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![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(208, 90%, 30%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EV%3C/text%3E%3C/svg%3E)
This is my gui structure (pseudocode):
WNDCLASS.lpfnWndProc = WindowProcessMessages; // all my messages are processed here
HWND main = CreateWindow() //this is my main window, a 500x500 box, messages are processed in WindowProcessMessages
HWND groupBox = CreateWindow(BS_GROUPBOX, main) //groupbox is a child of main
HWND button = CreateWindow("Button", groupbox) //button is a child of groupbox
However when I try to catch button click event in WindowProcessMessages It doesn't work. So I tried to use SetWindowLongPtr(button, GWLP_WNDPROC, WindowProcessMessages). Now the button doesn't even show up! Any ideas? or is this simply not possible and I misunderstood SetWindowLongPtr with GWLP_WNDPROC?
My goal is to have button click event in WindowProcessMessages. Thanks!
So it means that the only way button can pass message is to do call callwindowproc() inside groupbox? I'd like to avoid this if possible and go straight to the main wndproc without going through groupbox first.
If you really want to subclass a control (like groupbox) in some appropriate circumstances, I think that you should use SetWindowSubclass, providing a corresponding specialised procedure (https://learn.microsoft.com/en-us/windows/win32/controls/subclassing-overview).
my wndproc only has 4 parameters WindowProcessMessages(HWND hwnd, UINT msg, WPARAM param, LPARAM lparam). While SetWindowSubclass expects 6 (adding UINT_PTR uIdSubclass, DWORD_PTR dwRefData). Using SetWindowSubclass on WindowProcessMessages return a heap corruption at
default:
return DefWindowProc(hwnd, msg, param, lparam);
Using that function doesn't feel correct.
I think that you are not using the functions correctly.
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Groupbox is static control
Your button must be a child of main window.
HWND button = CreateWindow("Button", main) //button is not a child of groupbox
https://stpetrus27.wordpress.com/2018/06/04/vc-vc-dialog-without-the-resource-file/
This is not my goal, the button position must be relative to the groupbox because it's the child, but I want the message to go straight to main wndproc
Petrus is right
A Button is never a child of a Group Box, but a child of the main window
PetrusKIM is right
A Button is never a child of a Group Box
But it can be a child of a group box. Or is this not allowed in windows? My UI will have a tree-like structure. e.g
groupbox will have a button in it where the position is relative to the parent (groupbox). Not possible?
Everything is possible, but it has no sense to make a Button as child of another Button (a Group Box being a Button)...
It seems to me that you are making this much more complicated than it has to be.
You know the position and size of the GroupBox control when you create it. Subsequently, when calling CreateWindow for the Button control you can easily position it relative to the Groupbox control since you already have the position/size of the GroupBox. Setting the parent window of the Button control to the main window ensures that it receives the button's notification messages.
Proper positioning achieved, no subclassing required.
Possible but Not Easy!
You will create your own "User Control" with subclassing.
Conceptually, see the User Contrl in .NET Framework (WINFORMS)
https://learn.microsoft.com/en-us/dotnet/api/system.windows.forms.usercontrol?view=net-5.0
or Use the 3rd Party Control Like "GuiToolkit MFC Extension" or MFCMFC Class.