We help IT Professionals succeed at work.

Getting the main window of a thread (VC++)

SeanPS
SeanPS asked
on
408 Views
Last Modified: 2013-12-03
I've launched a process using CreateProcess (so I have the associated PROCESS_INFORMATION and STARTUPINFO stuff).  How do I get the process's main window?

thanks  
Comment
Watch Question

Commented:
Unlock this solution and get a sample of our free trial.
(No credit card required)
UNLOCK SOLUTION

Commented:
A minor correction.  GetWindowThreadProcessId() returns the thread ID and sets the second argument to the process ID.  The PROCESS_INFORMATION structure will contain both.

Something like (modulo bugs and missing parts):

    HWND global_hwnd = NULL;

    int WINAPI WinMain(...)
    {
        PROCESS_INFORMATION pi;
        CreateProcess(..., &pi);
        WaitForInputIdle(pi.hProcess, INFINITE);
        EnumWindows(EnumWindowsProc, (LPARAM)pi.dwProcessId);

        if (global_hwnd != NULL)
        {
            // Do whatever...
        }

        // ...
    }

    BOOL CALLBACK EnumWindowsProc(HWND hwnd, LPARAM lParam)
    {
        DWORD pid;
        GetWindowThreadProcessId(hwnd, &pid);
        if (pid == (DWORD)lParam)
        {
            global_hwnd = hwnd; // Found the window
            return FALSE;
        }
        else return TRUE;
    }

Author

Commented:
Adjusted points to 100

Commented:
Have fun!

Author

Commented:
based on your original ideas, it seems that EnumThreadWindows() is a slightly better alternative.  i was hoping that i could easily create a CWinThread object from the stuff i have, but that doesn't seem to be the case.

thanks for your help
sean

Commented:
>> it seems that EnumThreadWindows() is a slightly better alternative.
It is, provided that only one thread in the process is creating windows.

>> i was hoping that i could easily create a CWinThread object from the stuff i have
Check the MFC sources.  You'll see that CWinThread is a complicated beast.
Unlock the solution to this question.
Thanks for using Experts Exchange.

Please provide your email to receive a sample view!

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

OR

Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.