Topic: Get Block Details from external File

[GumbyCAD]

Hi Team,

I am trying to get the Block Details from an external file.

The external file has the blocks inserted into the file file.

The code executes but when I exit AutoCAD I get fatel error and in VS i get Memory violation error

Any ideas what I am doing wrong? Problem area is marked and if I comment it out it seams to be ok.
Many thanks in advance.

Code - Visual Basic: [Select]

1.  
2.     Private Sub GetBlockNameDetailsFromFile(ByVal FileName As String)
3.  
4.         Dim Doc As Document = Autodesk.AutoCAD.ApplicationServices.Application.DocumentManager.MdiActiveDocument
5.         Dim Ed As Editor = Doc.Editor
6.  
7.         ' create a new database
8.        Dim dwgs As Database = New Database(False, True)
9.         Dim ThisDrawingBlockCount As Integer = 0
10.  
11.         Try
12.  
13.             dwgs.ReadDwgFile(FileName, FileOpenMode.OpenForReadAndReadShare, True, "")
14.  
15.             Using Doc.LockDocument
16.  
17.                 Using trans As Transaction = dwgs.TransactionManager.StartTransaction
18.  
19.                     Dim bt As BlockTable = CType(trans.GetObject(dwgs.BlockTableId, OpenMode.ForRead, False), BlockTable)
20.  
21.                     For Each OID As ObjectId In bt
22.  
23.                         Dim btr As BlockTableRecord = CType(trans.GetObject(OID, OpenMode.ForRead, False), BlockTableRecord)
24.  
25.                         If btr.IsErased = False AndAlso btr.IsAnonymous = False Then
26.  
27.                             If Not btr.Name.ToString.StartsWith("*") Then
28.  
29.                                 Dim Col As ObjectIdCollection = btr.GetBlockReferenceIds(True, False)
30.                                 Dim eXts As Extents3d
31.                                 If Col.Count > 0 Then
32.  
33.                                     Dim Bref As BlockReference = TryCast(trans.GetObject(Col.Item(0), OpenMode.ForRead), BlockReference)
34.                                     eXts = Bref.GeometricExtents 'Save Block Extents just incase
35.  
36.                                     Dim Ans As Boolean = True
37.  
38.                                     Dim NR As DataRow = BlockDataSet.Tables("BlockDetails").NewRow
39.                                     NR.Item("FileNameIncPath") = FileName
40.                                     NR.Item("FileName") = Path.GetFileNameWithoutExtension(FileName)
41.                                     NR.Item("BlockName") = btr.Name.ToString
42.                                     NR.Item("HasAttribute") = btr.HasAttributeDefinitions
43.  
44.                                    'Problem Area - Start
45.                                    Dim Xts As Extents3d = New Extents3d
46.  
47.                                     Dim ReturnFoundData As Boolean = False
48.  
49.                                     For Each id As ObjectId In btr
50.  
51.                                         Dim Entt As Entity = DirectCast(trans.GetObject(id, OpenMode.ForRead), Entity)
52.                                        
53.                                         'Get Extents of object provided its not Text, mtext or Attribute
54.                                        If (Entt.GetRXClass.UnmanagedObject <> Autodesk.AutoCAD.Runtime.RXObject.GetClass(GetType(AttributeDefinition)).UnmanagedObject Or _
55.                                             Entt.GetRXClass.UnmanagedObject <> Autodesk.AutoCAD.Runtime.RXObject.GetClass(GetType(DBText)).UnmanagedObject Or _
56.                                             Entt.GetRXClass.UnmanagedObject <> Autodesk.AutoCAD.Runtime.RXObject.GetClass(GetType(MText)).UnmanagedObject) AndAlso _
57.                                             Entt.Bounds IsNot Nothing Then
58.  
59.                                             Xts.AddExtents(CType(Entt.Bounds, Autodesk.AutoCAD.DatabaseServices.Extents3d))
60.  
61.                                             ReturnFoundData = True
62.  
63.                                         End If
64.  
65.                                     Next
66.  
67.                                     If ReturnFoundData = False Then
68.                                         Xts = Bref.GeometricExtents
69.                                     End If
70.                                    'Problem Area - End
71.  
72.                                     NR.Item("BlockWidth") = Math.Abs(Xts.MaxPoint.X - Xts.MinPoint.X)
73.                                     NR.Item("BlockHeight") = Math.Abs(Xts.MaxPoint.Y - Xts.MinPoint.Y)
74.  
75.                                     NR.Item("PointIsInside") = Ans
76.                                     BlockDataSet.Tables("BlockDetails").Rows.Add(NR)
77.  
78.                                     ThisDrawingBlockCount += 1
79.  
80.                                 End If
81.  
82.                             End If
83.  
84.                         End If
85.  
86.                     Next
87.  
88.                     trans.Commit()
89.  
90.                 End Using
91.  
92.             End Using
93.  
94.         Catch ex As Exception
95.  
96.             Ed.WriteMessage("Error Reading " & FileName & vbCrLf & ex.Message.ToString & vbCrLf)
97.  
98.         Finally
99.  
100.             dwgs.Dispose()
101.  
102.             If ThisDrawingBlockCount = 0 Then
103.  
104.                 Dim NR As DataRow = BlockDataSet.Tables("BlockDetails").NewRow
105.                 NR.Item("FileNameIncPath") = FileName
106.                 NR.Item("FileName") = Path.GetFileNameWithoutExtension(FileName)
107.                 NR.Item("BlockName") = ""
108.                 NR.Item("HasAttribute") = False 'TODO
109.                NR.Item("BlockWidth") = 0 'TODO
110.                NR.Item("BlockHeight") = 0 'TODO
111.                NR.Item("PointIsInside") = False 'TODO
112.                BlockDataSet.Tables("BlockDetails").Rows.Add(NR)
113.  
114.             End If
115.  
116.         End Try
117.  
118.         dwgs = Nothing
119.  
120.     End Sub
121.  

