Simulating keypress with SendMessage

The handle is correct since I can read the title of the window and display the same in a messagebox

Amit

i think you used something like GetForegroundWindow or EnumWindows to get the handle.

the bad news is, that if i'm right, you got some hide-and-seek to pley.

try to use EnumWindowEx to find all sub windows of your current window handle.
iteratively send your message to the first, second, third and so on window, maybe in a loop
with a delay in it, so you can see when it works.

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winui/WinUI/WindowsUserInterface/Windowing/Windows/WindowReference/WindowFunctions/EnumChildWindows.asp
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winui/WinUI/WindowsUserInterface/Windowing/Windows.asp

ops, sorry, you were too quick

hm, however, a window can have sub windows,
and if you send your keystrokes to the parent,
it can happen that they're no processed.
give it a try

No, I get the window handle using a global hook
and window does not contain any child controls.......at least it doesn't seem to have

Amit

hm, strange.

could it be that

SendMessage ( handle, WM_KEYUP, 67, -1070727167) ;      

needs to be

SendMessage ( handle, WM_SYSKEYUP, 67, -1070727167) ;      

?

last thing that comes to my mind (or try changing alls WM_SYSKEY*o WM_KEY* ?)

Nope, that is the sequence of messages u get when u actually press ALT+C

Amit

I tried sending the Messages for simulating a Mouse click but of no use

Amit

I have another aspect:

SendMessage ( handle, WM_KEYUP, 67, -1070727167) ;

what is handle?  or, more exact: where does handle point to?
maybe you sent your messages to the wrong window or to the nirvana...
you can try this:

handle = GetForegroundWindow();

or this

handle = GetDesktopWindow();      // I don't know it the function exist with THIS name ?!?

regards
void_main

void_main,

handle points to the destination window
I have confirmed its correct by getting the titke of that window using handle

Also, i am not sure about using GetForeGroundWindow()........Is it necessary that the window should be in ForeGround so that we could send message to that window
I don't think so

Amit

Tried with Enum.... method also.....but to no use

amit

Maybe we can think another way... Is ALT+C an accelerator to a menu item? If so, you can use a WM_COMMAND message

I have only used CWnd::PostMessage, but with success.

Have you tried to get a CWnd pointer via CWnd::FromHandle and using that pointer? Either PostMessage or SendMessage.

SteH is right, even my SPy++ says it's PostMessage :)

Another idea: Will the other app recognize the key stroke ony using WM_KEYUP or should you mimic the entire sequence it would get when you press ALT+C:
WM_(SYS)KEYDOWN for ALT, WM_KEYDOWN for C, WM_KEYUP for C, WM_(SYS)KEYUP for ALT. I would think handling should act on xx_KEYDOWN not on keyup.
Or are the calls you gave in the first post that sequence?

I am sure you've all looked into a help file. This is from borland c++ builder 6.0:
You don't have to read everything (I copied everything to deliver as much information as possible)
Please look at "remarks"

-----------------------
The SendMessage function sends the specified message to a window or windows. The function calls the window procedure for the specified window and does not return until the window procedure has processed the message. The PostMessage function, in contrast, posts a message to a thread's message queue and returns immediately.

LRESULT SendMessage(

    HWND hWnd,      // handle of destination window
    UINT Msg,      // message to send
    WPARAM wParam,      // first message parameter
    LPARAM lParam       // second message parameter
   );      
 

Parameters

hWnd

Identifies the window whose window procedure will receive the message. If this parameter is HWND_BROADCAST, the message is sent to all top-level windows in the system, including disabled or invisible unowned windows, overlapped windows, and pop-up windows; but the message is not sent to child windows.

Msg

Specifies the message to be sent.

wParam

Specifies additional message-specific information.

lParam

Specifies additional message-specific information.

 

Return Values

The return value specifies the result of the message processing and depends on the message sent.

Remarks

Applications that need to communicate using HWND_BROADCAST should use the RegisterWindowMessage function to obtain a unique message for inter-application communication.
If the specified window was created by the calling thread, the window procedure is called immediately as a subroutine. If the specified window was created by a different thread, Windows switches to that thread and calls the appropriate window procedure. Messages sent between threads are processed only when the receiving thread executes message retrieval code. The sending thread is blocked until the receiving thread processes the message.
-----------------------

maybe it helps a bit
void_main

void_main,

I had read this in msdn.....but it does not help much because as I said, I am able to send messages to a window (created using basic windows SDK programming) and print those messgaes there
But i am not able to simulate the keyboard keypress OR mouse click

 
SteH,

I tried with PostMessage as well......no use
Also, I am not using MFC, hence cannot use CWND::SendMessgae.........I am using the global SendMessage


Amit

Fellas! you miss one thing. If you get window caption by window handle it is wrong window to copy/paste it is overlapped/MDI/Dialog window but is not window where you want to get text. handle must be retrieved only GetFocus function. GetFocus gives handle of window where real text is placed. Moreover Did you select text to copy?

MikProg,

THat window is not having k/b focus
Hence GetFocus() wont work (i guess)

Amit

void_main,

The link u posted doesn't seem to open on my PC
However, my net connection seems to be quite slow today.
I shall check that link (if it opens) once my net connection gets good

Amit

And if you are playing with hooks you could try to use the journaling hook to simulate the keystrokes. Just a thought.

If your sure you have the correct handle try using SetActiveWindow or SetFocus then send your keyboard message.

EnumWindows is unreliable unless you know your target is going to have a specific title and/or classname.

