C / C++ / MFC

21-Dec-05 9:45

Hi All,
I am a novice and would appreciate any help you guys can give me here. I want to write a code which will tell me with which window the user is currently interacting. The code I am using is

#include <windows.h>

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
LPSTR lpCmdLine, int nCmdShow)
{
int test;
HWND hwnd;
MSG Msg;
TCHAR szBuf[80];
int nMaxCount;
DWORD d;
int nCmdShow;

while(1)
{
hwnd=GetActiveWindow();

if(hwnd == NULL)
{
MessageBox(NULL, "No window is currently active!","Error!" MB_ICONEXCLAMATION | MB_OK);
return 0;
}

ShowWindow(hwnd, nCmdShow);
UpdateWindow(hwnd);

test=GetWindowText(hwnd,szBuf,80);

}

}

Here GetActiveWindow returns NULL .If I use GetForegroundWindow, I get the handle of the IDE i.e VC++ and so on. How do I write a code which will tell me which is the window the user is currently interacting with?. My ultimate aim is to figure out which is the currently active window and grab images from the window. So in this case would I need to run an exe from my main code which will give me the handle to the active window? Any better idea how do I do it? Waiting for replies from the experts out there!!
-confused newbie

TheGreatAndPowerfulOz21-Dec-05 9:52

21-Dec-05 9:52

GetActiveWindow returns windows relative the the current thread, not the entire system.

From the docs:

The GetActiveWindow function retrieves the window handle to the active window attached to the calling thread's message queue.

Syntax

HWND GetActiveWindow(VOID);
Return Value

The return value is the handle to the active window attached to the calling thread's message queue. Otherwise, the return value is NULL.

GetForegroundWindow is the one you want to use. The docs say:

The GetForegroundWindow function returns a handle to the foreground window (the window with which the user is currently working). The system assigns a slightly higher priority to the thread that creates the foreground window than it does to other threads.

wilbur_logan21-Dec-05 10:02

21-Dec-05 10:02

Hey Ahz,
Thanks for clearing tht up!!!!. Now assuming I use GetForegroundWindow, I get the handle to the foreground window. In my case I get the handle to the VC IDE becuase thats the window I am currently interacting.I want to have a standalone application that will run in the background and give me the handle to the foreground window.. how do i do that?. Or can I launch this exe from another program. The issue is something like this...anytime a user is interacting with a window, I need to get a handle to that window and then selectively capture some graphics from that window. How do i proceed in this case? THanks!!!

TheGreatAndPowerfulOz21-Dec-05 10:18

21-Dec-05 10:18

just run your program from the Run key or place it in all-users startup directory.

Look into using SetWindowsHookEx

wilbur_logan21-Dec-05 10:40

21-Dec-05 10:40

Hey Ahz, I will try using SetWindowsHookEx and see. Thanks. Can you give me a high level idea how my program should look like..I mean how do I implement it. For ex should I have a seperate application for letting me know which is the active window and should my main prog run this exe, get the handle from it (is this possible?) use the handle to grab some image from the window and then do some processing on the image...Yeah m a confused newbie so pls bear with my inane questions! THanks again!

Rajesh R Subramanian21-Dec-05 17:22

Rajesh R Subramanian

21-Dec-05 17:22

wilbur_logan wrote:
I want to have a standalone application that will run in the background and give me the handle to the foreground window.. how do i do that?.

Clearly, you need to write a system wide hook. Depending on your need, it may be a keyboard hook, a mouse hook, or etc etc.

Regards,
Rajesh R. Subramanian.

You have an apple and me too. We exchange those and We have an apple each.
You have an idea and me too. We exchange those and We have two ideas each.

-- modified at 23:23 Wednesday 21st December, 2005

wilbur_logan22-Dec-05 7:39

Erase item from std::vector?

22-Dec-05 7:39

Thanks for all the suggestions guys!

