I need help - I can help - AddImageFromString() in C++ DLL Project (RESOLVED)

AddImageFromString() in C++ DLL Project (RESOLVED)

Printed From: Debenu Quick PDF Library - PDF SDK Community Forum
Category: For Users of the Library
Forum Name: I need help - I can help
Forum Description: Problems and solutions while programming with the Debenu Quick PDF Library and Debenu PDF Viewer SDK
URL: http://www.quickpdf.org/forum/forum_posts.asp?TID=2144
Printed Date: 04 Jul 25 at 9:43AM
Software Version: Web Wiz Forums 11.01 - http://www.webwizforums.com

Topic: AddImageFromString() in C++ DLL Project (RESOLVED)

Posted By: barqyDev
Subject: AddImageFromString() in C++ DLL Project (RESOLVED)
Date Posted: 10 Feb 12 at 8:30PM

I'm using Visual Studio 2010 in a MFC Dialog App and I would like to be able to

place images in my PDF that come from bitmaps stored in my resource file

reason 1 - don't want to have files travelling with the app. I'd like it as standalone as possible

reason 2 - don't want to create temporary files on disk just to load with AddImageFromFile()

I've tried loading the image into memory with CImage:

CImage Image;

Image.LoadFromResource( AfxGetInstanceHandle(), MAKEINTRESOURCE(IDB_VESSIX) );

I have access to the bitmap data via Image.GetBits(), but it's not clear to me

what format data AddImageFromString() actually wants.

I know it takes a std::string parameter, but that doesn't say what it's expecting.

Any help would be appreciated!

Replies:

Posted By: barqyDev
Date Posted: 10 Feb 12 at 9:19PM

I do have a working project using AddImageFromFile() it just makes me unhappy for the reasons mentioned.

Posted By: barqyDev
Date Posted: 10 Feb 12 at 10:24PM

Another update....loaded a JPG from disk into a PDF file:

CImage image;

image.LoadFromResource( AfxGetInstanceHandle(), MAKEINTRESOURCE(IDR_LOGO) );

image.Save( L"test.jpg" );

index = pdf.AddImageFromFile( L"test.jpg", 0 );

pdf.SelectImage( index );

pdf.DrawImage( 0, 0, 100, 100 );

// all that above works

// now, let's what data got stuffed into the PDF

index = pdf.GetPageImageList(0);

std::string Grab = pdf.GetImageListItemDataToString( index, 1, 0 );

// and it looks like the exact same content as what's in my JPG file on disk.

Assuming I have that right, I'm now chunking through some more API calls:

FindResource

LoadResource

LockResource

SizeofResource

Hopefully I'm on the right track.

Posted By: AndrewC
Date Posted: 11 Feb 12 at 2:13AM

AddImage from file expects a full BMP, JPG, PNG or TIFF file. It sounds like you are on the right track extracting the JPEG resource.

Here is a post that gives some hope. The last reply indicates that it might work better when the JPG is marked as RCDATA in the resource file.

http://www.sfml-dev.org/forum/viewtopic.php?p=33890&sid=ba955874d6e717c8b858ede78a74c029 - http://www.sfml-dev.org/forum/viewtopic.php?p=33890&sid=ba955874d6e717c8b858ede78a74c029

Posted By: barqyDev
Date Posted: 11 Feb 12 at 8:03AM

Thank you for your reply today, it helped!

Unfortunately, I remained my own worst enemy. After the the RCDATA update, I was getting the data and length right, but it wasn't working.

After dinner I came back and took a look at the actual call to AddImageFromString() that I was making. Turns out I wasn't getting all the data stuffed into the std::string I thought I was. I only got the first chunk of bytes up to the first NULL.

Builidng my input parameter with this helped: std::string test( res_data, res_size );

So....Here's the working code block for anybody else that might stroll by:

int result = 0;

HINSTANCE Instance = AfxGetInstanceHandle();

HRSRC res = FindResource( Instance,MAKEINTRESOURCE( IDB_BINARY ), RT_RCDATA );

if( res )

{

HGLOBAL res_handle = LoadResource( Instance , res );

if( res_handle )

{

char *res_data = (char *) LockResource( res_handle );

if( res_data )

{

DWORD res_size = SizeofResource( Instance, res );

if( res_size )

{

std::string test( res_data, res_size );

result = m_PdfWriter->AddImageFromString( test, 0 );

m_PdfWriter->SelectImage( result );

m_PdfWriter->DrawImage( 550, 5, 60, 60 );

} // got the length

} // locked it..i.e. got pointer to 1st byte

} // loaded the resource

} // found the resource item