Приложение WinAPI с классом С++

LRESULT CALLBACK WndProc(HWND hwnd, UINT iMsg, WPARAM wParam, LPARAM lParam)

class CDmcListView
{
..
    private:
 
        static              LRESULT CALLBACK _wndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam);
};

LRESULT CALLBACK CDmcListView::_wndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
 
    static CDmcListView *plv = NULL;
    PAINTSTRUCT ps;
    HDC hdc;
 
    static long nItem;
    static RECT r;
 
    switch (message)
    {
        case WM_CREATE:
            plv = (CDmcListView*)((LPCREATESTRUCT)lParam)->lpCreateParams;
            plv->_lp.hwnd = hwnd;
            SetWindowLongPtr(hwnd, GWLP_USERDATA, (LONG)plv);
 
            break;
 
        case WM_PAINT:
            plv = (CDmcListView*) GetWindowLongPtr(hwnd, GWLP_USERDATA);
 
            if (plv == NULL || !plv->_initialized)
                break;
 
            hdc = BeginPaint(hwnd, &ps);
            plv->_lp.hdc = hdc;
            plv->onPaintList();
            EndPaint(hwnd, &ps);
 
            break;
 
 
 
        default:
            plv = (CDmcListView*) GetWindowLongPtr(hwnd, GWLP_USERDATA);
            return DefWindowProc(hwnd, message, wParam, lParam);
 
    }
 
    return 0;
 
}

int CDmcListView::create(CDmcList *list, unsigned int mode, HWND parentWnd, unsigned long id, int x, int y, int width, int height, HINSTANCE hInstance)
..
wcex.lpfnWndProc    = _wndProc;
..