Debenu Quick PDF Library - PDF SDK Community Forum : AddImageFromString

Debenu Quick PDF Library - PDF SDK Community Forum : AddImageFromString http://www.quickpdf.org/forum/ Copyright (c) 2006-2013 Web Wiz Forums - All Rights Reserved. Thu, 14 May 2026 16:51:22 +0000 Sat, 31 Jul 2021 15:14:09 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 11.01 360 www.quickpdf.org/forum/RSS_post_feed.asp?TID=3942 <![CDATA[Debenu Quick PDF Library - PDF SDK Community Forum]]> http://www.quickpdf.org/forum/forum_images/QPDF_Forum_Title.png http://www.quickpdf.org/forum/ <![CDATA[AddImageFromString : From my opinion opening an image...]]> http://www.quickpdf.org/forum/addimagefromstring_topic3942_post15849.html#15849 Author: Ingo
Subject: 3942
Posted: 31 Jul 21 at 3:14PM

From my opinion opening an image with notepad should give me the same view than look directly into your string content. Are there differences?
BTW: There's another function called AddImageFromStream available...

]]> Sat, 31 Jul 2021 15:14:09 +0000 http://www.quickpdf.org/forum/addimagefromstring_topic3942_post15849.html#15849 <![CDATA[AddImageFromString : The links that Ingo posted confirm...]]> http://www.quickpdf.org/forum/addimagefromstring_topic3942_post15848.html#15848 Author: tfrost
Subject: 3942
Posted: 30 Jul 21 at 9:08PM

The links that Ingo posted confirm my feeling that the problem is much more likely to arise in preparing the 'string', and not in QPDF itself. The key to passing the data to QPDF is never to treat it as a 'string'. It is just a block of bytes. If you ever give the compiler a chance to treat it as a string, C or C++ functions will stop processing at the first null byte (and there are many of these in an image). So my feeling is that if you really 'read a string from the table' you will end up with only a tiny piece of it; the rest will have disappeared already, before you even try to pass it to QPDF. You should treat it always as an array of bytes, and only use 'string' when you cast the pointer to pass to QPDF. But I never use C with QPDF, so do not have personal experience of this problem!]]> Fri, 30 Jul 2021 21:08:13 +0000 http://www.quickpdf.org/forum/addimagefromstring_topic3942_post15848.html#15848 <![CDATA[AddImageFromString : Hi,I jump into this thread for...]]> http://www.quickpdf.org/forum/addimagefromstring_topic3942_post15847.html#15847 Author: JanX
Subject: 3942
Posted: 30 Jul 21 at 7:51PM

Hi,

I jump into this thread for I face the same problem as Edgar. And I tried LastErrorCode() as suggested, but that also returns a 0.

The point is: AddImageFromFile() works like a charme. But what I do (please don't discuss this) is that the picture is stored in a binary table field. The character set of this table is ANSI. When creating the PDF file I read the string from the table. And I want to add this string to the pdf without the detour storing this string to a temp file and adding this to the PDF via AddImageFromFile().

So: When AddImageFromFile() (and all other function calls I do) is working, but AddImageFromString() and LastErrorCode() both return a 0 - what's wrong?

JanX

]]> Fri, 30 Jul 2021 19:51:24 +0000 http://www.quickpdf.org/forum/addimagefromstring_topic3942_post15847.html#15847 <![CDATA[AddImageFromString : These three threads will give...]]> http://www.quickpdf.org/forum/addimagefromstring_topic3942_post15844.html#15844 Author: Ingo
Subject: 3942
Posted: 26 Jul 21 at 10:11PM

These three threads will give you an idea how to do it the right way:
http://www.quickpdf.org/forum/c-using-addimagefromstring-with-drawingimaging_topic2308.html
http://www.quickpdf.org/forum/addimagefromstring-in-c-dll-project-resolved_topic2144.html
https://www.debenu.com/kb/how-do-i-programmatically-create-thumbnails-for-pages-in-pdfs/

]]> Mon, 26 Jul 2021 22:11:10 +0000 http://www.quickpdf.org/forum/addimagefromstring_topic3942_post15844.html#15844 <![CDATA[AddImageFromString : instead you should try LastErrorCode...]]> http://www.quickpdf.org/forum/addimagefromstring_topic3942_post15843.html#15843 Author: Ingo
Subject: 3942
Posted: 26 Jul 21 at 10:06PM

instead you should try LastErrorCode directly after the function call.
Perhaps then you'll get a more detailed info about the error.

