Need keyboard and mouse events for already created window?

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Hi everybody!
I need to read events from an existing window, so I cannot just create a new one.

To read Kbd events, I need to use GetRawInput, but before I can use it I need to receive WM_INPUT from the WndProc callback. Since the window has already been created I cannot assign the callback function like I could from the call to CreateWindow. So how do I get the WM_INPUT message?

Thanks!

Posted 13-Feb-11 3:43am

micard

Updated 13-Feb-11 4:16am

Manfred Rudolf Bihy

v3

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Manfred Rudolf Bihy 13-Feb-11 10:10am

Edit for clarity. Adjusted title for clarity as well.

3 solutions

Solution 3

In case hooking is too much (it gets all the messages from the system, not only from the window you need) The more proper technique (since the time of the first Petzold!) is subclassing:

just write something like:

C++

WNDPROC oldproc;
LRESULT CALLBACK yourproc(HWND h, UINT u, WPARAM w, LPARAM l)
{
   /* DO YOUR MESSAGE PROCESSING AND TEHN ... */

   return CallWindowProc(oldproc,h,u,w,l);
}

and setup the subclassing as

oldproc = (WNDPROC)SetWindowLongPtr(yourHwnd, GWL_WNDPROC, (LONG_PTR)yourproc);

and from there, yopuproc will start receiving th messages of your window.

Posted 13-Feb-11 9:56am

Emilio Garavaglia

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Andrew Brock 15-Feb-11 10:45am

This is what I would do. 5+.

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Nish Nishant · Accepted Answer · 2011-02-13T04:09:00

Solution 1

You need to install a hook. Google for "global keyboard mouse hook" and you'll get what you want.

For some sample code on creating a CBT hook, take a look at this article I wrote (several years ago, but the core concepts remain the same today):

Manipulating Windows using messages and simple CBT hooking[^]

Posted 13-Feb-11 4:09am

Nish Nishant

Updated 13-Feb-11 4:12am

v3

Comments

Manfred Rudolf Bihy 13-Feb-11 10:15am

Nice link! 5+
I see that the article employs the same function I advertized. :)

Nish Nishant 13-Feb-11 10:16am

Thank you.

Sergey Alexandrovich Kryukov 13-Feb-11 11:56am

All right, 5.
--SA

Harrison H 13-Feb-11 16:06pm

Good link, to your article no less! My 5

micard 15-Feb-11 10:40am

i created 2 files, one for the exe and one for the dll

My code looks like this:
//EXE file
typedef void (*SetHook)(HMODULE);

int main()
{
SetHook SetHookFunc;
HMODULE hModule = LoadLibrary("Hook.dll");

SetHookFunc = (SetHook)GetProcAddress(hModule, "SetHook");
SetHookFunc(hModule);
while(true)
{
Sleep(100);
}
return 0;
}

//Hook.dll file
static HHOOK hKBHook;

extern "C"
{
_declspec (dllexport) LRESULT CALLBACK KeyboardProc(int nCode, WPARAM wParam, LPARAM lParam);
{
//some processing
}

_declspec (dllexport) void SetHook(HMODULE hMod)
{
HMODULE hDLL = hMod;

hKBHook = SetWindowshookEx(WH_KEYBOARD, KeyboardProc, hDLL, 0);
printf("SetHook\n");
}
_declspec (dllexport) void UnsetHook(void);
{
//some processing
}
_declspec (dllexport) BOOL APIENTRY DLLMain()
{
//some processing
}
}

I compile then debug by breakpoint using VS2008, but after successful return from SetHook, callback function is not called, I tried typing on a notepad application, or the actual VS2008 or the cmd prompt used for debugging, but nothing happens.

Can anyone help me.
thanks!

Stephen Hewitt 15-Feb-11 11:06am

To me a hook seems like overkill. I'd go with the subclassing approach as mentioned above if I could.

Nish Nishant 15-Feb-11 11:11am

Agree, as long as the window is in the same process. The OP has not clarified that yet.

micard 21-Feb-11 0:44am

i need to hook to another process, not the created application..

for example, hook to a notepad? how do I do that?

I used FindWindow() ad GetWindowThreadProcessId() but when I use the returned value of GetWindowThreadProcessId() to SetWindowsHookEx, it fails.

Manfred Rudolf Bihy · Accepted Answer · 2011-02-13T04:13:00

Solution 2

This function will do the nescessary manipulations for you: SetWindowsHookEx[^]

Hope that helps!

Cheers!

