Get path of a known HWND

Question

I'm trying to make an app that will run something only if in the moment that the dll is called, the window that is focused in that moment has the same path as a values that is given. That being said, the following code will be added in a dll which will have a function with the path value as it parameter that returns true if the condition is met, or false otherwise. The problem I have is that I can't seem to find a way to get the path of the focused window, the following code always returns an empty string. And I can't simply use the title of the windows because there are apps that yes, the title is static like Task Manager, but there are others that the title is changed, like Windows Explorer changes it's title depending where the user is in. What do I have to change?

The following code is used only as a test, because later on that is the base for what I need, and I will only have to add a comparison on path variable, and based on that to return true or false:

#include "Windows.h";
#include <iostream>
#include <chrono>
#include <thread>
using namespace std;

int main() {
    // 2 seconds delay to have time to switch windows
    std::this_thread::sleep_for(std::chrono::milliseconds(2000));

    HWND hWnd = GetForegroundWindow(); 
    int length = GetWindowTextLength(hWnd);
    wchar_t* title = new wchar_t[length];
    GetWindowTextW(hWnd, title, length);

    DWORD id;
    GetWindowThreadProcessId(hWnd, &id); 

    wchar_t* path = new wchar_t[MAX_PATH];
    HANDLE hProc = OpenProcess(PROCESS_ALL_ACCESS, FALSE, id);
    GetModuleFileNameW((HMODULE)hProc, path, MAX_PATH);
    CloseHandle(hProc);

    wcout << "ID: " << id << " | Title: " << title << " | Path: " << path << endl << endl;
    return 1;
} 

Output example: ID: 2536 | Title: Task Manage | Path:

Answer 1

To get the result I wanted, I switched to QueryFullProcessImageName (like CherryDT suggested to take a look at), but you have to be careful, you need to run it with Admin rights to get the path for some apps like I encountered with Task Manager, maybe because it is an Windows app, not sure and you'll have to do some research on that if you need more details. Here is a little example:

#include "Windows.h";
#include <iostream>
#include <chrono>
#include <thread>
using namespace std;

int main() {
    // 2 seconds delay to have time to switch windows
    std::this_thread::sleep_for(std::chrono::milliseconds(2000));

    HWND hWnd = GetForegroundWindow(); 
    int lgth = GetWindowTextLength(hWnd) + 1;
    wchar_t* title = new wchar_t[lgth];
    GetWindowTextW(hWnd, title, lgth);

    DWORD id;
    GetWindowThreadProcessId(hWnd, &id); 

    wchar_t* path = new wchar_t[MAX_PATH];
    DWORD size = MAX_PATH;
    HANDLE hProc = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, id);
    QueryFullProcessImageNameW(hProc, 0, path, &size);
    CloseHandle(hProc);

    wcout << "ID: " << id << " | Title: " << title << " | Path: " << path << endl << endl;
    return 1;
} 

Output example: ID: 12580 | Title: Task Manage | Path: C:\Windows\System32\Taskmgr.exe

Answer 2

This is written in Dart, but might be helpful for people that wonder on this page. The problem with QueryFullProcessImageName is that for Microsoft Store apps it returns wrong path, usually FrameHost.exe

// ignore_for_file: non_constant_identifier_names

import 'dart:async';
import 'dart:ffi';
import 'package:ffi/ffi.dart';

import 'package:win32/win32.dart';

class AppxNamePath {
  bool? hasManifest;
  String? name;
  String? path;
}

class HwndPath {
  bool hasManifest = true;
  HwndPath();
  AppxNamePath GetAppxInstallLocation(hWnd) {
    //Ger Process Handle
    final ppID = calloc<Uint32>();
    GetWindowThreadProcessId(hWnd, ppID);
    var process = OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION, FALSE, ppID.value);
    free(ppID);

