Under MFC, an unexpected phenomenon occurred. Can this be considered a bug for Microsoft?

Microsoft’s own products, Visual Studio and Office, do not use MFC as an interface library. They all use Windows rendering technology. What the outside world knows is DirectUI: The source code that DirectUI can currently find is: https://github.com/duilib/duilib This technology has high rendering efficiency and occupies less system resources. DirectUI was developed between Windows 2000 and Windows XP as an experimental visualization framework. DirectUI predates Avalon (also known as WinFX and later WPF), and it can be seen that there are many similarities between DirectUI and Avalon. The developers who wrote DirectUI joined the Avalon team when they were established, so the spiritual connection is not surprising. DirectUI can also be seen as a precursor to Avalon’s simpler and weaker functionality. Due to the experimental nature of DirectUI, many processes surrounding it have not been formalized. Especially, DirectUI is quite free to fork and there is no unified version. Windows XP DirectUI: Windows XP uses relatively earlier versions of DirectUI in three places: the Explorer Task Panel, Welcome Screen, and Add or Remove Programs Control Panel. MSN Explorer: Before Windows XP, the code was forked and copied to the MSN team, who used it to run and generate MSN Explorer. Messenger: The Messenger team obtained a copy of DirectUI from the MSN Explorer team and made significant changes, especially in terms of accessibility. Office NetUI: At the same time, a branch version of DirectUI was handed over to the Office team, who used it as the foundation for the framework they called NetUI. Office FlexUI: Office personnel further developed NetUI and created FlexUI. Windows Vista DirectUI: Windows Vista DirectUI starts with Windows XP DirectUI and merges into the selected section of Messenger DirectUI. Windows 7 Ribbon: The Windows 7 ribbon is based on the Office ribbon and is therefore a branch of Office NetUI/FlexUI. Windows LiveDUI: The Live team developed their own DirectUI fork version and released it starting from Wave 4.
“Source=1def8aca”/>The DirectUI family lineage of Office should now be FlexUI, and Visual Studio is also a similar technology. This is easy to verify. If you use the SPYXX tool to test these two products, the entire interface only has one Windows handle HWND. If it is written in the MFC interface library,. NET WinForm, or DELPHI, then each control is a form with a handle. Spy++Introduction – Visual Studio (Windows) In fact, Microsoft’s own products have long abandoned the MFC set of big and heavy things, and this thing happened more than a decade ago. “Visual Studio 2010 I made a big change to the interface library, and Office even started earlier. This thing is basically the GacUI written by your wheel brother, who is on the Office team. In fact, programmers who still have feelings for MFC should pay attention to WTL: Windows Template Library (WTL), which is exquisitely written and is a pure template library implementation.