Can't change position of button - c++

Question

In a C++ app I create a button using CreateWindowEx and later try to change its position using SetWindowPos, but the button doesn't appear where I want it.
What's interesting is that when I resize the window (with the mouse, not programatically), I can see for a split second a blank silhouette the same size of the button where the button is supposed to appear. This must be because I also call SetWindowPos in response to window resizing events. However the actual button stays at the same location. I'd post a screenshot but for some reason the silhouette never shows up in screenshots.
This is the code that changes the X position (the code that changes the Y position is almost identical):
HRESULT Control::put_Left(float left)
{
RECT windowRect;
::GetWindowRect(m_hWnd, &windowRect);
if (m_isTopLevel)
{
BOOL bResult = ::SetWindowPos(
m_hWnd,
nullptr,
static_cast<int>(DesktopDpi::GetInstance().DipsToPixelsX(left)),
windowRect.top,
0,
0,
SWP_NOSIZE | SWP_NOZORDER | SWP_NOREPOSITION
);
if (!bResult)
return HRESULT_FROM_WIN32(::GetLastError());
}
else
{
// NOTE: for a button this is the code that will execute, because a
// button is not a top-level window
HWND hWndParent = ::GetParent(m_hWnd);
if (hWndParent == nullptr)
return HRESULT_FROM_WIN32(::GetLastError());
POINT parentPos = {0, 0};
if (!::ClientToScreen(hWndParent, &parentPos))
return E_FAIL;
BOOL bResult = ::SetWindowPos(
m_hWnd,
nullptr,
static_cast<int>(DesktopDpi::GetInstance().DipsToPixelsX(left)),
windowRect.top - parentPos.y,
0,
0,
SWP_NOSIZE | SWP_NOZORDER | SWP_NOREPOSITION
);
if (!bResult)
return HRESULT_FROM_WIN32(::GetLastError());
}
return S_OK;
}

Answer 1

Are you sure the parent of the button isn't moving it back to the old position when it handles WM_SIZE? It sure sounds like it from your description.