DLL won't load

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   We update client programs remotely by storing the *.exe in a database blob record on a central server. When updates are available, they are loaded from the server to the client and written to the local PC.

With Windows 7, that means that we can't use \program files\* since it would take elevated permissions, etc.

So, we install and update the programs for the client in \user\app data\roaming\subdir\*

That works fine... except... the DLL version (also placed in the roaming directory), will not load in our report programs.

We use a declare to create the library:
soft declare function QuickPDFCreateLibrary lib pdflib () as integer

The programming platform is RealSoftware, so the syntax of the declare may be a bit different that VB6, etc. The pdflib is a string constant with the name of the dll "QuickPDFDLL0722.dll"

I can get it to load if I place the DLL in "\Program Files\subdir\QuickPDFDLL0722.dll" and reference the pdflib constant to that address, but it just won't load if it is in the roaming directory.

The programs on the client all run from the roaming directory.

Help!

RAG
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RAG Members Profile Find Members Posts Beginner Joined: 05 Jan 11 Location: Oregon. USA Status: Offline Points: 1	Post Options Post Reply Quote RAG Report Post Thanks(0) Quote Reply Topic: DLL won't load Posted: 05 Jan 11 at 11:48PM
	We update client programs remotely by storing the .exe in a database blob record on a central server. When updates are available, they are loaded from the server to the client and written to the local PC. With Windows 7, that means that we can't use \program files\ since it would take elevated permissions, etc. So, we install and update the programs for the client in \user\app data\roaming\subdir\* That works fine... except... the DLL version (also placed in the roaming directory), will not load in our report programs. We use a declare to create the library: soft declare function QuickPDFCreateLibrary lib pdflib () as integer The programming platform is RealSoftware, so the syntax of the declare may be a bit different that VB6, etc. The pdflib is a string constant with the name of the dll "QuickPDFDLL0722.dll" I can get it to load if I place the DLL in "\Program Files\subdir\QuickPDFDLL0722.dll" and reference the pdflib constant to that address, but it just won't load if it is in the roaming directory. The programs on the client all run from the roaming directory. Help! RAG ------------

AndrewC Members Profile Find Members Posts Moderator Group Joined: 08 Dec 10 Location: Geelong, Aust Status: Offline Points: 841	Post Options Post Reply Quote AndrewC Report Post Thanks(0) Quote Reply Posted: 09 Jan 11 at 1:35AM
	What is the exact error message when the program runs on the client PC and it cannot find / load the DLL. I also assume you are trying this in a debugger. What is the return value of the LoadLibrary call. Maybe that will give you more information. An EXE file should also search for DLL's in the current directory. ie . The same directory as the EXE file itself. This sounds like what you want to happen but it is not working. Have your tried posting a support call to RealSoftware. It you can get the DLL to load in a different location then it is unlikely to be related to QuickPDF but more to RealSoftware. Do you use other DLL's in the same way with RealSoftware. If not you many want to quickly load a different DLL to see if it has the same problem.

Ingo Members Profile Find Members Posts Moderator Group Joined: 29 Oct 05 Status: Offline Points: 3529	Post Options Post Reply Quote Ingo Report Post Thanks(0) Quote Reply Posted: 09 Jan 11 at 3:41PM
	Hi RAG! Normally applications using dlls are looking first in system32 or sysWow64 and after this they are looking in the own app-directory. If there are different dlls on the system (in system32 and app-path for example) this can be a problem? Cheers and welcome here, Ingo

Dimitry Members Profile Find Members Posts Team Player Joined: 18 Feb 10 Status: Offline Points: 37	Post Options Post Reply Quote Dimitry Report Post Thanks(0) Quote Reply Posted: 12 Jan 11 at 2:33AM
	System path variable %USERPROFILE% value should be used for proper access to ..\Application Data (..\AppData\Roaming). The %USERPROFILE% path is usually used to store application data including executable files and libraries which actually can be executed/loaded. The problem may appear with %USERPROFILE% folders access rights. Here is Delphi code snippet that may help you. It was tested with Windows XP and Windows 7. If it doesn't work you should check user and folders access rights matching. uses QuickPDFDLL0723; const USER_PROFILE = 'USERPROFILE'; APPLICATION_DATA = '\Application Data'; WORK_DIR = '\subdir'; LIBRARY_NAME = '\QuickPDFDLL0723.dll'; var libpath: string; qpl: TQuickPDFDLL0723; begin libpath := GetEnvironmentVariable(USER_PROFILE) + APPLICATION_DATA + WORK_DIR + LIBRARY_NAME; // Check is QuickPDF*.dll exists at libpath if not FileExists(libpath) then Exit; qpl := TQuickPDFDLL0723.Create(libpath); try with qpl do begin UnlockKey('type your license key here'); SetOrigin(1); DrawText(100, 100, 'Hello DLL!'); SaveToFile('sample.pdf'); end; finally qpl.Free; end; end;
	Regards, Dmitry