MFC Spin Control Buddy with Edit Control Error - c++

I've created all my controls through the dlg resource. I've added code to control the spin control and it works perfectly. However, if I want to directly change the value of the edit box by typing a value into it, the program crashes with no error message other than "exited with return value 13."
void CNuanceGuiPart2Dlg::OnEnChangeSignalDb(){
// TODO: If this is a RICHEDIT control, the control will not
// send this notification unless you override the CDialogEx::OnInitDialog()
// function and call CRichEditCtrl().SetEventMask()
// with the ENM_CHANGE flag ORed into the mask.
// TODO: Add your control notification handler code here
}
If I am to add any code into the above block that contains an UpdateData call or manipulates a CEdit/CSpinControl object, it gives me a debug assert at wincore2.cpp, Line 128.
EDIT:
So I figured out that the function is being called too soon when the code first runs. If I wrap the entire function that is being mapped from ON_EN_CHANGE with a if(gui_start), with gui_Start signaling when CDialog::OnInitDialog() has been executed, any updates to the GUI can run fine - I don't even get a debug runtime error. My question is: anyway I can do this without the gui_Start? Why is the ON_EN_CHANGE for this particular edit box being called so soon? Does it have to do with the spin control? Thanks in advance.

Related

How to sync a Progress Control with a set of data which is loading in a Dialog Box in Visual C++

I'm trying to add a progress control in my dialogs, that will step upon every iteration of a loop until completion. I've never played around with progress controls before, so I'm totally clueless as to where I should start. I've added a progress control resource view into my dialog, but it just shows up as an empty progress control. I'd like to have the progress control dynamically appear/update when after pressing a button an image from somewhere stars being loaded.
I am trying to add a progress control on a dialog box in Visual c++ environment.
After adding this tool the following code added to main.cpp :
void CPanoramicsampleDlg::OnNMCustomdrawProgress1(NMHDR *pNMHDR, LRESULT *pResult){
}
I can show procedure of loading in a Text control as follow:
sprintf_s(pack1,"Data%d%%",Event);
::SetWindowText(GetDlgItem(IDC_Static)->m_hWnd,pack1);
so in this way I can see loading process as %d in a text window but I don't know how to show loading procedure by progress control and how and where to define range or even progress bar handle for this progress control so on.
finally I would like to know is there any function for progress control for example:
::EnableWindow(GetDlgItem(IDC_Progress1)->m_hWnd);
You should first add a variable for the control, by right-clicking on the progress bar in the dialog editor, and choosing Add Variable... Your dialog class will then have an instance of a CProgressCtrl class on which you can then call the members that IInspectable has mentioned in his answer. Delete the OnNMCustomdrawProgress1 handler, you don't need it.
e.g.
m_progressCtrl.EnableWindow(TRUE);
m_progressCtrl.SetRange(0, 100);
m_progressCtrl.SetPos(75);
Then whatever that eventParam1 value is that you mention, proportion it between your start and stop value, and call SetPos with it.
Update after comment:
Do the SetRange() in the OnInitDialog() function. If you don't already have an OnInitDialog you need to override it, follow the instructions in the accepted answer of this question to do it.
VS 2008, MFC: add OnInitDialog - how?
As for where you put the SetPos(): You describe that you can already track loading progress in a text control using some or other eventParam1. That sounds like a handler or callback from what ever loading you're doing, and that is where you will instead SetPos() on the progress bar instance.
The CProgressCtrl Class provides the following members that you will have to use:
CProgressCtrl::SetRange: Allows you to set lower and upper bound. These values ideally reflect your starting state and finishing condition.
CProgressCtrl::SetPos: Used to update the current position. You would update the current position where you used to output progress in your edit control.
As an alternative to calling CProgressCtrl::SetPos with an explicit position value, you can set a step increment, calling CProgressCtrl::SetStep, and update the control with a call to CProgressCtrl::StepIt. If you know the step increment ahead of time, this is an easier way to go about updating the current position.
Additional information is available at the MSDN: Using CProgressCtrl.

Windows phone C++

I'm writing simple application for WP 8.1 using C++/cx. My problem starts when I'm trying to do something in some event. For example if I create simple button event "tapped" and I want to do something inside for example change the color of the button background, it doesn't execute in the correct time. I mean that for the code below it will first execute Somefunction() and then change the color of the button.Same happens for example when I try to show message box using message dialog and ShowAsync function.
but->Background = ref new SolidColorBrush(Windows::UI::Colors::Red);
Somefunciton();
You have the background change and the function call in the same function and that function gets executed on one thread blocking it. This thread happens to be the UI thread which gets blocked for the time of your function execution. So you set the button background but the actual change will be applied only when the UI thread could run the render function and it will be able to do it only after your function call ends.
So in terms of program execution the button background gets updated before the call to Somefunciton();. But visual changes are delayed until after the function call is completed so you might think that Somefunciton(); gets called before the background is set which is not the case.

