topic Re: Save preview to file in .NET Forum

Save preview to file

Anonymous — Sun, 12 Jun 2005 19:34:21 GMT

Hi all,

I try to save the thumbnail to a file, but it seems ThumbnailBitmap is alway's nothing. Does anyone know how to use this Autodesk.AutoCAD.DatabaseServices.Database.ThumbnailBitmap?

thanks,

Evert

----
Imports Autodesk.AutoCAD.Runtime
Imports Autodesk.AutoCAD.ApplicationServices
Imports Autodesk.AutoCAD.DatabaseServices
Imports System.Collections
Imports System.Text
Imports System.Drawing

Public Class PreviewBitMap
Public Sub test()
Dim bm As Bitmap
Dim db As Database
Try
'Get the current database
db = HostApplicationServices.WorkingDatabase
Application.DocumentManager.MdiActiveDocument.Editor.WriteMessage("db loaded")
If db.ThumbnailBitmap Is Nothing Then
Application.DocumentManager.MdiActiveDocument.Editor.WriteMessage("geen bitmap?")
Else
db.ThumbnailBitmap.Save("test.bmp")
End If
Catch ex As Exception
Application.DocumentManager.MdiActiveDocument.Editor.WriteMessage("test:" + ex.Message)
Finally
If Not bm Is Nothing Then bm.Dispose()
End Try
End Sub
End Class

Re: Save preview to file

Anonymous — Mon, 13 Jun 2005 03:49:40 GMT

You can't set a thumbnail currently. I consider this a bug so I'll make sure
we have defect logged.

albert
wrote in message news:4872660@discussion.autodesk.com...
Hi all,

I try to save the thumbnail to a file, but it seems ThumbnailBitmap is
alway's nothing. Does anyone know how to use this
Autodesk.AutoCAD.DatabaseServices.Database.ThumbnailBitmap?

thanks,

Evert

----
Imports Autodesk.AutoCAD.Runtime
Imports Autodesk.AutoCAD.ApplicationServices
Imports Autodesk.AutoCAD.DatabaseServices
Imports System.Collections
Imports System.Text
Imports System.Drawing

Public Class PreviewBitMap
Public Sub test()
Dim bm As Bitmap
Dim db As Database
Try
'Get the current database
db = HostApplicationServices.WorkingDatabase
Application.DocumentManager.MdiActiveDocument.Editor.WriteMessage("db
loaded")
If db.ThumbnailBitmap Is Nothing Then
Application.DocumentManager.MdiActiveDocument.Editor.WriteMessage("geen
bitmap?")
Else
db.ThumbnailBitmap.Save("test.bmp")
End If
Catch ex As Exception
Application.DocumentManager.MdiActiveDocument.Editor.WriteMessage("test:"
+ ex.Message)
Finally
If Not bm Is Nothing Then bm.Dispose()
End Try
End Sub
End Class

Re: Save preview to file

Anonymous — Wed, 22 Jun 2005 15:07:18 GMT

I reported this, but the thumbnail attribute has the status 'Not Implemented' (yet). It would be nice if autocad would throw an 'Not Implemented' error instead of just returning Nothing.

Re: Save preview to file

Anonymous — Wed, 22 Jun 2005 16:44:30 GMT

"Albert Szilvasy" wrote

>> You can't set a thumbnail currently. I consider this
>> a bug so I'll make sure we have defect logged.

If the objective is getting the bitmap, as opposed to
setting it, the problem is most likely this (from the
docs for AcDbDatabase::thumbnailBitmap):

"Note These APIs are meant primarily for ObjectDBX developers.
Preview thumbnail behavior reflect what the host application must
do to generate a preview.

For ObjectARX developers AutoCAD is taking care of all preview
thumbnail generation. ObjectARX users should leave these APIs
alone, and allow AutoCAD behaviors to prevail.