Posted 13-Feb-11 4:13am

Manfred Rudolf Bihy

Comments

Manfred Rudolf Bihy 13-Feb-11 10:16am

I just realized Nishant posted a link to a great article. Please also look there!
Thanks!

Nish Nishant 13-Feb-11 10:16am

Voted 5, the API you gave him is all the OP really needs.

Manfred Rudolf Bihy 13-Feb-11 10:18am

Thanks! I appreciate it.

Sergey Alexandrovich Kryukov 13-Feb-11 11:57am

Quite enough, my 5.
--SA

Manfred Rudolf Bihy 13-Feb-11 12:06pm

Thanks SA!
I hope you don't mind refering to you as SA as always seem to break my fingers when type SAkryukov. :)

Sergey Alexandrovich Kryukov 13-Feb-11 14:34pm

This is the most appropriate way to call me; it is derived from "Sergey Alexandrovich", which is the appropriate polite addressing in my culture, but also served as my nick (my close friends also used it for many years, so it became a nick rather than normal polite addressing) in both full and abbreviated form. Using last name (even last name with the title) is considered to be too formal to be acceptable, mostly used by police or in the army.
Thank you very much.
--SA

Manfred Rudolf Bihy 13-Feb-11 14:41pm

I was considering Sergey because I visited the homepage you linked to in your profile, but I thought it beter to make sure. :)
Maybe I'll change mine to MRB because we're already doing enough typing as it is.

Sergey Alexandrovich Kryukov 13-Feb-11 14:43pm

This is absolutely fine, too. Whatever you prefer.
Thank you for being so kind.
--SA

Manfred Rudolf Bihy 13-Feb-11 14:52pm

For some cultures I'm not quite sure what the family name and what the given name is.

Sergey Alexandrovich Kryukov 13-Feb-11 15:33pm

As I mentioned, it is not always the case, you're absolutely right.

Historically, given names are always present. Sometimes, there are given, but not in arbitrary manner: they can be strictly defined by the day (as in case as Saints names) and other factor; there is a practice of giving "secret" names (I have close friends who were named using the remnants of this ancient magical culture), and so on. As to family names, they appear everywhere with change in society structure, gradually (starting from upper classes) and quite late (in many cases, the tradition did not become common before 19 or 20 century, in other places, it is not common even now: one CodeProject Article author from southern India reported the he created his "family" name himself when he was relocating to USA; this name is almost as long as the present comment :-).
The world is multi-cultural; ignoring it, mostly by people from Western Europe and Northern America creates all kind of problems.
--SA

Sergey Alexandrovich Kryukov 13-Feb-11 15:35pm

I actually referred to my Answer we've discussed recently, about fullname.Split.
--SA

Sergey Alexandrovich Kryukov 13-Feb-11 14:46pm

I an hurry I would read MRB as Master Boot Record, ignoring different order. If you decide to do so, I'll need to be extra careful. At the same time, the way we call you if unique enough for this community, and I'll never mind extra typing to call you by your name :-)
--SA

Manfred Rudolf Bihy 13-Feb-11 14:48pm

Then just stay with "Manfred". :)
We'll think of something else if another one turns up.

Sergey Alexandrovich Kryukov 13-Feb-11 15:22pm

:-)

micard 15-Feb-11 10:40am

i created 2 files, one for the exe and one for the dll

My code looks like this:
//EXE file
typedef void (*SetHook)(HMODULE);

int main()
{
SetHook SetHookFunc;
HMODULE hModule = LoadLibrary("Hook.dll");

SetHookFunc = (SetHook)GetProcAddress(hModule, "SetHook");
SetHookFunc(hModule);
while(true)
{
Sleep(100);
}
return 0;
}

//Hook.dll file
static HHOOK hKBHook;

extern "C"
{
_declspec (dllexport) LRESULT CALLBACK KeyboardProc(int nCode, WPARAM wParam, LPARAM lParam);
{
//some processing
}

_declspec (dllexport) void SetHook(HMODULE hMod)
{
HMODULE hDLL = hMod;

hKBHook = SetWindowshookEx(WH_KEYBOARD, KeyboardProc, hDLL, 0);
printf("SetHook\n");
}
_declspec (dllexport) void UnsetHook(void);
{
//some processing
}
_declspec (dllexport) BOOL APIENTRY DLLMain()
{
//some processing
}
}

I compile then debug by breakpoint using VS2008, but after successful return from SetHook, callback function is not called, I tried typing on a notepad application, or the actual VS2008 or the cmd prompt used for debugging, but nothing happens.

Can anyone help me.
thanks!