Thread: Hung up on GetWindowText

I've got it setup to just grab the process list without worrying about window captions. I think this will suit my purpose, at least for now.

Thanks

Originally Posted by Viper187

Can't I do this somehow with EnumProcesses? I can't find any decent examples of EnumWindows/EnumWindowsProc that just list them all. Do you simply check if the HWND != NULL in order to determine when to return TRUE/FALSE or what?

Give this a try...

Code:

#include <windows.h>
#include <stdio.h>

BOOL CALLBACK GetWindowFromProcessID(HWND hWnd, LPARAM lParam)
{
    static HWND hWnd2Find;
    static DWORD dwMatchProcessID;

    if(lParam != 0){
        dwMatchProcessID = (DWORD)hWnd;
        if(EnumWindows(GetWindowFromProcessID, 0))
            return FALSE;
        *(HWND *)lParam = hWnd2Find;
    }
    else{
        DWORD dwPID = 0;
        GetWindowThreadProcessId(hWnd, &dwPID);
        if(dwMatchProcessID == dwPID)
        {
            hWnd2Find = hWnd;
            return FALSE;
        }
    }
    return TRUE;
}

int main(void)
{
    HWND hWnd;
    DWORD dwPID = 3268;
    char szWindowTitle[500] = {0};

    if(GetWindowFromProcessID((HWND)dwPID, (DWORD)&hWnd))
    {
        GetWindowText(hWnd, szWindowTitle, sizeof(szWindowTitle)-1);
        printf("Window title is %s\n", szWindowTitle );   
    }
    else printf("No Window found\n");
    return 0;
}

Wow, That's pretty slick. However, it seems to be grabbing a random window instead of the parent/root window of the process. Any ideas for isolating it with this method? Is it just a matter of using/looping GetParent() or something?

However, it seems to be grabbing a random window instead of the parent/root window of the process. Any ideas for isolating it with this method? Is it just a matter of using/looping GetParent() or something?

The original code sample assumes that the first window found is the window of interest. This works fine with apps such as notepad. But it isn't appropriate for MDI apps such as MS Word etc. So, a modified solution would be to enumerate all windows for a particular process ID as follows:

Code:

#include <stdio.h>
#include <stdlib.h>
#include <windows.h>

void ListChildWindows(HWND hWnd, DWORD dwPIDCheck)
{
    DWORD dwPID;    
    char szBuffer[1000] = {0};
    GetWindowThreadProcessId(hWnd, &dwPID);
    GetWindowText(hWnd, szBuffer, 1000);
    if(dwPID == dwPIDCheck)
        printf("%-8X %-40s %-8d\n", hWnd, szBuffer,dwPID);
    for(hWnd = GetWindow(hWnd, GW_CHILD); hWnd != NULL; hWnd = GetWindow(hWnd, GW_HWNDNEXT))
        ListChildWindows(hWnd, dwPIDCheck);
}

int main(int argc, char **argv)
{
    HWND hDesktopWindow = NULL;
    if(argc == 1)
    {
        printf("Invalid  arguments\n");
        return 0;
    }
    hDesktopWindow = GetDesktopWindow();
    ListChildWindows(hDesktopWindow, atoi(argv[1]));
    return 0;
}