]]> Mon, 26 Jul 2021 22:06:39 +0000 http://www.quickpdf.org/forum/addimagefromstring_topic3942_post15843.html#15843 <![CDATA[AddImageFromString : For the DLL version the C++ header...]]> http://www.quickpdf.org/forum/addimagefromstring_topic3942_post15841.html#15841 Author: eborger
Subject: 3942
Posted: 25 Jul 21 at 5:52PM

For the DLL version the C++ header (QPDF 18) declares the parameter as a string, not a wstring. Your guess is as good as mine as to the format it expects, but I would try pointing it at a simple array of bytes containing the file contents. Of course this data may contain byte values of zero, so it is not really a null-terminated string.

this is what I did, and I get an 0 (error) return .... so I guess it must have some kind of header or something.... I will try contacting support...

Thanks

]]> Sun, 25 Jul 2021 17:52:30 +0000 http://www.quickpdf.org/forum/addimagefromstring_topic3942_post15841.html#15841 <![CDATA[AddImageFromString : I have never used this function...]]> http://www.quickpdf.org/forum/addimagefromstring_topic3942_post15840.html#15840 Author: tfrost
Subject: 3942
Posted: 25 Jul 21 at 10:58AM

I have never used this function (and never want to, after looking into it), so all I know is what is in the documentation and what the Delphi IDE tells me. For Delphi, the DCU object file (QPDF 18) says the parameter is a WideString, but in the (QPDF 16) source code that I no longer use it is declared as an AnsiString and moved directly into a memorystream for use. This is one reason why it is not worth my experimenting in Delphi, because would be is simpler to use ...fromStream and be certain, if I needed this functionality!

For the ActiveX version, the QPDF 18 documentation makes clear that it is a string of 16-bit characters, and that only the low 8 bits of each character are used. So this function needs work to create its parameter from real-world image data, before you can call it in this way.

]]> Sun, 25 Jul 2021 10:58:32 +0000 http://www.quickpdf.org/forum/addimagefromstring_topic3942_post15840.html#15840 <![CDATA[AddImageFromString : with AddImageFromFile it works...]]> http://www.quickpdf.org/forum/addimagefromstring_topic3942_post15839.html#15839 Author: eborger
Subject: 3942
Posted: 24 Jul 21 at 9:32PM

with AddImageFromFile it works fine, so the question is how should the string be built ?

I am using Xbase++ language which is C++ based, and calling the DLL version of the lib.

Is there a prefix to the string ? what is the valid format of the string ?

Thanks,

Edgar

]]> Sat, 24 Jul 2021 21:32:56 +0000 http://www.quickpdf.org/forum/addimagefromstring_topic3942_post15839.html#15839 <![CDATA[AddImageFromString : If you have the images as files,...]]> http://www.quickpdf.org/forum/addimagefromstring_topic3942_post15838.html#15838 Author: tfrost
Subject: 3942
Posted: 24 Jul 21 at 7:17PM

If you have the images as files, have you already tried AddImageFromFile? If this works, then you have ruled out any problem about the data. If there is some reason why you cannot use files in your application, then how you build the string depends on what programming language you are using, which you have not said.]]> Sat, 24 Jul 2021 19:17:15 +0000 http://www.quickpdf.org/forum/addimagefromstring_topic3942_post15838.html#15838 <![CDATA[AddImageFromString : Hello,I am trying to use the AddImageFromString...]]> http://www.quickpdf.org/forum/addimagefromstring_topic3942_post15837.html#15837 Author: eborger
Subject: 3942
Posted: 24 Jul 21 at 6:15PM

Hello,

I am trying to use the AddImageFromString function, but get a 0 result (error), what kind of string should this be ?

I loaded a BMP and a JPG file into memory, but it does not work, can you help me ?

thank you,

Edgar

]]> Sat, 24 Jul 2021 18:15:23 +0000 http://www.quickpdf.org/forum/addimagefromstring_topic3942_post15837.html#15837