Getting results from a non thread blocking message box?

Generally, message boxes work like this:
if(ShowMessageBox("Title","Text",MB_YES_NO) == MB_YES)
{
//the user responded yes
}
However, I'm working on a game where I have made the gui system, and when a messagebox is shown, there is still animation happening in the background so I cannot simply block the thread, the animation would stop.
Right now, the way it works is to show the message box, an IMessageHandler* must be provided and it is called with the dialog result.
I'm wondering if I'm overlooking something. Is there a better way to do this that might resemble more how it is usually done. How might other games approach it?
Thanks
There are multiple options, e.g...
Create a View-Model class that the message box reads from (title, message, button text) and writes to (result prior to closing), pass the VM to your message box before displaying it, then read result from VM after close.
(A better technique would to use a command pattern or place an event on the message box instead of passing VM to message box, then within command/event handler update VM).
Use a command pattern or an event to pass result from message box (prior to close) directly to caller (or to view model).
Use a show dialog style call to message box (blocking), however, do that on a separate thread, then write results to a place where main thread can read from.

Globally intercept window movement

I am having trouble getting a global system hook to work. I want to be notified whenever a window is moving, as early as possible, and change the window size. This means the CBT hook HCBT_MOVESIZE won't cut it, it only happens after the window has been moved. I want to hook the actual movement of the window, and be able to change the window size during the move.
The hooks are set from a DLL, and the callback function is within that DLL. This is what I've tried.
WH_CALLWNDPROC. It does alert me when a window is moved (WM_MOVING is received for windows from other applications), but I cannot change the contents of the message.
WH_CALLWNDPROCRET Same as WH_CALLWNDPROC.
CBT hook HCBT_MOVESIZE. Event happens to late.
WH_GETMESSAGE. Never receive WM_MOVE, WM_MOVING or WM_WINDOWPOSCHANGING. This hook would allow me to change the messages.
Update: Windows event hooks seem to allow me to capture it:
hWinEventHook = SetWinEventHook(EVENT_SYSTEM_MOVESIZESTART,
EVENT_SYSTEM_MOVESIZEEND, NULL, WinEventProc,
0, 0, WINEVENT_OUTOFCONTEXT | WINEVENT_SKIPOWNPROCESS);
However, this creates a different problem: changing the size of the window using SetWindowPos() does not work (it changes size alright, but immediately changes back to its previous size), even though I use SWP_NOSENDCHANGING. Ideas?
Update 2: Subclassing seems to work, however Visual Studio crashes after each program run (so does a lot of other windows). It works well if I place breakpoints and walk through the "unsubclassing", but not when I let the program run by itself. Ideas?
I have a CBT hook (it was there from earlier), and whenever HCBT_ACTIVATE is sent for a new window, I remove any previous subclassing using SetWindowLongPtr() (this has to run on 64-bit as well), and then subclass the new window. If I put a breakpoint anywhere, and immediately resume the session when it breaks, everything works fine. However, when I do not have any breakpoints, Visual Studio crashes when the program exits.
Hm, I would've thought that HCBT_MOVESIZE is precisely what you want, given that the MSDN says this about CBT hooks:
The system calls this function before activating, creating, destroying,
minimizing, maximizing, moving, or sizing a window.
and in particular:
HCBT_MOVESIZE
A window is about to be moved or sized.
(these quotes were taken from http://msdn.microsoft.com/en-us/library/ms644977%28VS.85%29.aspx)
...so I'd have thought that you get the HCBT_MOVESIZE call in time. The hook function which handles HCBT_MOVESIZE is also allowed to return an integer so that the system can determine whether the operation is allowed or should be prevented. Hence, given that the HCBT_MOVESIZE hook should get an option to prevent the operation, I'd say it's called before the move event occurred.
Are you really sure the hook function is called after the move event? If you do a GetWindowRect call on the particular handle within your hook function, does the returned rect equal the rectangle which is passed to the hook function?
Hooks are pretty heavy. You only want to use them when you absolutely have to.
That said, you could use one of the basic hooks simply as a way to get into the process. Once in the process, you could subclass the window you're interested in and handle the sizing messages in your subclass proc rather than trying to catch everything at the hook level.
Depending on what you want to do in response to the resize, you might need some interprocess communication.

How to update a dialog box via SetDlgItemText within a function and have it take effect immediately in windows?

If I call SetDlgItemText() to update the value of a dialog text it seems to only be updated when the function returns. I'm using it to update a status message informing the user of the current progress mid function so I would like it to be updated immediately.
If this can not be done, is there something else I can do that would perform the same results?
Any help would be appreciated.
Thanks.
I think Processing function is not allowing to call the OnPaint message of the window to which you are setting the message. You can move the processing function to a thread so that main thread handles the UI messages.