    //Get Text
    final cMax = calloc<Uint32>()..value = 512;
    var cAppName = wsalloc(cMax.value);
    GetApplicationUserModelId(process, cMax, cAppName);
    var name = cAppName.toDartString();
    free(cMax);

    //It's main Window Handle On EdgeView Apps, query first child
    if (name.isEmpty) {
      final parentHwnd = GetAncestor(hWnd, 2);
      final childWins = enumChildWins(parentHwnd);
      if (childWins.length > 1) {
        CloseHandle(process);
        hWnd = childWins[1];

        final ppID = calloc<Uint32>();
        GetWindowThreadProcessId(hWnd, ppID);
        process = OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION, FALSE, ppID.value);
        free(ppID);

        final cMax = calloc<Uint32>()..value = 512;
        GetApplicationUserModelId(process, cMax, cAppName);
        name = cAppName.toDartString();
        free(cMax);
      }
    }
    if (name.isEmpty) {
      return AppxNamePath()
        ..hasManifest = false
        ..name = "NoManifest"
        ..path = "C:\\";
    }

    //Get Package Name
    final familyLength = calloc<Uint32>()..value = 65 * 2;
    final familyName = wsalloc(familyLength.value);
    final packageLength = calloc<Uint32>()..value = 65 * 2;
    final packageName = wsalloc(familyLength.value);
    ParseApplicationUserModelId(cAppName, familyLength, familyName, packageLength, packageName);

    //Get Count
    final count = calloc<Uint32>();
    final buffer = calloc<Uint32>();
    FindPackagesByPackageFamily(familyName, 0x00000010 | 0x00000000, count, nullptr, buffer, nullptr, nullptr);
    final packageFullnames = calloc<Pointer<Utf16>>();
    final bufferString = wsalloc(buffer.value * 2);

    //Get Path
    FindPackagesByPackageFamily(familyName, 0x00000010 | 0x00000000, count, packageFullnames, buffer, bufferString, nullptr);
    final packageLocation = bufferString.toDartString();

    CloseHandle(process);
    free(cAppName);
    free(familyLength);
    free(familyName);
    free(packageLength);
    free(packageName);
    free(count);
    free(buffer);
    free(packageFullnames);
    free(bufferString);
    return AppxNamePath()
      ..name = name
      ..path = "C:\\Program Files\\WindowsApps\\$packageLocation"
      ..hasManifest = true;
  }

  String getProcessExePath(processID) {
    String exePath = "";
    final hProcess = OpenProcess(PROCESS_QUERY_INFORMATION | PROCESS_VM_READ, FALSE, processID);
    if (hProcess == 0) {
      CloseHandle(hProcess);
      return "";
    }
    final imgName = wsalloc(MAX_PATH);
    final buff = calloc<Uint32>()..value = MAX_PATH;
    if (QueryFullProcessImageName(hProcess, 0, imgName, buff) != 0) {
      final szModName = wsalloc(MAX_PATH);
      GetModuleFileNameEx(hProcess, 0, szModName, MAX_PATH);
      exePath = szModName.toDartString();
      free(szModName);
    } else {
      exePath = "";
    }
    free(imgName);
    free(buff);
    CloseHandle(hProcess);
    return exePath;
  }

  String getWindowExePath(hWnd) {
    String result = "";
    final pId = calloc<Uint32>();
    GetWindowThreadProcessId(hWnd, pId);
    final processID = pId.value;
    free(pId);

    result = getProcessExePath(processID);
    if (result.contains("FrameHost.exe")) {
      final wins = enumChildWins(hWnd);
      final winsProc = <int>[];
      int mainWinProcs = 0;
      for (var e in wins) {
        final xpId = calloc<Uint32>();

        GetWindowThreadProcessId(e, xpId);
        winsProc.add(xpId.value);
        if (processID != xpId.value) {
          mainWinProcs = xpId.value;
        }
        free(xpId);
      }
      if (mainWinProcs > 0) {
        result = getProcessExePath(mainWinProcs);
      }
    }
    return result;
  }

