Re: [PATCH 0/2] MR8447: comctl32/listview: Test WM_PAINT with a subclassed header that paints without...

[Zhiyi Zhang (＠zhiyi)]

On Fri Jun 27 08:40:32 2025 +0000, Nikolay Sivov wrote:
> I see, so validating header rect reduces following erase region and
> preserves rendered header?

Yes. Normally, the original header implementation uses BeginPaint() when handling WM_PAINT, which automatically removes the update region. In this case, an application subclasses the header class and handles WM_PAINT without validating the update region. Thus, the header region is not preserved after calling BeginPaint(listview).