|
|
[CLoadLibrary : Loads Libraries (DLL's) ] | ||
Environment: Win 95/98 VC6 SP4 Loading libraries in windows is very simple : all you need is call ::LoadLibrary(path to library)
and you get the handle to the library . But what to do with it ?
The primary use to this class if for extracting some functions ,
Meanwhile I added functionality for extracting by Name (which is relatively inefficient method to use when extarcting
functions from DLLs) . (In the future I'll add functions by their index ,(order number))
This class is supposed to be put on stack. it includes 3 types of constructors :
you may use the default constructor or else supply a dll file name (+the extension)
you dont need to supply the full path if this DLL is under the Windows directory or
System directory . The function will find internally the full path.
LoadLibrary returns HINSTANCE : a handle to the library. Internally : windows
maintains a reference count to the loaded libraries (as if the were COM objects)
loads them only if not alredy loaded and "releases" (unloads) only if reference count drops
to 0.
CLoadLibrary();
CLoadLibrary(LPCTSTR lpszFileName);
CLoadLibrary(LPCTSTR lpszFileName,BOOL bSystemDirectory,BOOL bWindowsDirectory);
Loading of library is done in the function : Load(...) as you see it gets the relative/full path
and 2 booleans (to indicate system/windows directory) . It return TRUE for
success , FALSE for failure. Currently the function (class allows loading only DLLs : it
does an extra check (checks for .dll extension in file path). The check is done
within the Load function.
BOOL Load(LPCTSTR lpszFileName,BOOL bSystemDirectory=FALSE,BOOL bWindowsDirectory=FALSE);
There are 2 information functions : you may get the instance handle (be warned dont mess with it)
or the full path name of library.
HINSTANCE GetInstance() { return hInstance; }
CString GetLibrary() { return m_strLibrary; }
Currently this class serves as a base class to other classes I wrote :
already available CLibraryFuncExtractor classes, or
gives services to other classes : A very common use for such class is determining
library version (using DLLVERSIONINFO). I didn't add such functionality : this is rather simple
(yet tricky) and mainly because there are free implementations of this feature in the internet.
Protected functions : Free() : frees the library : and done automaticly on destruction
and FindProc(...) : to extract a function from this DLL is used internaly by this class
or its' derived classes.