Most of the time, the AcDbDatabase::thumbnailBitmap() method
will return nothing, since the bitmap is not read into memory by
AcDbDatabase::readDwgFile(). To retreive the thumbnail from the
DWG file, (as opposed to directly from the db) the same existing
ObjectARX standalone functions are preferred. (for example
acdbDisplayPreviewFromDwg())".

I haven't tried this, but it should work (please let me know
if it doesn't).

/////////////////// ThumbnailExtractor.cs ///////////////////////
using System;
using System.Drawing;
using System.Runtime.InteropServices;
using Autodesk.AutoCAD.Runtime;

namespace acdbUtils
{
public class ThumbnailExtractor
{
[System.Security.SuppressUnmanagedCodeSecurity]
[DllImport("acdb16.dll", CallingConvention = CallingConvention.Cdecl,
EntryPoint = "?acdbGetPreviewBitmap@@YAPAUtagBITMAPINFO@@PBD@Z")]
extern static private IntPtr acdbGetPreviewBitmap(string filename);

static Bitmap GetBitmapFromDwg(string filename)
{
return Marshaler.BitmapInfoToBitmap(acdbGetPreviewBitmap(filename));
}
}
}

//////////////////////////////////////////////////////////////////////////////

--
http://www.caddzone.com

AcadXTabs: MDI Document Tabs for AutoCAD 2004/2005/2006
http://www.acadxtabs.com

Re: Save preview to file

Anonymous — Thu, 27 Jul 2006 06:11:52 GMT

Sir ,
As you told i tried this code but it didn't work

-----------
using System;
using System.Drawing;
using System.Runtime.InteropServices;
using Autodesk.AutoCAD.Runtime;

namespace acdbUtils
{
public class ThumbnailExtractor
{
[System.Security.SuppressUnmanagedCodeSecurity]
[DllImport("acdb16.dll", CallingConvention = CallingConvention.Cdecl,
EntryPoint = "?acdbGetPreviewBitmap@@YAPAUtagBITMAPINFO@@PBD@Z")]
extern static private IntPtr acdbGetPreviewBitmap(string filename);

static Bitmap GetBitmapFromDwg(string filename)
{
return Marshaler.BitmapInfoToBitmap(acdbGetPreviewBitmap(filename));
}
}

-----------------------

Thanks....

Re: Save preview to file

Anonymous — Thu, 31 Aug 2006 14:17:17 GMT

[code]
[System.Security.SuppressUnmanagedCodeSecurity]
[DllImport("dwgpreview.arx", CallingConvention = CallingConvention.Cdecl, CharSet = CharSet.Ansi ,
EntryPoint = "SaveDWGPreview")]
extern static private int SaveDWGPreview(string dwgfilename, string bmpfilename);

[CommandMethod("SavePreview")]
public void SavePreview()
{
Database db = HostApplicationServices.WorkingDatabase;
Autodesk.AutoCAD.Runtime.SystemObjects.DynamicLinker.LoadModule("DWGPreview.arx",false,false);
SaveDWGPreview(db.Filename,"C:\\dwgpreview.bmp");
}
[/code]

dwgpreview.arx for AutoCAD 2004...2006 is attached Message was edited by: Alexander Rivilis

Re: Save preview to file

Anonymous — Thu, 31 Aug 2006 16:10:09 GMT

For AutoCAD 2007, this should do it:

/// Form1.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.ApplicationServices;
using AcadApp = Autodesk.AutoCAD.ApplicationServices.Application;

// This form requires a PictureBox named 'pictureBox1':

namespace ThumbnailSample
{
public partial class Form1 : Form
{

public Form1()
{
InitializeComponent();
}

// R17 ONLY

[DllImport( "acad.exe", CallingConvention = CallingConvention.Cdecl,
EntryPoint = "?acedGenerateThumbnailBitmap@@YAPAUtagABITMAPINFO@@XZ" )]
private static extern IntPtr acedGenerateThumbnailBitmap();

private void ThumbView_Load( object sender, EventArgs e )
{
IntPtr bmi = acedGenerateThumbnailBitmap();
if( bmi != IntPtr.Zero )
{
Bitmap bm = Marshaler.BitmapInfoToBitmap( bmi );
pictureBox1.Image = (System.Drawing.Image) bm.Clone();
bm.Dispose();
}
}