  String getFullPath(hWnd) {
    var exePath = getWindowExePath(hWnd);
    if (exePath.contains('WWAHost')) {
      final appx = GetAppxInstallLocation(hWnd);
      if (appx.hasManifest == true) {
        exePath = "${appx.path}";
      } else {
        exePath = "";
      }
    }
    return exePath;
  }
}

var __helperWinsList = <int>[];
int helperEnumWindowFunc(int w, int p) {
  __helperWinsList.add(w);
  return 1;
}

final wndProc = Pointer.fromFunction<EnumWindowsProc>(helperEnumWindowFunc, 0);

List enumChildWins(hWnd) {
  __helperWinsList.clear();
  EnumChildWindows(hWnd, wndProc, 0);
  return __helperWinsList;
}

//DLL IMPORTS

final _kernel32 = DynamicLibrary.open('kernel32.dll');

int QueryFullProcessImageName(int hProcess, int dwFlags, Pointer<Utf16> lpExeName, Pointer<Uint32> lpdwSize) => _QueryFullProcessImageName(hProcess, dwFlags, lpExeName, lpdwSize);

final _QueryFullProcessImageName = _kernel32.lookupFunction<Int32 Function(IntPtr hProcess, Uint32 dwFlags, Pointer<Utf16> lpExeName, Pointer<Uint32> lpdwSize),
    int Function(int hProcess, int dwFlags, Pointer<Utf16> lpExeName, Pointer<Uint32> lpdwSize)>('QueryFullProcessImageNameW');

int GetApplicationUserModelId(int hProcess, Pointer<Uint32> applicationUserModelIdLength, Pointer<Utf16> applicationUserModelId) =>
    _GetApplicationUserModelId(hProcess, applicationUserModelIdLength, applicationUserModelId);

final _GetApplicationUserModelId = _kernel32.lookupFunction<Uint32 Function(IntPtr hProcess, Pointer<Uint32> applicationUserModelIdLength, Pointer<Utf16> applicationUserModelId),
    int Function(int hProcess, Pointer<Uint32> applicationUserModelIdLength, Pointer<Utf16> applicationUserModelId)>('GetApplicationUserModelId');
int ParseApplicationUserModelId(Pointer<Utf16> applicationUserModelId, Pointer<Uint32> packageFamilyNameLength, Pointer<Utf16> packageFamilyName,
        Pointer<Uint32> packageRelativeApplicationIdLength, Pointer<Utf16> packageRelativeApplicationId) =>
    _ParseApplicationUserModelId(applicationUserModelId, packageFamilyNameLength, packageFamilyName, packageRelativeApplicationIdLength, packageRelativeApplicationId);

final _ParseApplicationUserModelId = _kernel32.lookupFunction<
    Uint32 Function(Pointer<Utf16> applicationUserModelId, Pointer<Uint32> packageFamilyNameLength, Pointer<Utf16> packageFamilyName,
        Pointer<Uint32> packageRelativeApplicationIdLength, Pointer<Utf16> packageRelativeApplicationId),
    int Function(Pointer<Utf16> applicationUserModelId, Pointer<Uint32> packageFamilyNameLength, Pointer<Utf16> packageFamilyName,
        Pointer<Uint32> packageRelativeApplicationIdLength, Pointer<Utf16> packageRelativeApplicationId)>('ParseApplicationUserModelId');

int lastHoveredHwnd = 0;
void main() {
  Timer.periodic(const Duration(milliseconds: 200), (timer) {
    final pos = calloc<POINT>();
    GetCursorPos(pos);
    final currentWin = WindowFromPoint(pos.ref);
    free(pos);
    final hWnd = GetAncestor(currentWin, 2);
    if (hWnd != lastHoveredHwnd) {
      lastHoveredHwnd = hWnd;
      final path = HwndPath().getFullPath(hWnd);
      print(path);
    }
  });
}