Open PDF for ActiveX-Viewer from stream instead of file

[EdWin1409]

Hi,
is it possible to open a pdf from a memory-stream instead of a file on disk drive ?
Background : I use your components as a frontend to a large DMS. The DMS returns the documents as memory streams, so I have to save the stream to a file and reopen it via activeX-control. This is no good practice for two reasons. First, unnecessary i/o operations and second, security reasons. I would not give the end user the possibility to get a 'real' pdf file. If I could use only memory streams, it`s much harder to get the pdf data.
I use C# with .net Framework 3.5

Thanks,

Jürgen

[John - Tracker Supp]

Hi,

this is not currently possible - however we hope to add this ability in the next release in approx 20-14 days time

[KennethAa]

Hi,

Am I just missing something here, or was this feature not included in build 38?

It's mentioned in the end user viewer history: https://www.pdf-xchange.com/home/pr ... r/history/

But I can't find any support for this in the interface definitions..

With regards,
Kenneth

[Ivan - Tracker Software]

Please see documentaion for Named operations: OpenDocument and SaveDocument.

[KennethAa]

I did, and have rechecked.

And as far as I can see, both in the documentation and in idl viewed with oleview, there is no support for loading/saving with a memory array or the IStream COM interface.

Are we talking about different things here?

With regards,
Kenneth

[John - Tracker Supp]

Hi Kenneth,

my colleague was unaware that the SDK Doc's are still in progress for build 38, though we have released the ActiveX - these will be available tomorrow AM.

In the meantime - please see attached which are not fully proof read/corrected.

Hope that helps

[KennethAa]

Got the hint I needed, thanks!

Kenneth

[John - Tracker Supp]

Pleasure

[EdWin1409]

Nice to see that the open and save funcs now support streams.
Will try it out immediately. Many thanks guys, great work

Juergen

[John - Tracker Supp]

Pleasure Juergen

[Dorwol]

Please can you give me a little sample-code for VB6 OR a link to any documentation about this feature?

I dont understand how to load or save it to a stream/array.

In help-PDF (on page 30 or page 95) I found "save to disc" only...!

[Dorwol]

Any way to do this?

[John - Tracker Supp]

Hi,

Here is the updated Manual - please see indexed page 34 (39 of the physical file)

HTH

[Dorwol]

Sorry, but I do not succeed.

I do not manage to submit the IStream to and from a ADO-Data-Object.

And also I do not find any documentation of Eduardo's-"STRM.tlb"-Typelibrary. So I dont know how to put the content of "VBStrm.IStream" to "ADODB.Stream"...!?

What I want is to save/load the PDF to and from a sql-database (blob-/image-object of SQL-Server).

PLEASE, is it possible to give me a little sample-code in VB6?

Very big thanks!

[Corwin - Tracker Sup]

Sorry, but I'm not familiar with "ADODB.Stream" and can't check projects which uses ADO-Data-Object here.
Have you tried to use ADODB.Stream instead of VBStrm.IStream? Any luck with that?
Anyway, you can always save ADODB.Stream object to file on disk and then load it directly to ViewerAx.

[Dorwol]

Have you tried to use ADODB.Stream instead of VBStrm.IStream? Any luck with that?

Yes, no luck! ;-(

Anyway, you can always save ADODB.Stream object to file on disk and then load it directly to ViewerAx.

Yes, I know. That's the way I go at this time (but I don't want the detour to HDD!)

[Corwin - Tracker Sup]

I'm thinking that there must be a way to get/set binary data (array of bytes) from ADODB.Stream. This array can be used to create standard IStream.

[Dorwol]

I'm thinking that there must be a way to get/set binary data (array of bytes) from ADODB.Stream.

Yes, that is correct...and I know this way!

This array can be used to create standard IStream.

Yes, I agree with you - but the question is "how"?

[Vasyl - PDF-XChange]

Possible solution for you:

Open document:
1. Create empty, memory-IStream object by CreateStreamOnHGlobal(NULL, TRUE, StreamOut);
2. Load binary data from ADODB.Stream into this memory-IStream.
3. Pass filled IStream-object to our 'OpenDocument' routine.

Save document:
1. Create empty, memory-IStream object by CreateStreamOnHGlobal(NULL, TRUE, StreamOut);
2. Pass this IStream-object to our 'SaveDocument(DocID)' routine.
3. Copy all content from this IStream-object to ADODB.Stream

[Corwin - Tracker Sup]

but the question is "how"?

Try to use this procedure:

Code: Select all

Private Declare Function CreateStreamOnHGlobal Lib "ole32" (ByVal hGlobal As Long, ByVal fDeleteOnRelease As Long, ppstm As Any) As Long
.........
Public Sub BytesToStream(b() As Byte)
	Dim LowerBound As Long
	Dim ByteCount As Long
	Dim hMem As Long
	Dim lpMem As Long
	Dim istm As VBStrm.IStream
	
	On Error GoTo Err_Lbl
	If UBound(b, 1) < 0 Then
		Exit Sub
	End If
	
	LowerBound = LBound(b)
	ByteCount = (UBound(b) - LowerBound) + 1
	hMem = GlobalAlloc(&H2, ByteCount)
	If hMem <> 0 Then
		lpMem = GlobalLock(hMem)
		If lpMem <> 0 Then
			CopyMemory ByVal lpMem, b(LowerBound), ByteCount
			Call GlobalUnlock(hMem)
			If CreateStreamOnHGlobal(hMem, 1, istm) = 0 Then
				...........
			End If
		End If
	End If
	Exit Sub
	Err_Lbl:
	MsgBox "Error"
End Sub

[Dorwol]

Thx, will try it!

[Dorwol]

Corwin, U are my HERO!

THANK YOU VERY VERY MUCH!
It WORKS FANTASTIC!

A question is still left now. How does the reversed way go? (I mean "StreamToBytes")...

If you should still have a tip for it for me, this would be wonderful. If not, you are nevertheless my hero!

[Corwin - Tracker Sup]

Nice to know, that previous solution helped you

VBStrm.IStream has methods Stat(where you can get size of stream) and Read(to get bytes from stream). You can try to use these methods to get bytes array from IStream.
For more information of how to use IStream you can read at msdn.

[Dorwol]

Great, this will help me!