I am trying to create a simple dialog in MFC using Visual C++. My problem is that when I get the dialog on the screen and try to type in an Edit Box field, if I type the letter 'a' once, it appears in the edit box as 'aaaaaaaaaaa' (that's 12 a's). Furthermore, if I try to navigate around in the box using the arrow keys, the carat moves 12 characters at a time.
It's not just a display error, as the output from the editbox is still "aaaaaaaaaaaa".
I'd post code, but there's really none to post. I added the edit box using the Toolbox in Visual Studio and assigned a variable to it in my class so this isn't any sort of special edit box.
If anyone has any thoughts as to what might be happening it would be greatly appreciated. Unfortunately, I don't know where to begin.
Thank as always.
To debug this, add PreTranslateMessage function to your dialog, and see exactly how many times the keydown is being processed.
BOOL DialogName::PreTranslateMessage(MSG* pMsg)
{
if(pMsg->message==WM_KEYDOWN)
{
// TODO: see what is going on here
return TRUE; //do not dispatch this message, so keydown will have no effect
}
return CDialog::PreTranslateMessage(pMsg);
}
Are you capturing any events such as WM_KEYUP in your PreTranslateMessage() function or anywhere else in your app ?
If you have overridden the default handling for keyboard events, it might cause the symptoms you are seeing.
For some reason this brings back vague memories of early struggles with MFC. Have you looked for mutual recursion at all? I was forever doing something in one bit of the app that sent a message (unbeknown to me) that was picked up by another method that called the first method...
My guess is it's one of those smack the forehead ones; it gives me this nagging sense of deja vu that I can't make concrete.
If it's mutual recursion you should be able to see it in the call stack, if you can find the right place for a break point.
Is this happening for a fresh project, or can you recreate this problem in a fresh project?
It'll help discern whether it's something you've done in your code, or your install.
I installed service pack 2 in my WinXp 64 OS and the problem get solved for me :)
Related
I've searched this extensively, and the answer I came up with about 20 times is to use CWnd::EnableWindow(FALSE). Currently, I have:
GetDlgItem(myComboBox)->EnableWindow(FALSE);
Instead of disabling the ComboBox, now the entire Dialog doesn't show up, and since it's a modal dialog (or at least I'm guessing that's the reason), the entire program gets locked up because I can't close the dialog if it's not there.
Is there a way to disable editing to this box without making it disappear entirely; similar to what SetReadOnly() does for a CEdit?
Edit:
Suddenly, the syntax above started working the next morning. I'm still not entirely sure why it didn't work in the first place.
EnableWindow(FALSE) is the correct function to call but your syntax looks like it may be incorrect (but it's hard to say with such a minimal example).
Is myComboBox an instance of CComboBox? If so, I'd expect to see:
myComboBox.EnableWindow(FALSE);
or, using the associated resource ID:
((CComboBox*)GetDlgItem(IDC_MY_COMBO_BOX))->EnableWindow(FALSE);
Threading issues or duplicate resource ID's can also cause weird issues.
It seems you are trying to call EnableWindow() from a different thread than the dialog's
You could try this, and see if it works for you:
GetDlgItem(myComboBox)->PostMessage(WM_ENABLE, (WPARAM)FALSE);
(Maybe this is a beginner question for people experienced with Windows message queue handling and dialg boxes. Unfortunately this is not my area of expertise, so please be gracious to me.)
I have a quite simple C++ program in terms of user interface.
It should not be a real console program of several reasons, but it runs unattended.
It is basically a MFC stub without showing a window at all. But sometimes it shows message boxes like :
MessageBox("Question,"XX",MB_YESNO) or so.
The problem is, that, when two questions are posed after each other, sometimes Windows seems to save the mouse click or keyboard click or the user wanted to klick only once, but the hardware send two clicks. So the user has not real possibility to answer the second question, but yes or no is answered from the "ghost" click before.
(There is a word for it, but I don't know it in English. I hope, you got my point though.)
In the command line there is a fflush() for such things. How to handle it here?
I would even use a customized Messagebox, if I find somewhere ready code for it
(and I have not to write it :-)
But I thought, there might be an easy-to-use snippet to delete the message queue of the app before the next messagebox is shown. But all I know about Windows messages is that they exist ;-(
Can anybody help me?
Philm,
Message box is a modal window, hence it has own message loop. When message box is dismissed, its message does not exist, no mouse messages.
Mouse click messages are always posted to a window under the cursor, unless GetCapture is called.
From what you claim, you do not show any window, so no mouse messages posted in the que?
The only way to resolve your problem would be to debug your application or the test project that you write to duplicate this problem. Can you write it and post somewhere for downloading?
