how to communicate or send messages from dialog1 to dialog2(sub dialog of dialog1) in MFC
1) #define MYMSG WM_USER + 3
2) define and implement disp. function in your dialog LRESULT OnMyMsg(WPARAM w, LPARAM l);
3) Add code to your message map ON_MESSAGE(MYMSG,OnMyMsg)
4) Send message myDlgPtr->SendMessage(MYMSG,0,0);
http://msdn.microsoft.com/en-us/library/ms644950(v=vs.85).aspx
Related
I am programming a really simple MFC C++ Application which is working with HotKeys. To set a HotKey I use the following method from the WinAPI for my application:
BOOL RegisterHotKey(
HWND hWnd, // window to receive hot-key notification
int id, // identifier of hot key
UINT fsModifiers, // key-modifier flags
UINT vk // virtual-key code
);
To catch any HotKey Message I use: ON_MESSAGE(WM_HOTKEY,OnHotKey) in the message map and this Callback Method to test it's functionality:
LRESULT OnHotKey(WPARAM wParam, LPARAM lParam)
{
if (wParam == MY_HOTKEY_KEY_CODE)
{
MessageBox(L"HotKey was pressed!");
return TRUE;
}
return FALSE;
}
When a HotKey is pressed it enters the OnHotKey Method and does not process the key normally. For example if I write some text in Notepad and press "O" as HotKey, the "O" wont append to my text but the Message "HotKey was pressed!" appears, which is nice.
But when I am in any Direct X Game and press my HotKey, it is not sent to my application. Also when typing something in a Direct X environment the HotKey just works as normal key.
Is Direct X binding all key inputs somehow? Is there a way to make Windows HotKeys work with Direct X environments?
I recently started coding in C++ and I am very new to it. (I code in Javascript, PHP, Java and Obj-C more often)
I'm practicing how to hook a message box and change its position. This is what I have in my .cpp file (after reading this SO post).
#include <iostream>
#pragma comment(lib,"User32.lib")
#include <windows.h>
HHOOK hhookCBTProc = 0;
LRESULT CALLBACK pfnCBTMsgBoxHook(int nCode, WPARAM wParam, LPARAM lParam){
if (nCode == HCBT_CREATEWND)
{
CREATESTRUCT *pcs = ((CBT_CREATEWND *)lParam)->lpcs;
if ((pcs->style & WS_DLGFRAME) || (pcs->style & WS_POPUP))
{
HWND hwnd = (HWND)wParam;
SetWindowPos(hwnd, HWND_TOP,130,122, 0, 0,SWP_NOSIZE);
}
}
return (CallNextHookEx(hhookCBTProc, nCode, wParam, lParam));
}
int main(void)
{
hhookCBTProc = SetWindowsHookEx(WH_CBT,pfnCBTMsgBoxHook,
0, GetCurrentThreadId());
int sResult = MessageBox ( NULL, "Hooked!", "oh my", MB_OK );
UnhookWindowsHookEx(hhookCBTProc);
return 0;
}
For some reason the position of the message box isn't changing. Where did it go wrong?
(I know I can create a customized window or dialog. But I am doing it this way because I want to learn how to hook a message box and where I did wrong.)
Firstly you should check in the debugger that your hook is actually being called, if you haven't already.
Secondly, at the time the HCBT_CREATEWND hook event is triggered, the window has only just been created - the system has yet to size and position it. It will do this with the values in the CREATESTRUCT after the hook returns - overriding your SetWindowPos call.
See the docs from MSDN on the lParam value for this particular hook event:
Specifies a long pointer to a CBT_CREATEWND structure containing
initialization parameters for the window. The parameters include the
coordinates and dimensions of the window. By changing these
parameters, a CBTProc hook procedure can set the initial size and
position of the window.
Therefore, the correct way to use this hook to change a window's position is to modify the values in the CREATESTRUCT directly.
Also note that it's quite possible that the dialog manager sizes and positions the window after creation, so if you find that this still isn't working for you, you may need to try watching for the HCBT_MOVESIZE event instead.
