Getting the file path by using a window handle.

Or  as a function:

Shane


function GetExePath(WH : HWND): String;
var
  dwActiveProcessId : DWORD;
  Snap   : THandle;
  pe32   : TPROCESSENTRY32;
Begin
 result:= '';
  GetWindowThreadProcessId(WH, @dwActiveProcessId );
  try
    Snap := CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS,
dwActiveProcessId);
    if Snap <> 0 then
    begin
      if Process32First(Snap, pe32) then
      begin
        if pe32.th32ProcessID = dwActiveProcessId then
        begin
          result := String(pe32.szExeFile);
        end
        else
        begin
          while Process32Next(Snap, pe32) do
          begin
            if pe32.th32ProcessID = dwActiveProcessId then
            begin
              Result := String(pe32.szExeFile);
              Break;
            end; //of: if pe32.th32ProcessID = dwActiveProcessId
          end; //of while
        end; //of else
      end; //of: if Process32First(Snap, pe32)
    end; //of: if Snap <> 0
  finally
    CloseHandle(Snap);
  end;
end;

The toolhelp functions can be used everywhere except NT4. The problem is that while the toolhelp functions do return the full file path in win9x, they only return the file NAME in the winNT family. So if you need the full path in the NT family you need to use PsApi.dll. This works in the whole winNT family, but not in win9x.

Soory, your right, i was typing so fast, i got my self reversed, however, the code does use the psAPI.dll

SMILE

SHane

Which code uses the pasApi.dll? Your code uses toolhelp32. Now I'm confused...   :-)

Yeah, im confusing my self as well.

It is quite complicated, in fact. as quoted from (Peter Below (TeamB))

"Win16:

  use GetWindowWord( hwnd, GWW_INSTANCE ) to get the module handle, with that
  GetModuleFilename gets the exe name. ExtractIcon can be used to fetch an
  icon from the EXE.
 
Win95/98, NT 5.0:
  use GetWindowThreadProcessID to get the process ID from the window handle.
  Use Toolhelp32 to enumerate all running processes and look for one with a
  matching process ID. The process info contains the exe name. Get icon with
  ExtractIconEx or ShGetFileInfo. Delphi comes with an import unit for
  Toolhelp32 (tlhelp32).

NT 4.0:
  use GetWindowThreadProcessID to get the process ID from the window handle.
  Use PSAPI.DLL to enumerate all running processes and look for one with a
  matching process ID. The process info contains the exe name. Get icon with
  ExtractIconEx or ShGetFileInfo. A import unit for PSAPI.DLL can be
  downloaded from www.xapware.com or http://www.wilsonc.demon.co.uk."


Shane

But as I said before, the toolhelp functions do NOT give us the full file path when being used in the NT family. And the question is about getting the full file path in the NT family. So that means toolhelp is no go.

You need to use PsApi.dll. That works in NT4, Windows 2000, Windows XP and Windows 2003 - but not in win9x.

So how would I use psAPI.dll to achieve this?

Win95/98, NT 5.0:
  use GetWindowThreadProcessID to get the process ID from the window handle.
  Use Toolhelp32 to enumerate all running processes and look for one with a
  matching process ID. The process info contains the exe name. Get icon with
  ExtractIconEx or ShGetFileInfo. Delphi comes with an import unit for
  Toolhelp32 (tlhelp32).

SHane

OK Madshi, im listening...... cause i think im confused., hopefully you can set me straight as well....

code please....

Shane

THANKS Madshi!

Shane

I was hoping to keep the program as small as possible, besides I will be using this program at work, so that solution looks like a no-go...hmm this is harder then it should be...

Just do a search on google. I'm sure that I've seen some Delphi psapi.dll sources somewhen somewhere. Look for "Delphi psapi".

Yup, and when I did, i found this great source of yours....

In win9x the code also gives you the full path, but
not in win2k and winXP. In those systems you need
to use psApi.dll to get the full path:

http://www.howtodothings.com/showarticle.asp?article=142

Shane

Hi,

just to (hopefully) complete the above comments:

function GetExenameForProcessUsingPSAPI(pid: DWord): String;
var
  i: Integer;
  cbNeeded: DWord;
  modules: array [1..1024] of hInst;
  ProcHandle: THandle;
  filename: array [0..512] of Char;
begin
  SetLastError(0);
  result := '';
  ProcHandle := OpenProcess(PROCESS_QUERY_INFORMATION or PROCESS_VM_READ, false, pid);
  if (ProcHandle <> 0) then
  try
    if (EnumProcessModules(ProcHandle, @modules[1], SizeOf(modules), cbNeeded)) then
      for i := 1 to cbNeeded div SizeOf(hInst) do
      begin
        if (GetModuleFilenameEx(ProcHandle, modules[i], filename, SizeOf(filename)) > 0) then
          if (AnsiStrIComp(PChar(ExtractFileExt(filename) + #0), '.exe' ) = 0) then
          begin
            Result := filename;
            break;
          end;
      end;
  finally
    CloseHandle(ProcHandle);
  end;
end;

function GetExenameForProcessUsingToolhelp32(pid: DWord): String;
var
  snapshot: THandle;
  procentry: TProcessEntry32;
  ret: bool;
begin
  SetLastError(0);
  Result := '';
  snapshot:= CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
  if (snapshot <> INVALID_HANDLE_VALUE) then
  try
    procentry.dwSize := Sizeof(procentry);
    ret := Process32FIRST(snapshot, procentry);
    while ret do
    begin
      if (procentry.th32ProcessID = pid) then
      begin
        Result := procentry.szExeFile;
        break;
      end else
        ret := Process32Next(snapshot, procentry);
    end;
  finally
    CloseHandle(snapshot);
  end;
End;

function GetExenameForProcess(pid: DWord): String;
begin
  if (Win32Platform = VER_PLATFORM_WIN32_NT) and (Win32MajorVersion <= 5)
  then
    Result := GetExenameForProcessUsingPSAPI(pid)
  else
    Result := GetExenameForProcessUsingToolhelp32(pid);
end;

function GetExenameForWindow(wnd: hWnd): String;
var
  pid: DWord;
begin
  Result := '';
  if isWindow(Wnd) then
  begin
    GetWindowThreadProcessID(Wnd, @pid);
    if (pid <> 0) then Result := GetExenameForProcess(pid);
  end;
end;

Regards,
Markus

The GetModuleFileName function retrieves the full path and filename for the executable file containing the specified module.

DWORD GetModuleFileName(
    HMODULE hModule,      // handle to module to find filename for
    LPTSTR lpFilename,      // pointer to buffer for module path
    DWORD nSize       // size of buffer, in characters
   );      
 

Parameters:
   hModule - Identifies the module whose executable filename is being requested. If this parameter is NULL, GetModuleFileName returns the path for the file used to create the calling process.
   lpFilename - Points to a buffer that is filled in with the path and filename of the given module.
   nSize - Specifies the length, in characters, of the lpFilename buffer. If the length of the path and filename exceeds this limit, the string is truncated.

Return Values
If the function succeeds, the return value is the length, in characters, of the string copied to the buffer.
If the function fails, the return value is zero. To get extended error information, call GetLastError.