[MickD]

Maybe I'm missing something but why are you getting the 'UnManagedObject' of the entity, the easiest way is just to compare the string values of the GetRXClass.Name method:


if (Entt.GetRXClass.Name <> "AcDbMText") for example.

By getting this unmanaged object you are bypassing the wrapper that handles the memory (I'm only making a wild guess here though) of the object.

[GumbyCAD]

Tryed that.......

Still getting:

AccessViolationException was Handled.
Attempted to read or write protected memory. This is often an indication that other memory is corrupt.

[WILL HATCH]

check out the dumpuserdata.xml file to see if you can get any insight


What is it you are trying to accomplish with this here?  I see you're looking at the bounds of objects within the block definition and also the extents of the first reference in the list with no regard for the transform applied to the reference.

Code - vb.net: [Select]

1.                                    'Problem Area - Start
2.                                     Dim Xts As Extents3d = New Extents3d
3.  
4.                                     Dim ReturnFoundData As Boolean = False
5.  
6.                                     For Each id As ObjectId In btr
7.  
8.                                         Dim Entt As Entity = DirectCast(trans.GetObject(id, OpenMode.ForRead), Entity)
9.  
10.                                         'Get Extents of object provided its not Text, mtext or Attribute
11.                                         If (Entt.GetRXClass.UnmanagedObject <> Autodesk.AutoCAD.Runtime.RXObject.GetClass(GetType(AttributeDefinition)).UnmanagedObject Or _
12.                                             Entt.GetRXClass.UnmanagedObject <> Autodesk.AutoCAD.Runtime.RXObject.GetClass(GetType(DBText)).UnmanagedObject Or _
13.                                             Entt.GetRXClass.UnmanagedObject <> Autodesk.AutoCAD.Runtime.RXObject.GetClass(GetType(MText)).UnmanagedObject) AndAlso _
14.                                             Entt.Bounds IsNot Nothing Then
15.  
16.                                             Xts.AddExtents(CType(Entt.Bounds, Autodesk.AutoCAD.DatabaseServices.Extents3d))
17.  
18.                                             ReturnFoundData = True
19.  
20.                                         End If
21.  
22.                                     Next
23.  
24.                                     If ReturnFoundData = False Then
25.                                         Xts = Bref.GeometricExtents
26.                                     End If
27.                                    'Problem Area - End

Then I start to get picky because I'm watching you create thousands of RXClass objects and make multiple accesses to the RXClass on each entity as you walk through the block table.

You haven't read the documentation for RXClass or you would know about using RXClass.IsDerivedFrom, since we know from the classmap that AttributeDefinition is derived from DBText the check for both can be done with a single operation mitigating the above partially.

Consider a different code structure:

Code - vb.net: [Select]

1.                                    'Problem Area - Start
2.                                     Dim Xts As Extents3d = New Extents3d
3.  
4.                                     Dim ReturnFoundData As Boolean = False
5.  
6.                                     Dim rxT as RXClass = Autodesk.AutoCAD.Runtime.RXObject.GetClass(GetType(DBText))
7.                                     Dim rxM as RXClass = Autodesk.AutoCAD.Runtime.RXObject.GetClass(GetType(MText))
8.  
9.                                     For Each id As ObjectId In btr
10.  
11.                                         Dim Entt As Entity = DirectCast(trans.GetObject(id, OpenMode.ForRead), Entity)
12.  
13.                                         Dim rxc as RXClass = Entt.GetRXClass()
14.  
15.                                         'Get Extents of object provided its not Text, mtext or Attribute
16.                                         If rxc.IsDerivedFrom(rxT) OrElse rxc.IsDerivedFrom(rxM) OrElse Entt.Bounds Is Nothing Then
17.                                             Continue For
18.                                         End If
19.                                         Xts.AddExtents(CType(Entt.Bounds, Autodesk.AutoCAD.DatabaseServices.Extents3d))
20.  
21.                                          ReturnFoundData = True
22.                                     Next
23.  
24.                                     If ReturnFoundData = False Then
25.                                         Xts = Bref.GeometricExtents
26.                                     End If
27.                                    'Problem Area - End

As to the real source of your problem... I don't think it's in this code here, this code should all easily dispose when it goes out of scope.

[nekitip]

maybe to try

Code - vb.net: [Select]

1. dwgs.ReadDwgFile(FileName, FileOpenMode.OpenForReadAndReadShare, False, Nothing)

also, maybe try Using block instead of dispose (this should not have been the issue but because of consistensy...?)

Code - vb.net: [Select]

1. Using Using db As New Database(False, True)