[CommandMethod( "THUMBVIEW" )]
public static void doit()
{
using( Form1 form = new Form1() )
AcadApp.ShowModalDialog( form );
}
}
}

--
http://www.caddzone.com

AcadXTabs: MDI Document Tabs for AutoCAD 2004/2005/2006/2007
http://www.acadxtabs.com

wrote in message news:5313888@discussion.autodesk.com...
[code]
[System.Security.SuppressUnmanagedCodeSecurity]
[DllImport("dwgpreview.arx", CallingConvention = CallingConvention.Cdecl, CharSet = CharSet.Ansi ,
EntryPoint = "SaveDWGPreview")]
extern static private int SaveDWGPreview(string dwgfilename, string bmpfilename);

[CommandMethod("SavePreview")]
public void SavePreview()
{
Database db = HostApplicationServices.WorkingDatabase;
Autodesk.AutoCAD.Runtime.SystemObjects.DynamicLinker.Load
Module("DWGPreview.arx",false,false);
SaveDWGPreview(db.Filename,"C:\\dwgpreview.bmp");
}
[/code]

dwgpreview.arx for AutoCAD 2004...2006 is attached

Message was edited by: Alexander Rivilis

Re: Save preview to file

Anonymous — Sun, 03 Sep 2006 07:33:42 GMT

Sir,
Your code is working great. But i want to know does it not works for Autocad 2007 3D Drawings template(acad3D.dwt type files). If i want to save all types of autocad files's thumbanil then how can i achive this.
Thanks...

Re: Save preview to file

Anonymous — Mon, 04 Sep 2006 03:29:40 GMT

Hi rivilis,
I want to know if you have got dwgpreview.arx for Autocad 2007. IF not then how can i do it in 2007. Tony's code is working but not for 3D drawings.
Thanks....

Re: Save preview to file

Anonymous — Mon, 04 Sep 2006 09:35:59 GMT

Try it:
[code]
[System.Security.SuppressUnmanagedCodeSecurity]
[DllImport("dwgpreview.arx", CallingConvention = CallingConvention.Cdecl, CharSet = CharSet.Unicode,
EntryPoint = "SaveDWGPreview")]
extern static private int SaveDWGPreview(string dwgfilename, string bmpfilename);
[/code]

Re: Save preview to file

Anonymous — Tue, 05 Sep 2006 08:32:38 GMT

Alex's code extracts an existing preview from a .DWG file
that's been saved (with a preview), and writes it out to a
BMP file.

The code I posted doesn't do that. Instead, it generates
a new preview image of the Active viewport of the active
document, but it is not assigned as the database's saved
thumbnail.

It may also help to know that to do what Alex's code
does, you don't need native ObjectARX. You can use the
Shell's IExtractImage COM interface to get the thumbnail
preview for any file type that has one, including DWG files.

Have at look here for working example code:

http://www.vbaccelerator.com/home/net/code/libraries/Shell_Projects/Thumbnail_Extraction/article.asp

So, it depends on what you want to do (generate a new
preview, or 'snapshot' of the active viewport, or just get
the preview thumbnail from a saved file). If the drawing
is open in the editor, you should be able to save it, then
use Alex's code, or IExtractImage to get an up-to-date
thumbnail.

--
http://www.caddzone.com

AcadXTabs: MDI Document Tabs for AutoCAD 2004/2005/2006/2007
http://www.acadxtabs.com

wrote in message news:5316869@discussion.autodesk.com...
Hi rivilis,
I want to know if you have got dwgpreview.arx for Autocad 2007. IF not then how can i do it in 2007. Tony's code is working but not for 3D drawings.
Thanks....

