Topic: BlockPreview in PictureBox

[mgreven]

Hello,

I am trying to show a Preview of a block in a form using a picturebox.

I have a listbox containing the blocknames of the active drawing, and show a preview of the selected block in a Picturebox using de Blockrecord.PreviewIcon.
But the quality of the preview is bad. How can i get a preview like the one in the "Block Edit" Form, or like the "Object Viewer" in AutoCAD?


         


Can someone help me with this?

[mgreven]

I have made a routine which makes a snapshot of a block and saves this to a file, this file i can use in the picturebox.
But there must be a better and quicker way to do it.

Here is my code:

Code - vb.net: [Select]

1. Public Function GetSnapshot(Blockname As String) As Bitmap
2.         Dim doc As Document = Application.DocumentManager.MdiActiveDocument
3.         Dim ed As Editor = doc.Editor
4.         Dim db As Database = doc.Database
5.         Dim gsm As Manager = doc.GraphicsManager
6.         Dim screenSize As Size = New Size(My.Computer.Screen.Bounds.Width, My.Computer.Screen.Bounds.Height)
7.         Dim MyBitmap As New System.Drawing.Bitmap(My.Computer.Screen.Bounds.Width, My.Computer.Screen.Bounds.Height, Imaging.PixelFormat.Format32bppPArgb)
8.         MyBitmap.SetResolution(200, 200)
9.         ' Get some AutoCAD system variables
10.         Dim vpn As Integer = System.Convert.ToInt32(Application.GetSystemVariable("CVPORT"))
11.         ' Get AutoCAD's GS view for this document...
12.         Dim gsv As View = doc.GraphicsManager.GetGsView(vpn, True)
13.  
14.  
15.         ' ... but create a new one for the actual snapshot
16.         Using view As New View()
17.             ' Set the view to be just like the one
18.             ' in the AutoCAD editor
19.             view.Viewport = gsv.Viewport
20.             view.SetView(gsv.Position, gsv.Target, gsv.UpVector, gsv.FieldWidth, gsv.FieldHeight)
21.             view.EraseAll()
22.             ' Set the visual style to the one passed in
23.             view.VisualStyle = New VisualStyle(VisualStyleType.Wireframe2D)
24.             Dim dev As Device = gsm.CreateAutoCADOffScreenDevice()
25.             Using dev
26.                 dev.OnSize(gsm.DisplaySize)
27.                 ' Set the render type and the background color
28.                 dev.DeviceRenderType = RendererType.[Default]
29.                 dev.BackgroundColor = Color.Black
30.                 ' Add the view to the device and update it
31.                 dev.Add(view)
32.                 dev.Update()
33.                 Using model As Model = gsm.CreateAutoCADModel()
34.                     Dim tr As Transaction = db.TransactionManager.StartTransaction()
35.                     Dim BlkRefID As ObjectId
36.                     Using tr
37.                         ' Add the modelspace to the view
38.                         ' It's a container but also a drawable
39.                         Dim bt As BlockTable = DirectCast(tr.GetObject(db.BlockTableId, OpenMode.ForRead), BlockTable)
40.                         ''Dim btr As BlockTableRecord = DirectCast(tr.GetObject(bt("R-12000-7250 A U is 0"), OpenMode.ForRead), BlockTableRecord)
41.                         Dim btr As BlockTableRecord = DirectCast(tr.GetObject(bt(BlockTableRecord.ModelSpace), OpenMode.ForRead), BlockTableRecord)
42.                         If bt.Has(Blockname) Then
43.                             ''Dim dummy As ObjectId = InsertBlock(db, "ModelSpace", New Point3d(0, 0, 0), Blockname, 1, 1, 1, 0)
44.                             BlkRefID = InsertBlock(db, "ModelSpace", New Point3d(0, 0, 0), Blockname, 1, 1, 1, 0)
45.                         End If
46.  
47.                         view.Add(btr, model)
48.                         tr.Commit()
49.  
50.                        
51.  
52.                        
53.                     End Using
54.                     ''Dim acadApp As Object = Application.AcadApplication
55.                     ''acadApp.ZoomExtents(New Point3d(0, 0, 0), New Point3d(7500, 13000, 0))
56.                     view.ZoomExtents(New Point3d(0, 0, 0), New Point3d(7500, 13000, 0))
57.                     ' Take the snapshot
58.                     Dim rect As Rectangle = view.Viewport
59.  
60.                     Using bitmap As Bitmap = view.GetSnapshot(rect)
61.                         MyBitmap = bitmap
62.  
63.                         bitmap.Save("c:\temp\" & Blockname & ".png")
64.  
65.                         ''MyBitmap = bitmap
66.                         ''bitmap.Save(filename)
67.                         ''ed.WriteMessage(vbLf & "Snapshot image saved to: " & filename)
68.                         ' Clean up
69.                         ''view.EraseAll()
70.                         dev.[Erase](view)
71.                         ''Return bitmap
72.                     End Using
73.  
74.                     Dim Mytr As Transaction = db.TransactionManager.StartTransaction()
75.                     Using Mytr
76.  
77.                         Dim bt As BlockTable = DirectCast(Mytr.GetObject(db.BlockTableId, OpenMode.ForWrite), BlockTable)
78.                         Dim btr As BlockTableRecord = DirectCast(Mytr.GetObject(bt(BlockTableRecord.ModelSpace), OpenMode.ForWrite), BlockTableRecord)
79.  
80.                         Dim MyBlockRef As AcadDb.BlockReference = Mytr.GetObject(BlkRefID, OpenMode.ForWrite)
81.                         MyBlockRef.Erase()
82.                         Mytr.Commit()
83.  
84.                     End Using
85.                 End Using
86.  
87.             End Using
88.             view.Dispose()
89.         End Using
90.  
91.         Return MyBitmap
92.  
93.     End Function
94.  
95.