From the docs
At the time of the HCBT_CREATEWND notification, the window has been
created, but its final size and position may not have been determined
and its parent window may not have been established.
Maybe try hooking into CBT_ACTIVATE instead.
From inside my COM addin I create a dialog, and I then send messages to it from an external process. I use HWND_BROADCAST and RegisterWindowMessage.
But those messages are never received by the dialog proc of the COM addin. I know this because I log all the messages received by the dialog proc, and also the value returned by RegisterWindowMessage.
From the external process:
static UINT nCloseMessage = 0;
if (!nCloseMessage)
nCloseMessage = RegisterWindowMessage(_T("MyCloseMessage"));
PostMessage(HWND_BROADCAST, nCloseMessage, 0, 0);
From the COM add-in:
INT_PTR CALLBACK ProgressDialogProc(__in HWND hwndDlg,__in UINT uMsg,__in WPARAM wParam,__in LPARAM lParam)
{
static UINT nCloseMessage = 0;
if (!nCloseMessage)
nCloseMessage = RegisterWindowMessage(_T("MyCloseMessage"));
if (uMsg == nCloseMessage)
MessageBox(0,_T("Caught"),0,0);
return FALSE;
}
I found why I get this error, HWND_BROADCAST doesn't work when the dialog has a parent window.
Passing NULL to CreateDialog for the parent fixed the error.
How can I test if a button is being pressed ?
I am using EnumChildWindows() to enumerate the child windows of a given window, and one of the child window is a button, I want to test if that specific button is being pressed.
My code until know is:
BOOL CALLBACK MyEnumProc(HWND hwnd, LPARAM lParam)
{
char buffer[256];
GetWindowText(hwnd, buffer, sizeof(buffer));
cout << buffer << endl;
return true;
}
int main()
{
HWND hwnd = FindWindow(0, "Window to find");
EnumChildWindows(hwnd, MyEnumProc, 0);
return 0;
}
You can send the BM_GETSTATE message to the button control, if it is pressed the result will be
BST_PUSHED.
You need to inject a DLL into the process space, hook the window message loop (like you used to hand code a subclassed window in native Win32 API C code, Window Proc) (google-able) and listen to the actual messages.
All of this is ancient stuff for me, and I'm afraid that recent Windows versions (hopefully) made this a little bit more difficult to do.
That said, if you can get the application trusted with the right level of permissions, you should still be able to do this
I have a win 32 application written in c++ which sets the low level keyboard hook. now i want to sendInput to any app like word / notepad. how do i do this?
i have already done enough of using findwindow / sendmessage. for all these, i need to know edit controls. finding the edit control is very difficult.
since SendInput works for any windows application, i want to use it. the problem is i get a call to my callback function with the pressed key.
for e.g i pressed A and i want to send U+0BAF unicode character to the active applciation windows. in this case, assume it is notepad.
the problem is i get two characters U+0BAF and A in the notepad.
A is being sent because i am calling CallNextHookEx( NULL, nCode, wParam, lParam);
if i return 1 after sendInput, then nothing is sent to notepad.
any suggestion?
If I understood your problem correctly, you should ignore "injected" key events in your hook procedure, like this:
LRESULT CALLBACK
hook_proc( int code, WPARAM wParam, LPARAM lParam )
{
KBDLLHOOKSTRUCT* kbd = (KBDLLHOOKSTRUCT*)lParam;
// Ignore injected events
if (code < 0 || (kbd->flags & LLKHF_INJECTED)) {
return CallNextHookEx(kbdhook, code, wParam, lParam);
}
...
Update: additionally, you have to eat characters and notify some other routine for a character press through Windows messages.
Example:
...
// Pseudocode
if (kbd->vkCode is character) {
if (WM_KEYDOWN == wParam) {
PostMessage(mainwnd, WM_MY_KEYDOWN, kbd->vkCode, 0);
return 1; // eat the char, ie 'a'
}
}
return CallNextHookEx(kbdhook, code, wParam, lParam);
And, in some other module, you handle WM_MY_KEYDOWN:
ie, #define WM_MY_KEYDOWN (WM_USER + 1)
and call the appropriate routine that will generate new key events.