Re: Save preview to file

Anonymous — Fri, 24 Nov 2006 07:25:14 GMT

Hello,

interesting idea to do it with a own arx.

[System.Security.SuppressUnmanagedCodeSecurity]
[DllImport("dwgpreview.arx", CallingConvention = CallingConvention.Cdecl, CharSet = CharSet.Ansi ,
EntryPoint = "SaveDWGPreview")]
extern static private int SaveDWGPreview(string dwgfilename, string bmpfilename);

My question: How is the definition of the function (dllexport) in the ARX programm.

thanks
Peter

Re: Save preview to file

Anonymous — Fri, 24 Nov 2006 11:02:17 GMT

For AutoCAD 2006:
__declspec( dllexport ) int SaveDWGPreview(const char *dwgfile, const char *bmpfile);
For AutoCAD 2007:
__declspec( dllexport ) int SaveDWGPreview(const TCHAR *dwgfile, const TCHAR *bmpfile);
Also dwgpreview.def has lines:
[code]
EXPORTS
SaveDWGPreview
[/code]

Re: Save preview to file

Anonymous — Mon, 18 Feb 2008 18:36:06 GMT

Any chance that this could be fixed to work with R2006?
I've made some modest attempts to doso, but it appears that resources like using System.Collections.Generic; are not present in 2006.

TIA

Bill

Re: Save preview to file

Anonymous — Mon, 18 Feb 2008 20:58:31 GMT

That is not an Acad error, it is a framwork issue. System.Collections.Generic isn't available until .Net 2.0.

Re: Save preview to file

Anonymous — Tue, 19 Feb 2008 02:04:00 GMT

>>>it is a framwork issue

Thanks TIm,
After I though about it a bit, I thought that probably was the case.

In any case, reading the preview image, and displaying it, is something that I think I could do. But I'd be more interested in getting the current viewport view as Tony suggested that his .cs does.
That would not only replace what we do now in Vlisp, it would be better.
In our current program, I read the block entities and draw the part, using a transformation matrix to get the VIEW ucs, then use grvecs to put it into an image_tile.
Something that I imagine would be far more complicated in C#.
Anyway, I think a view of the current viewport would do it.

TIA

Bill

Re: Save preview to file

Anonymous — Tue, 19 Feb 2008 12:02:31 GMT

>>>Anyway, I think a view of the current viewport would do it.

Hmm,
Maybe not.

I need to be able to display only the one part selected in the listbox. I've attached a .png of the DCL version.

Bill

Re: Save preview to file

Anonymous — Wed, 19 Mar 2008 14:07:11 GMT

Well I did find a way to accomplish the image problem.
Thanks to Kean Walmsley(watch word wrap):
http://through-the-interface.typepad.com/through_the_interface/2007/02/using_the_com_i.html

I learned how to acces AutoCAD geometry points of certain entities and then use those points to "paint" on a picturebox.

Thanks also to Tony T. for his PolarPoint function that enabled me to add points for arcs & circles.

I still have some scaling and rotation isues to iron out but this program duplicates what the old Vlisp one did by displaying the selected block.
I won't post the code as not all like Italian cusine but as I have time will sort things out better.

The only problem is that once in a while, some of the points that are created with PolarPoint, to duplicate arcs, don't always end up on the right plane of the arc (Using arc startangle). So that's another issue to work on (see last image in the attached).

But thanks for having this site and having people that are knowlegable in .net.
Well ack to my "day job".

Bill

Re: Save preview to file

Anonymous — Mon, 05 Mar 2012 06:37:20 GMT

HI,

I am using Auto CAD 2010 and .net

can you please tell me how i can get the preview of the dwg file using file name

Re: Save preview to file

Alfred.NESWADBA — Mon, 05 Mar 2012 07:02:51 GMT

Hi,

you have so much samples and links in the above posts. What have you tried from them? Or should all be repeated now againg?

Sorry, - alfred -