Thread: DC is not pointing to my window!

I got a DC setup like this:

Code:

HDC hdcMainWin = GetDC(MainWindow);

and instead of pointing to the client area of MainWindow, it goes to the top-left corner of the screen.

I've included the .exe file to demonstrate.

Here is how I am creating the window, the loop, and the creation of the DC.

Code:

HWND MainWindow;
...
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE, LPSTR, int nCmdShow)
{
	{
		WNDCLASS wc;
		wc.cbClsExtra = 0;
		wc.cbWndExtra = 0;
		wc.hbrBackground = (HBRUSH)COLOR_WINDOW;
		wc.hCursor = LoadCursor(NULL, IDC_ARROW);
		wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
		wc.hInstance = hInstance;
		wc.lpfnWndProc = MainWndProc;
		wc.lpszClassName = "TED MainWindow";
		wc.lpszMenuName = NULL;
		wc.style = 0;

		if (!RegisterClass(&wc))
		{
			MessageBox(NULL, "Error registering window class!", "Error", MB_OK);
			return 1;
		}
	}

	if (!CreateWindowEx(0, "TED MainWindow", 
		"GDI Tile Engine Demo - Main Window", 
		WS_OVERLAPPED | WS_VISIBLE | WS_MINIMIZEBOX | WS_SYSMENU,
		CW_USEDEFAULT,	CW_USEDEFAULT,	640, 480, NULL, NULL, hInstance,
		NULL))
	{
		MessageBox(NULL, "Error creating main window!", "Error", MB_OK);
		return 1;
	}

	MSG msg;
        HDC hdcMainWin = GetDC(MainWindow);
	HBITMAP hbmBall = LoadBitmap(hInstance, MAKEINTRESOURCE(IDB_BITMAP1));


   while (TRUE)
	{
		if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
		{
			if (msg.message != WM_QUIT)
			{
				TranslateMessage(&msg);
				DispatchMessage(&msg);
			}
			else
				break;
		}
			tempX ++;
			tempY ++;
			graphics.BeginFrame(hdcMainWin);
			graphics.TransBlit(hbmBall, tempX, tempY);
			graphics.EndFrame();
	}
        ReleaseDC(MainWindow, hdcMainWin);
	return msg.wParam;
}