用三级跳隐藏进程的问题

Question

需要注入的key.dll的代码如下：
function HookProc(ncode,wparam,lparam:Integer):Integer;stdcall;
begin
  MessageBox(0,'sfsfasfsafsaf','fsf',0);
  Result:=CallNextHookEx(oldhook,ncode,wparam,lparam);
end;
procedure SetHook;export;
begin
  oldhook:=SetWindowsHookEx(WH_KEYBOARD,@HookProc,HInstance,0);
  MessageBox(0,PChar(inttostr(oldhook)),'sd',0);
end;
exports
  SetHook;
===========================================================================
运行后发现，key.dll确认已被注入到指定进程，key.dll的SetHook过程确实执行了，因为有一个对话框跳出并显示了一串数字，但是按键后却没有任何对话框跳出来，也就是说key.dll的HookProc函数并没有被调用，请问这是为什么？

Answer 1

中间DLL的代码如下：
procedure Load;
var
  LibHd:THandle;
begin
  Jumped:=True;
  LibHd:=LoadLibrary(PChar('D:\Program Files\Borland\Delphi7\Projects\hook\Jump\key.dll'));
  RealDLL:=GetProcAddress(LibHd,'SetHook');
  if @RealDLL<>nil then
  RealDLL
  else
  begin
    MessageBox(0,'f','dd',0);
    FreeLibrary(LibHd);
  end;
end;function JumpProc(ncode:Integer;wparam:WPARAM;lparam:LPARAM):LRESULT;stdcall;
var
  pid:Cardinal;
begin
  if Jumped=False then
  begin
    ThreadHd:=CreateThread(nil,0,@Load,nil,0,pid);
    Jumped:=True;
  end;
  Result:=CallNextHookEx(JumpHook,ncode,wparam,lparam);
end;procedure SetHook(ExpID:DWORD);stdcall;export;
begin
  JumpHook:=SetWindowsHookEx(WH_GETMESSAGE,@JumpProc,HInstance,ExpID);
  Jumped:=False;
end;