I am writing a program which interfaces with some testing equipment. I want the user to be able to press a button to stop the test, but only if the program is in focus. This is because they can be using their pc for other work at the same time. This is what I have now.
if ((GetAsyncKeyState(VK_ESCAPE) & 0x8000)&&(GetFocus() == FindWindow(NULL,TEXT("Window name")))){
break;
}
The problem is, the keypress is still determined even when the user is working on other programs. I also want this to happen without waiting for user input so the program can continue running(i realize I could probably use threading but I think that seems a little overkill in this case). If anybody knows a statement I can use in the second half of the IF statement that would be great, or even a different method altogether.
Thank you.
Wild guess this one. Maybe you could use the GetForegroundWindow function and check the handle against your test window handle. Possibly a better method is for your test window to handle the WM_KEYDOWN message. My understanding is that this message is only posted if the window has focus.
I have a game app that has the ability to go fullscreen and back to windowed when Alt-Enter is pressed. However, when it goes fullscreen, I get the following warning from DirectX:
DXGI Warning: IDXGISwapChain::Present: Fullscreen presentation inefficiencies incurred due to application not using IDXGISwapChain::ResizeBuffers appropriately, specifying a DXGI_MODE_DESC not available in IDXGIOutput::GetDisplayModeList, or not using DXGI_SWAP_CHAIN_FLAG_ALLOW_MODE_SWITCH.
I've already ruled out the second two possibilities through testing, so I know the only reasons left for the warning to pop up are either IDXGISwapChain::ResizeBuffers isn't being used right, or Windows is just bugged. Since I can't debug the 2nd possibility, I'm sticking with the ResizeBuffers problem. To debug this, I want to look at what happens when Alt-Enter is pressed going from windowed to fullscreen. However, the app does not seem to be calling my ResizeDXGIBuffers method; in fact, it seems that Alt-Enter is embedded into windows or DirectX somewhere, and I don't know how to find the chain of function calls that go off when it is pressed. EDIT: When my method is put in the WM_ACTIVATEAPP handler, it is called, but this is not what i meant. If i take it out of that message handler, the window STILL goes to fullscreen, even though I am not calling any functions to make the window fullscreen myself. So Alt+Enter must be automatically calling some internal function to do this.
So that is my question: Does anyone know what function is called by windows and/or DirectX 11 when Alt-Enter is pressed?
EDIT: As the tags for this question say, I am using DirectX 11 on a Windows machine. Specifically, Windows 7 64-bit.
EDIT 2: I now completely eat the Alt+Enter keystroke and manually store the state of Alt+Enter being pressed so that I know for certain only my code is being called. The warning I spoke of above persists, however. I am following the MSDN best practices as well, so I don't know where to go from here.
Try handling the WM_ACTIVATEAPP message.
I do not know which framework you use to create your windows, so I can't tell how to concretely handle this message.
After looking at the MSDN best practices page and re-working my code to reflect all of the practices described, the warning has disappeared. I hope this helps anyone else that has the same problem.
Also, thanks to Hans Passant for the link. I already fixed it by the time you posted it, but thanks anyways.
The application is of MFC. Sometimes I need to activate the window and display it at the topmost of the screen when it's deactivated, or hidden, or minimized. Here's what I did:
AfxGetMainWnd()->BringWindowToTop();
AfxGetMainWnd()->SetActiveWindow();
AfxGetMainWnd()->SetForegroundWindow();
if(AfxGetMainWnd()->IsIconic())
AfxGetMainWnd()->ShowWindow(SW_SHOWNORMAL);
else
AfxGetMainWnd()->ShowWindow(SW_SHOW);
AfxGetMainWnd()->UpdateWindow();
But I found sometimes the window was not activated and was still convered by window of other appliactions. Is there anything wrong with my approach? How should I fix this?
Thank you very much!
try
SetWindowPos(hwnd,HWND_TOPMOST,0,0,0,0,SWP_SHOWWINDOW);
it should work on all windows, since all windows have the same handle type.
Try also calling SetFocus on the window you want to show.
If that still doesn't work, or doesn't work 100% you could use a hacky workaround whereby you would launch a thread or window timer (timer's easier) which would periodically check to see whether or not the window that you want to be top most does indeed make it to the top of the order. Once this happens, possibly on the first iteration, you kill the thread or timer.
quantity, i see from your profile that you've asked 12 questions and accepted none. i find it hard to believe that none of the answers worked for you. Please consider going through the responses and marking ones that work as answers. 0% acceptance might cause folks to not care to answer your questions soon.
Cheers.