Hi Li Minglin,
感谢在MSDN论坛发帖。
通过在我的vs2015 update3上测试,该问题可以通过关闭并重新打开MyForm.h解决。

如果你没有成功或者还有疑问,可以connect Microsoft寻求更好的帮助。
Best Regards,
Sera Yu
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