Create TabletModeController.cs by referring to the following. https://docs.microsoft.com/en-us/windows-hardware/drivers/gpiobtn/laptop-slate-mode-toggling-between-states

This sln/csproj is task tray application that folowing function.

• Change tablet mode and rotate display, by the shortcut key.
• Change tablet mode and rotate display, by the display flaps detect. (Display flaps detection is hardware dependence.)