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Window title issues

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I recently started coding an editor for my game engine. This required me to take the game engine, which was originally one large .exe file, and split it into multiple .dll's so that the editor can have access to the engine's networking, map rendering, database access, and input handling. 

Now the window title wont show itself no matter what I do. I have not changed the window code at all during this rewrite.


1. Everything is single threaded.

2. The window is created in "engine_client.dll"

3. "engine_client.dll" is statically linked with the editor's executable.


The code I use to create the window (edited slightly to only show relevant code):

	// create window class
	WNDCLASSEX WindowClass;
	memset(&WindowClass, 0, sizeof(WNDCLASSEX));
	WindowClass.lpszClassName	= m_strWindowClassName.c_str();
	WindowClass.style			= CS_HREDRAW | CS_VREDRAW;
	WindowClass.cbSize			= sizeof(WNDCLASSEX);
	WindowClass.lpfnWndProc		= CreateWindowProc;
	WindowClass.hInstance		= m_hInstance;
	WindowClass.hIcon			= NULL; // LoadIcon(m_hInstance, (LPCTSTR)IDI_Logo);
	WindowClass.hIconSm			= NULL; // LoadIcon(m_hInstance, (LPCTSTR)IDI_Logo);
	if(RegisterClassEx(&WindowClass) == 0)
		m_ErrorLog.Print(std::string("[rdk::CWindow::Create::RegisterClassEx] ") + rdk::LastWindowsError() + "\n");
		return false;

	// set window size and style
	RECT	rect;
	DWORD	style;

		rect.left	= 0;
		rect.top	= 0;
		rect.right	= ulWidth;
		rect.bottom	= ulHeight;
		if(!AdjustWindowRect(&rect, style, false))
			m_ErrorLog.Print(std::string("[rdk::CWindow::Create::AdjustWindowRect] ") + rdk::LastWindowsError() + "\n");
			return false;

	// create and show the window
	m_hWnd = CreateWindow(m_strWindowClassName.c_str(),
						  (bFullscreen) ? 0 : CW_USEDEFAULT,
						  (bFullscreen) ? 0 : CW_USEDEFAULT,
						  (bFullscreen) ? rect.right : rect.right - rect.left,
						  (bFullscreen) ? rect.bottom : rect.bottom - rect.top,
	if(m_hWnd == NULL)
		m_ErrorLog.Print(std::string("[rdk::CWindow::Create::CreateWindow] ") + rdk::LastWindowsError() + "\n");
		return false;
	ShowWindow(m_hWnd, SW_SHOWNORMAL);

m_hInstance is set in the window class' constructor like this:

m_hInstance = GetModuleHandle(NULL);


Thanks in advance for any advice or help.

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You're probably doing something wrong elsewhere. Try SetWindowText( m_hWnd, "test title" ) after CreateWindow() and see if it succeeds. If not, see what GetLastError() returns. Are you using UNICODE strings?

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I just spent the last few hours converting my entire project to UNICODE to see if that would fix the problem (and because that was a long overdue change). That did not fix the problem. Placing a call to SetWindowText() did make the window text show up. The only code "between" CreateWindow() and the immediate call to SetWindowText() is CreateWindowProc(), which is a static function that links the CWindow object to the Windows HWND and assigns the proper WndProc. It handles the WM_NCCREATE message.


Contrary to my original post, I did in fact make a very minor change there.

	// if this window is being created...
	if(uiMsg == WM_NCCREATE)
		// get the window pointer passed in CreateWindow
		CWindow* pWindow = static_cast<CWindow*>((reinterpret_cast<CREATESTRUCT*>(lParam))->lpCreateParams);
		if(pWindow == nullptr)
			return FALSE;

		// assign the CWindow pointer as the user data associated with this window
		SetWindowLongPtr(hWnd, GWLP_USERDATA, reinterpret_cast<LONG_PTR>(pWindow));

		// now set the window proc
		SetWindowLongPtr(hWnd, GWLP_WNDPROC, reinterpret_cast<LONG_PTR>(&CWindow::StaticWindowProc));

		// return TRUE so that CreateWindow can continue creating the window
		return TRUE;
	return DefWindowProc(hWnd, uiMsg, wParam, lParam);


I commented out "return TRUE" (which was commented out originally) to allow DefWindowProc() to do what it needs to do with the message and now the window title shows up as expected.


Thanks Amr0, I would not have even checked without your advice.

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