当用户调整我的对话框大小时，如何强制窗口不在我的对话框中重绘任何内容?

Here are some code excerpts that should get you most of the way:

LRESULT ResizeManager::WinProc(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam)
{
    switch (msg)
    {
    case WM_ENTERSIZEMOVE:
        m_bResizeOrMove = true;
        break;

    case WM_NCCALCSIZE:
        // The WM_NCCALCSIZE idea was given to me by John Knoeller: 
        // see: http://stackoverflow.com/questions/2165759/how-do-i-force-windows-not-to-redraw-anything-in-my-dialog-when-the-user-is-resiz
        // 
        // The default implementation is to simply return zero (0).
        //
        // The MSDN docs indicate that this causes Windows to automatically move all of the child controls to follow the client's origin
        // and experience shows that it bitblts the window's contents before we get a WM_SIZE.
        // Hence, our child controls have been moved, everything has been painted at its new position, then we get a WM_SIZE.
        //
        // Instead, we calculate the correct client rect for our new size or position, and simply tell windows to preserve this (don't repaint it)
        // and then we execute a new layout of our child controls during the WM_SIZE handler, using DeferWindowPos to ensure that everything
        // is moved, sized, and drawn in one go, minimizing any potential flicker (it has to be drawn once, over the top at its new layout, at a minimum).
        //
        // It is important to note that we must move all controls.  We short-circuit the normal Windows logic that moves our child controls for us.
        //
        // Other notes:
        //  Simply zeroing out the source and destination client rectangles (rgrc[1] and rgrc[2]) simply causes Windows 
        //  to invalidate the entire client area, exacerbating the flicker problem.
        //
        //  If we return anything but zero (0), we absolutely must have set up rgrc[0] to be the correct client rect for the new size / location
        //  otherwise Windows sees our client rect as being equal to our proposed window rect, and from that point forward we're missing our non-client frame

        // only override this if we're handling a resize or move (I am currently unaware of how to distinguish between them)
        // though it may be adequate to test for wparam != 0, as we are
        if (bool bCalcValidRects = wparam && m_bResizeOrMove)
        {
            NCCALCSIZE_PARAMS * nccs_params = (NCCALCSIZE_PARAMS *)lparam;

            // ask the base implementation to compute the client coordinates from the window coordinates (destination rect)
            m_ResizeHook.BaseProc(hwnd, msg, FALSE, (LPARAM)&nccs_params->rgrc[0]);

            // make the source & target the same (don't bitblt anything)
            // NOTE: we need the target to be the entire new client rectangle, because we want windows to perceive it as being valid (not in need of painting)
            nccs_params->rgrc[1] = nccs_params->rgrc[2];

            // we need to ensure that we tell windows to preserve the client area we specified
            // if I read the docs correctly, then no bitblt should occur (at the very least, its a benign bitblt since it is from/to the same place)
            return WVR_ALIGNLEFT|WVR_ALIGNTOP;
        }
        break;

    case WM_SIZE:
        ASSERT(m_bResizeOrMove);
        Resize(hwnd, LOWORD(lparam), HIWORD(lparam));
        break;

    case WM_EXITSIZEMOVE:
        m_bResizeOrMove = false;
        break;
    }

    return m_ResizeHook.BaseProc(hwnd, msg, wparam, lparam);
}

调整大小实际上是由 Resize() 成员完成的，如下所示:

// execute the resizing of all controls
void ResizeManager::Resize(HWND hwnd, long cx, long cy)
{
    // defer the moves & resizes for all visible controls
    HDWP hdwp = BeginDeferWindowPos(m_resizables.size());
    ASSERT(hdwp);

    // reposition everything without doing any drawing!
    for (ResizeAgentVector::const_iterator it = m_resizables.begin(), end = m_resizables.end(); it != end; ++it)
        VERIFY(hdwp == it->Reposition(hdwp, cx, cy));

    // now, do all of the moves & resizes at once
    VERIFY(EndDeferWindowPos(hdwp));
}

HDWP ResizeManager::ResizeAgent::Reposition(HDWP hdwp, long cx, long cy) const
{
    // can't very well move things that no longer exist
    if (!IsWindow(hwndControl))
        return hdwp;

    // calculate our new rect
    const long left   = IsFloatLeft()   ? cx - offset.left    : offset.left;
    const long right  = IsFloatRight()  ? cx - offset.right   : offset.right;
    const long top    = IsFloatTop()    ? cy - offset.top     : offset.top;
    const long bottom = IsFloatBottom() ? cy - offset.bottom  : offset.bottom;

    // compute height & width
    const long width = right - left;
    const long height = bottom - top;

    // we can defer it only if it is visible
    if (IsWindowVisible(hwndControl))
        return ::DeferWindowPos(hdwp, hwndControl, NULL, left, top, width, height, SWP_NOZORDER|SWP_NOACTIVATE);

    // do it immediately for an invisible window
    MoveWindow(hwndControl, left, top, width, height, FALSE);

    // indicate that the defer operation should still be valid
    return hdwp;
}