sample_213.md

Home

Loading a string resource from an executable file

Code:

DO declare

LOCAL lcSysDir, hModule, lFreeModule, lcBuffer, lnBufsize, ii, loPChar
lcSysDir = GetSysDir()
lFreeModule = .F.
hModule = GetHandle(lcSysDir + "\wininet.dll", @lFreeModule)

* try also:
* lcSysDir + "\mshtml.dll"
* lcSysDir + "\vbrun500.dll"
* lcSysDir + "\mapi32.dll"
* lcSysDir + "\comdlg32.dll"
* lcSysDir + "\syssetup.dll"
* lcSysDir + "\userenv.dll"

IF hModule <> 0
	CREATE CURSOR cs (id N(6), txt C(250))
	loPChar = CreateObject("PChar", Repli(Chr(0), 256))

	FOR ii=0 TO 4096
		lnBufsize = LoadString(hModule, ii, loPChar.GetAddr(), 1024)
		IF lnBufsize <> 0
			INSERT INTO cs VALUES (ii, SUBSTR(loPChar.GetValue(), 1, lnBufsize))
		ENDIF
	ENDFOR

	IF lFreeModule
		= FreeLibrary(hModule)
	ENDIF
	
	GO TOP
	BROWSE NORMAL NOWAIT
ENDIF

FUNCTION GetHandle(lcModuleName, lRelease)
	LOCAL hModule
	hModule = GetModuleHandle(lcModuleName)
	IF hModule <> 0
		lRelease = .F.
	ELSE
		lRelease = .T.
		hModule = LoadLibrary(lcModuleName)
	ENDIF
RETURN hModule

FUNCTION GetSysDir
	DECLARE INTEGER GetSystemDirectory IN kernel32;
		STRING @lpBuffer, INTEGER nSize

	LOCAL lcBuffer, lnResult
	lcBuffer = SPACE(250)
	lnResult = GetSystemDirectory(@lcBuffer, Len(lcBuffer))
RETURN Left(lcBuffer, lnResult)

IF nSizeRet <> 0
	lpBuffer = SUBSTR(lpBuffer, 1, nSizeRet)
	? lpBuffer
ENDIF

PROCEDURE declare
	DECLARE INTEGER LoadString IN user32;
		INTEGER hInstance, INTEGER uID,;
		INTEGER lpBuffer, INTEGER nBufferMax

	DECLARE INTEGER LoadLibrary IN kernel32 STRING lpLibFileName
	DECLARE INTEGER FreeLibrary IN kernel32 INTEGER hLibModule
	DECLARE INTEGER GetModuleHandle IN kernel32 STRING lpModuleName

DEFINE CLASS PChar As Custom
	PROTECTED hMem

PROCEDURE Init(lcString)
	THIS.hMem = 0
	THIS.SetValue(lcString)

PROCEDURE Destroy
	THIS.ReleaseString

FUNCTION getAddr  && returns a pointer to the string
RETURN THIS.hMem

FUNCTION GetValue && returns string value
	LOCAL lnSize, lcBuffer
	lnSize = THIS.GetAllocSize()
	lcBuffer = SPACE(lnSize)

	IF THIS.hMem <> 0
		DECLARE RtlMoveMemory IN kernel32 As Heap2Str;
			STRING @, INTEGER, INTEGER
		= Heap2Str(@lcBuffer, THIS.hMem, lnSize)
	ENDIF
RETURN lcBuffer

FUNCTION GetAllocSize  && returns allocated memory size (string length)
	DECLARE INTEGER GlobalSize IN kernel32 INTEGER hMem
RETURN Iif(THIS.hMem=0, 0, GlobalSize(THIS.hMem))

PROCEDURE SetValue(lcString) && assigns new string value
#DEFINE GMEM_FIXED   0
	THIS.ReleaseString

	DECLARE INTEGER GlobalAlloc IN kernel32 INTEGER, INTEGER
	DECLARE RtlMoveMemory IN kernel32 As Str2Heap;
		INTEGER, STRING @, INTEGER

	LOCAL lnSize
	lcString = lcString + Chr(0)
	lnSize = Len(lcString)
	THIS.hMem = GlobalAlloc(GMEM_FIXED, lnSize)
	IF THIS.hMem <> 0
		= Str2Heap(THIS.hMem, @lcString, lnSize)
	ENDIF

PROCEDURE ReleaseString  && releases allocated memory
	IF THIS.hMem <> 0
		DECLARE INTEGER GlobalFree IN kernel32 INTEGER
		= GlobalFree(THIS.hMem)
		THIS.hMem = 0
	ENDIF
ENDDEFINE  

---

Listed functions:

FreeLibrary
GetModuleHandle
GetSystemDirectory
GlobalAlloc
GlobalFree
GlobalSize
LoadLibrary
LoadString