is RotatedDimension Then
                x = Ent.Bounds.Value.MinPoint.X  ''''' обращаемся к свойству Bounds - работает прекрасно
            End If
        Next id
        ''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
        '' создаем размер
        ''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
        Dim RotDim As RotatedDimension = New RotatedDimension()
 
        RotDim.SetDatabaseDefaults(db)
        RotDim.DimensionStyle = db.Dimstyle
 
 
        RotDim.XLine1Point = New Point3d(0, 0, 0)
        RotDim.XLine2Point = New Point3d(50, 0, 0)
        RotDim.Rotation = 0
        RotDim.DimLinePoint = New Point3d(25, 10, 0)
 
        idDim = btr.AppendEntity(RotDim)
        myTrans.AddNewlyCreatedDBObject(RotDim, True)
 
        'x = RotDim.Bounds.Value.MinPoint.X  ''''' обращаемся к свойству Bounds - не работает 
        ''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
        myTrans.Commit()
    End Using
    ' В другой транзакции получаем габариты размеров
    Using myTrans As Transaction = db.TransactionManager.StartTransaction()
        Ent = myTrans.GetObject(idDim, OpenMode.ForRead, True)
        Dim x1 As Double = Ent.Bounds.Value.MinPoint.X
        Dim x2 As Double = Ent.Bounds.Value.MaxPoint.X
        myTrans.Commit()
    End Using
End Sub