I tried to use EnumWindows for controlling ShellExecute untill I discovered WaitForSingleObject thing.. I even use FlashWindow in a loop just to flash a window to prove I had the correct handle.


RJ

Okay: Here's the text from the link:

Simulate Keypress

If you've ever wanted to programatically fire a keboard event then I have just the VI for you. This code makes a call to the Windows API calling a function in user32.dll available in all Windows versions. This function allows you to specify any key on the keyboard. When the VI is run, Windows will think the selected key has been pressed.

Looking at the function description available from MSDN we see the following:

keybd_event Function
--------------------------------------------------------------------------------
The keybd_event function synthesizes a keystroke. The system can use such a synthesized keystroke to generate a WM_KEYUP or WM_KEYDOWN message. The keyboard driver's interrupt handler calls the keybd_event function.
Syntax

VOID keybd_event(BYTE bVk,
BYTE bScan,
DWORD dwFlags,
PTR dwExtraInfo
);

Parameters
bVk
[in] Specifies a virtual-key code. The code must be a value in the range 1 to 254. For a complete list, see Virtual-Key Codes.

bScan
This parameter is not used.

dwFlags
[in] Specifies various aspects of function operation. This parameter can be one or more of the following values.

KEYEVENTF_EXTENDEDKEY
If specified, the scan code was preceded by a prefix byte having the value 0xE0 (224).

KEYEVENTF_KEYUP
If specified, the key is being released. If not specified, the key is being depressed.

dwExtraInfo
[in] Specifies an additional value associated with the key stroke.

Return Value
This function has no return value.


There are two inputs we need to be concerned about. The bScan and dwFlags. For the bScan we need to input the number which represents the key on your keyboard. This number is also available from MSDN. I won't display the complete list since you can retrieve it online from MSDN but I have included the complete list on the diagram of the VI.To make it easier during programming, I've created an enum control for all the possible keyboard values (0-254).

Another input of concern as mentioned above is the dwFlags. This must be toggled between 0 and 2 to indicate that a key is either depressed or released. This is especialy usefull with the ctrl or shift keys. I've created the following diagram and front panel for the above function.


(source:   http://www.aivaliotis.com/archives/lv/simulate_keypress.shtml)


void_main

Stop here! When searching answer I loose myself in question. Lets go step by step.

>I wish to simulate pressing ALT+C to a particcular window.................If I create a dummy window (using basic SDK.....
I see you do it well.

>Actually the window has a hyperlink which has a shortcut as ALT+C
Hyperlink is a IHlink COM object that can not have shortcut. Thus shortcut ALT+C is shortcut to anything else that can have shortcuts. How do you realize that?

>>Hyperlink is a IHlink COM object that can not have shortcut. Thus shortcut ALT+C is shortcut to anything else that can have shortcuts. How do you realize that?

MikProg,

Just try NetMeeting using MSN Messenger      
Login in to two MSN messenger accounts on two PC's
From one PC, Start a NetMeeting session and select the other users name and click OK
A request would be send to the other user [A window is shown to other user which has Accept/Decline as Hyperlinks which also have k/b shortcuts like ALT+C for Accepting and .......(i dont remember) for Declining

Amit

I'm shure in this case ALT-C combo processed elsewhere but not window function. Hot keys are created in windows in several ways. But mostly common is accelerators tables. Native windows application hides accelerators tables deep inside. The main idea of AT is catch keyboard input message, substitute by WM_COMMAND with predefined parameters and send WM_COMMAND to destination. This process takes place inside message loop so the only way is to send messages that emulates keyborad input to thread that owns destination window.

var
  threadid, dw: DWORD;
begin
  threadid:=GetWindowThreadProcessId(Handle,dw);
  PostThreadMessage(threadid,WM_SYSKEYDOWN, 18, 540540929) ;  
... more messages to send to emulate ALT-C
end;
 

i think void_main's solution with the keybd_event api is the correct one ... one thing though, that keyb_event sends the keystroke to the window that has the focus, so, before calling keybd_event, u need to call SetForegroundWindow passing the window handle, and then use keybd_event.

I tried with keybd_event
                  SetForegroundWindow ( handle ) ;
                  keybd_event ( VK_MENU, 0, 0, 0 ) ;
                  keybd_event ( 'C', 0, 0, 0 ) ;
                  keybd_event ( 'C', 0, KEYEVENTF_KEYUP, 0 ) ;
                  keybd_event ( VK_MENU, 0, KEYEVENTF_KEYUP, 0 ) ;

but to no success

Any ideas

Amit

I think keybd_event is depricated now. Try using SendInput instead.

Try

keybd_event(VK_MENU, MapVirtualKey(VK_MENU, 0), 0, 0);
keybd_event('C', MapVirtualKey('C', 0), 0, 0);
keybd_event('C', MapVirtualKey('C', 0), KEYEVENTF_KEYUP, 0);
keybd_event(VK_MENU, MapVirtualKey(VK_MENU, 0), KEYEVENTF_KEYUP, 0)

i don't know if the above is correct or not, but i used the following to send and enter key to a window (its kinda simple, coz i didn't have to dela with the menu ... etc --- isn't there a direct shortcut to wht u are trying to do instead of first clcking on the menu ??)

---------
SetForegroundWindow(handle);
keybd_event(VK_RETURN,0,0,0);
---------------

Though my actual problem didn't get solved, I did receive some good comments/suggestions

So, an accept is also fine for me

Let me know whether I should accept (i.e. split)

Amit

Sys_Prog ,

You should decide. I would say - make a split :)

Venabili