Как вызывать функцию 16-битной DLL из 32-битного приложения
Надо использовать Thunks.
Кусок работающего только под Windows 95 кода -
const
Gfsr_SystemResources = 0;
Gfsr_GdiResources = 1;
Gfsr_UserResources = 2;
var
hInst16: THandle;
GFSR: Pointer;
{ Undocumented Kernel32 calls. }
function LoadLibrary16(LibraryName: PChar): THandle; stdcall; external kernel32 index 35;
<>FreeLibrary16(HInstance: THandle); stdcall; external kernel32 index 36;
function GetProcAddress16(Hinstance: THandle; ProcName: PChar): Pointer; stdcall; external kernel32 index 37;
procedure QT_Thunk; cdecl; external kernel32 name 'QT_Thunk';
{ QT_Thunk needs a stack frame. }
{$StackFrames On}
{ Thunking call to 16-bit USER.EXE. The ThunkTrash argument
allocates space on the stack for QT_Thunk. }
function NewGetFreeSystemResources(SysResource: Word): Word;
var
ThunkTrash: array[0..$20] of Word;
begin
{ Prevent the optimizer from getting rid of ThunkTrash. }
ThunkTrash[0] := hInst16;
hInst16 := LoadLibrary16('user.exe');
if hInst16 < 32 then
raise Exception.Create('Can''t load USER.EXE!');
{ Decrement the usage count. This doesn't really free the
library, since USER.EXE is always loaded. }
FreeLibrary16(hInst16);
{ Get the function pointer for the 16-bit function in USER.EXE. }
GFSR := GetProcAddress16(hInst16, 'GetFreeSystemResources');
if GFSR = nil then
raise Exception.Create('Can''t get address of GetFreeSystemResources!');
{ Thunk down to USER.EXE. }
asm
push SysResource { push arguments }
mov edx, GFSR { load 16-bit procedure pointer }
call QT_Thunk { call thunk }
mov Result, ax { save the result }
end;
end;