Lord Kixdemp21-Dec-05 9:38

21-Dec-05 9:38

Hello everyone! Big Grin | :-D

Is there an easy way to use std::vector::erase() without having to code my own class? In other words, how can I remove an item at a specified index? Thanks! Wink | ;-)

Lord Kixdemp
www.SulfurMidis.com
www.SulfurSoft.tk
[ftp://][http://][hotline://]tsfc.ath.cx

TheGreatAndPowerfulOz21-Dec-05 9:39

21-Dec-05 9:39

std::vector<MyClass> foo;
int someIndex = 10;
foo.erase(foo.begin() + someIndex);

-- modified at 15:40 Wednesday 21st December, 2005

Lord Kixdemp21-Dec-05 9:51

21-Dec-05 9:51

Whoops... I had tried that before, but it turned out that the index I was using was invalid... Thanks! Big Grin | :-D

Lord Kixdemp
www.SulfurMidis.com
www.SulfurSoft.tk
[ftp://][http://][hotline://]tsfc.ath.cx

toxcct21-Dec-05 21:38

toxcct

21-Dec-05 21:38

yes, test the vector length before calling erase() and/or test if begin() is different of end()...

TOXCCT >>> GEII power
[toxcct][VisualCalc 2.20][VisualCalc 3.0]

Lord Kixdemp24-Dec-05 16:11

24-Dec-05 16:11

Thanks!

Lord Kixdemp
www.SulfurMidis.com
www.SulfurSoft.tk
[ftp://][http://][hotline://]tsfc.ath.cx

Event

sam117321-Dec-05 8:49

sam1173

21-Dec-05 8:49

Helo!

What should i do to notify an envent to de Frame when y click left mouse on a view

thanks!

Re: Event

TheGreatAndPowerfulOz21-Dec-05 9:38

Swapping items in ListBox?

21-Dec-05 9:38

handle WM_LBUTTONDOWN

if using MFC: add an OnLButtonDown handler

Re: Event

sam117321-Dec-05 10:54

sam1173

21-Dec-05 10:54

thanks!

but wat i need is to resize the windowframe when i click on the client area

Re: Event

Blake Miller22-Dec-05 6:07

Blake Miller

22-Dec-05 6:07

Look into the CFrameWnd::RecalcLayout function.

No shirt, no shoes, no brains, no service.

Lord Kixdemp21-Dec-05 8:17

21-Dec-05 8:17

Hello everyone! Big Grin | :-D

OK, I've been trying many things, with InsertString(), DeleteString(), and SetItemData(), but nothing works! I looked on Google but nothing... Can anyone tell me? Thanks! Wink | ;-)

Lord Kixdemp
www.SulfurMidis.com
www.SulfurSoft.tk
[ftp://][http://][hotline://]tsfc.ath.cx

David Crow21-Dec-05 8:27

David Crow

21-Dec-05 8:27

For MFC, use CListBox::InsertString(). Otherwise, send the control a LB_INSERTSTRING message.

"Take only what you need and leave the land as you found it." - Native American Proverb

Lord Kixdemp21-Dec-05 9:06

21-Dec-05 9:06

InsertString() just adds an item at the index you specify, it doesn't replace the current value of that item... Unsure | :~

Know another way? Thanks! Wink | ;-)

Lord Kixdemp
www.SulfurMidis.com
www.SulfurSoft.tk
[ftp://][http://][hotline://]tsfc.ath.cx

PJ Arends21-Dec-05 9:23

PJ Arends

21-Dec-05 9:23

DeleteString() and InsertString()

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Lord Kixdemp21-Dec-05 9:26

21-Dec-05 9:26

But in which order? That was the first thing I tried... Frown | :-(

Thanks!

Lord Kixdemp
www.SulfurMidis.com
www.SulfurSoft.tk
[ftp://][http://][hotline://]tsfc.ath.cx

PJ Arends21-Dec-05 9:40

PJ Arends

21-Dec-05 9:40

Strings are numbered from zero to count_of_strings minus one, so to replace a string at a certain index, first delete the existing string, then insert the replacement

int SwapString(CListBox &Box, int Index, LPCTSTR NewString)
{
   ASSERT (Index < Box.GetCount());
 
   Box.DeleteString(Index);
   return Box.InsertString(Index, NewString);
}

If you insert the replacement string first, you then have to increase the index value before you delete the old string or else you will just end up deleting the string you just inserted.

Maximilien21-Dec-05 10:04

Maximilien

21-Dec-05 10:04

be careful that your listbox is not set to "auto sort";

also, when deleting/inserting an item, the indexes will shift.

Maximilien Lincourt
Your Head A Splode - Strong Bad