How to find out if process created with ShellExecuteEx owns a window? - c++

Question

I'm using ShellExecuteEx to run external application:
SHELLEXECUTEINFO shExInfo = { 0 };
shExInfo.cbSize = sizeof(shExInfo);
shExInfo.fMask = SEE_MASK_NOCLOSEPROCESS;
shExInfo.hwnd = 0;
shExInfo.lpVerb = L"runas"; // Operation to perform
shExInfo.lpFile = windowStringContainingAppPath.c_str(); // Application to start
shExInfo.lpParameters = windowStringContainingAppParameters.c_str(); // Additional parameters
shExInfo.lpDirectory = 0;
shExInfo.nShow = SW_SHOW;
shExInfo.hInstApp = 0;
if(ShellExecuteEx(&shExInfo))
{
WaitForSingleObject(shExInfo.hProcess, INFINITE);
DeleteFile(wsMesh3dx64Parameter.c_str());
CloseHandle(shExInfo.hProcess);
}
Everything works perfectly but there exist an unplanned behaviour of this external app that after closing its main window its process is still active.
This prevents WaitForSingleObject(shExInfo.hProcess, INFINITE); from returning and I have to terminate the process manualy.
Instead I'm looking for a way to replace WaitForSingleObject(shExInfo.hProcess, INFINITE);with a loop that checks if external process owns a window and if not terminate it.
This is what I thought of but if there is a better way please point it out for me.
UPDATE:
Thanks to Robson answer I managed to do what I intended to:
struct Porcess_ID_HWND
{
DWORD processID;
HWND processhWnd;
};
BOOL CALLBACK EnumWindowsProc(HWND hWnd, LPARAM lParam)
{
Porcess_ID_HWND*info = (Porcess_ID_HWND*)lParam;
DWORD processID;
GetWindowThreadProcessId(hWnd, &processID);
if (processID == info->processID){
info->processhWnd = hWnd;
return FALSE;
}
return TRUE;
}
And my loop:
if(ShellExecuteEx(&shExInfo))
{
DWORD dwProcessID = GetProcessId(shExInfo.hProcess);
Porcess_ID_HWND info;
info.processID = dwProcessID;
// wait for window to appear
do
{
info.processhWnd = NULL;
EnumWindows(EnumWindowsProc, (LPARAM)&info);
} while (!info.processhWnd);
// wait for window to close
do
{
info.processhWnd = NULL;
EnumWindows(EnumWindowsProc, (LPARAM)&info);
} while (info.processhWnd);
//WaitForSingleObject(shExInfo.hProcess, INFINITE);
DeleteFile(wsMesh3dx64Parameter.c_str());
CloseHandle(shExInfo.hProcess);
}

Answer 1

found a good answer at http://forums.codeguru.com/showthread.php?392273-RESOLVED-How-to-get-window-s-HWND-from-it-s-process-handle
1)
HAVE: Process ID, NEED: Process handle
Solution: OpenProcess()
2)
HAVE: Process handle, NEED: Process ID
Solution: GetProcessId()
3)
HAVE: Window handle, NEED: Process ID
Solution: GetWindowThreadProcessId()
4)
HAVE: Window handle, NEED: Process handle
Solution: Use 3) and then 1)
5)
HAVE: Process ID, NEED: Window handle
Solution: EnumWindows(), then in the callback function do 3) and check if it matches your process ID.
6)
HAVE: Process handle, NEED: Window handle
Solution: 2) and then 5)
so you are in case 6. then if no window handle's process ID is matched with your shExInfo.hProcess's process ID then shExInfo.hProcess owns no window