Win32 C++ Create a Window and Procedure Within a Class

Question

Pre-Text/ Question

I am trying to make a fairly simple tool to help debug variable values. For it to be completely self contained within the class i

Answer 1

Your window procedure is called during CreateWindow. You pass hWindow to DefWindowProc, but hWindow is only set after CreateWindow returns - so you pass DefWindowProc a garbage window handle.

I don't see a nice way to do it. You could set hWindow inside the window procedure, by changing WindowProc to:

LRESULT WindowProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)

(added the hwnd parameter), changing the call to:

return view->WindowProc(hwnd, message, wParam, lParam);

creating the window like this:

hWindow = NULL;
hWindow = CreateWindow(..., hInst, this);
if (hWindow == NULL)
    return -1;

(the first assignment is to make sure hWindow is initialized; the second one is in case CreateWindow fails after calling the window procedure), and adding this at the start of WindowProc:

if(!this->hWindow)
    this->hWindow = hwnd;