vb.net 外部参照 unload 导致cad崩溃

glowz

2. <CommandMethod("AddBlockRefMenu")> _
3. Public Sub AddBlockRefMenu()
4. '定义一个ContextMenuExtension对象，用于表示快捷菜单
5. Dim contextMenu As New ContextMenuExtension()
6. '对于对象级别的快捷菜单，不必设置菜单名
7. 'contextMenu.Title = "圆的快捷菜单"
8. '添加一个名为"圆面积"的菜单项，用于在AutoCAD命令行上显示所选择的圆面积
9. Dim miBlockUnload As New MenuItem("卸载")
10. '为"圆面积"菜单项添加单击事件
11. AddHandler miBlockUnload.Click, AddressOf miBlockUnload_Click
12. '将"圆面积"菜单项添加到快捷菜单中
13. contextMenu.MenuItems.Add(miBlockUnload)
14. '为圆对象添加定义的快捷菜单
15. Application.AddObjectContextMenuExtension(RXClass.GetClass(GetType(BlockReference)), contextMenu)
16. End Sub
17. Sub miBlockUnload_Click(ByVal sender As Object, ByVal e As EventArgs)
18. Dim ed As Editor = Application.DocumentManager.MdiActiveDocument.Editor
19. Dim doc As Document = Application.DocumentManager.MdiActiveDocument
20. Dim db As Database = doc.Database
21. ' Dim bt as
22. '获取当前的选择集对象
23. Dim acObjIdColl As ObjectIdCollection = New ObjectIdCollection()
24. Dim ss As SelectionSet = ed.SelectImplied().Value
25. Using acLckDoc As DocumentLock = doc.LockDocument()
26. Using trans As Transaction = db.TransactionManager.StartTransaction()
27. '循环遍历选择集中的对象
29. For Each id As ObjectId In ss.GetObjectIds()
30. Dim obj As DBObject = trans.GetObject(id, OpenMode.ForRead)
31. '如果所选择的对象是
32. If TypeOf (obj) Is BlockReference Then
33. '获取所选择的对象
34. Dim br As BlockReference = trans.GetObject(id, OpenMode.ForRead) 'CType(obj, BlockReference)
35. Dim btr As BlockTableRecord = trans.GetObject(br.BlockTableRecord, OpenMode.ForRead)
36. If (btr.IsFromExternalReference) Then
37. Dim xrefId As ObjectId = br.BlockTableRecord
38. If (Not xrefId = ObjectId.Null) Then
39. acObjIdColl.Add(xrefId)
40. 'db.DetachXref(xrefId)
41. 'db.UnloadXrefs()
42. ' ed.WriteMessage(vbCrLf & "Xref:" & btr.Name & " Unload!")
43. End If
45. End If
46. '在命令行上显示圆面积信息
48. 'ed.WriteMessage(vbCrLf & "圆面积为:" & circ.Area.ToString())
49. End If
50. Next
51. db.UnloadXrefs(acObjIdColl)
52. trans.Commit()
53. End Using
54. End Using
55. End Sub

<CommandMethod("AddBlockRefMenu")> _ Public Sub AddBlockRefMenu() '定义一个ContextMenuExtension对象，用于表示快捷菜单 Dim contextMenu As New ContextMenuExtension() '对于对象级别的快捷菜单，不必设置菜单名 'contextMenu.Title = "圆的快捷菜单" '添加一个名为"圆面积"的菜单项，用于在AutoCAD命令行上显示所选择的圆面积 Dim miBlockUnload As New MenuItem("卸载") '为"圆面积"菜单项添加单击事件 AddHandler miBlockUnload.Click, AddressOf miBlockUnload_Click '将"圆面积"菜单项添加到快捷菜单中 contextMenu.MenuItems.Add(miBlockUnload) '为圆对象添加定义的快捷菜单 Application.AddObjectContextMenuExtension(RXClass.GetClass(GetType(BlockReference)), contextMenu) End Sub Sub miBlockUnload_Click(ByVal sender As Object, ByVal e As EventArgs) Dim ed As Editor = Application.DocumentManager.MdiActiveDocument.Editor Dim doc As Document = Application.DocumentManager.MdiActiveDocument Dim db As Database = doc.Database ' Dim bt as '获取当前的选择集对象 Dim acObjIdColl As ObjectIdCollection = New ObjectIdCollection() Dim ss As SelectionSet = ed.SelectImplied().Value Using acLckDoc As DocumentLock = doc.LockDocument() Using trans As Transaction = db.TransactionManager.StartTransaction() '循环遍历选择集中的对象 For Each id As ObjectId In ss.GetObjectIds() Dim obj As DBObject = trans.GetObject(id, OpenMode.ForRead) '如果所选择的对象是 If TypeOf (obj) Is BlockReference Then '获取所选择的对象 Dim br As BlockReference = trans.GetObject(id, OpenMode.ForRead) 'CType(obj, BlockReference) Dim btr As BlockTableRecord = trans.GetObject(br.BlockTableRecord, OpenMode.ForRead) If (btr.IsFromExternalReference) Then Dim xrefId As ObjectId = br.BlockTableRecord If (Not xrefId = ObjectId.Null) Then acObjIdColl.Add(xrefId) 'db.DetachXref(xrefId) 'db.UnloadXrefs() ' ed.WriteMessage(vbCrLf & "Xref:" & btr.Name & " Unload!") End If End If '在命令行上显示圆面积信息 'ed.WriteMessage(vbCrLf & "圆面积为:" & circ.Area.ToString()) End If Next db.UnloadXrefs(acObjIdColl) trans.Commit() End Using End Using End Sub

7.兮♂贝

做个标记，以后可能有用！