Article 4500 Subject Re: Hook Api (Textout, ExTextOut, DrawText) to get text from any window: How ?

Hook Api (Textout, ExTextOut, DrawText) to get text from any window: How ?

just tried injecting dll into target process
procedure TMainHookTestForm.Button3Click(Sender: TObject);var   Process: dword;   StartInfo: TStartupInfo;   ProcInfo: TProcessInformation;   pid:Cardinal;Begin

pid:=GetTargetProcessId; // by using CreateToolhelp32Snapshot,Process32Next, etc.. dont know easy way

     Process := OpenProcess(PROCESS_ALL_ACCESS,False,pid);
     InjectLibrary(Process, 'D:\TextHook.dll'); // downloaded utils afxCodeHook

end;



and it seems textout hook is working fineits getting all text from target application and listview (which is the purpose)however its getting all textout text which is cumbersome to process

need help to figure out how do i exactly get text from specified point from specified window (HDC)

i mean how do i implement it in dll

ThanksKamlesh

> {quote:title=Kamlesh Chauhan wrote:}{quote}> Dear Friends> > (with ref. to prev ques.)> i m trying to get text from this window and it seems> only option i have now is> hooking textout, drawtext, etc.. api> > both following (Non OCR) is able to capture-extract-grab, text from this window> http://www.hook-api.com/> http://www.renovation-software.com/en/text-grab-sdk/textgrab-sdk.html> > looking for some link, sample code, etc.. to get started from> > > > Thanks> Kamlesh> > Edit: > --------------> i downloaded one hook code-util and > was trying following code and it seems to work fine> only problem is it captures text only from my application form> > > ??> > > ====================================================> library TextHook;> > uses>     SysUtils,>     Windows,>     Messages,>     Math,>     DHDisasm,>     DHDisasmEx,>     DHHook,>     DHKernel,>     DHProcess,>     DHProtect,>     DHUtil;> > Type>     PHookInfo = ^KHookInfo;>     KHookInfo = Packed Record>               Hook:HHook;>               Text1:array[0..255] of Char;>               Text2:array[0..255] of Char;>               x,y:Integer;>     End;> > Var>   FMapping: THandle = 0;>   FHookInfo: PHookInfo = nil;>   vFile:TextFile;> >   oldTextOutA, nextTextOutA: function(DC: HDC; X, Y: Integer; Str: PAnsiChar; Count: Integer): BOOL; stdcall;>   oldTextOutW, nextTextOutW: function(DC: HDC; X, Y: Integer; Str: PWideChar; Count: Integer): BOOL; stdcall;> >   oldExtTextOutA, nextExtTextOutA: function(DC: HDC; X, Y: Integer; Options: Longint; Rect: PRect; Str: PAnsiChar; Count: Longint; Dx: PInteger): BOOL; stdcall;>   oldExtTextOutW, nextExtTextOutW: function(DC: HDC; X, Y: Integer; Options: Longint; Rect: PRect; Str: PWideChar; Count: Longint; Dx: PInteger): BOOL; stdcall;> > procedure textW(w:PWideChar; c: integer);> Var>    vStr:String;> begin>      Try>         vStr := WideCharToString(w);>         Append(vFile);>         WriteLn(vFile,vStr);>      Except>            MessageBeep(MB_ICONASTERISK);>      End;> end;> > procedure textA(s:PAnsiChar; c: integer);> Var>    vStr:String;> begin>      Try>         vStr:=StrPAs(S);>         Append(vFile);>         Write(vFile,vStr);>      Except>            MessageBeep(MB_ICONASTERISK);>      End;> end;> > function myTextOutA(DC: HDC; X, Y: Integer; Str: PAnsiChar; Count: Integer): BOOL; stdcall;> begin>     textA(Str,count);>     result := nextTextOutA(DC,X,Y,Str,Count);> end;> > function myTextOutW(DC: HDC; X, Y: Integer; Str: PWideChar; Count: Integer): BOOL; stdcall;> begin>      textW(Str,count);>      result := nextTextOutW(DC,X,Y,Str,Count);> end;> > function myExtTextOutA(DC: HDC; X, Y: Integer; Options: Longint; Rect: PRect; Str: PAnsiChar; Count: Longint; Dx: PInteger): BOOL; stdcall;> begin>     textA(Str,count);>     result := nextExtTextOutA(DC,X,Y,Options,rect,Str,Count,dx);> end;> > function myExtTextOutW(DC: HDC; X, Y: Integer; Options: Longint; Rect: PRect; Str: PWideChar; Count: Longint; Dx: PInteger): BOOL; stdcall;> begin>     textW(Str,count);>     result := nextExtTextOutW(DC,X,Y,Options,rect,Str,Count,dx);> end;> > Procedure InjectMain;> Var>    h: integer;> Begin>   h :=  GetModuleHandle('gdi32.dll');>   if h > 0 then>   begin>     @oldTextOutA := GetProcAddress(h,'TextOutA');>     if @oldTextOutA <> nil then>       DHHook.HookCode(@oldTextOutA,@myTextOutA,@nextTextOutA);> >     @oldTextOutW := GetProcAddress(h,'TextOutW');>     if @oldTextOutW <> nil then>       DHHook.HookCode(@oldTextOutW,@myTextOutW,@nextTextOutW);> >     @oldExtTextOutA := GetProcAddress(h,'ExtTextOutA');>     if @oldExtTextOutA <> nil then>       DHHook.HookCode(@oldExtTextOutA,@myExtTextOutA,@nextExtTextOutA);> >     @oldExtTextOutW := GetProcAddress(h,'ExtTextOutW');>     if @oldExtTextOutW <> nil then>       DHHook.HookCode(@oldExtTextOutW,@myExtTextOutW,@nextExtTextOutW);>   end;> end;> > procedure uninjectmain;> begin>   DHHook.UnhookCode(@nextTextOutA);>   DHHook.UnhookCode(@nextTextOutW);>   DHHook.UnhookCode(@nextExtTextOutA);>   DHHook.UnhookCode(@nextExtTextOutW);> end;> > Procedure DllMain(Reason: Integer);> Begin>      Case Reason of>           DLL_PROCESS_ATTACH:>           Begin>                FMapping := CreateFileMapping(INVALID_HANDLE_VALUE, nil, PAGE_READWRITE, 0, SizeOf(KHookInfo), 'KC_HookInfo');>                If FMapping = 0 then Exit;>                FHookInfo := PHookInfo( MapViewOfFile( FMapping, FILE_MAP_WRITE, 0, 0, SizeOf(KHookInfo) ) );>                If FHookInfo = Nil Then Exit;>                Assignfile(vFile,'D:\a2.txt');>                If FileExists('D:\a2.txt') Then Reset(vFile) Else Rewrite(vFile);>                InjectMain;>           End;>           DLL_PROCESS_DETACH:>           Begin>                UnInjectMain;>                closefile(vFile);>                If FHookInfo <> Nil then UnmapViewOfFile(FHookInfo);>                If FMapping <> 0 then CloseHandle(FMapping);>           End;>      End;> End;> > Begin>      DllProc := @DllMain;>      DllMain(DLL_PROCESS_ATTACH);> end.> ===========================================================> > Edited by: Kamlesh Chauhan on Dec 15, 2010 1:03 AM