How to create appBar like on the picture. It'll be great if the appbar shows only when textbox is focus.appbar below keyboard
You can use the event GotFocus to show your appbar and LostFocus event to hide or collapse your appbar
GotFocus https://msdn.microsoft.com/en-us/library/windows/apps/windows.ui.xaml.uielement.gotfocus
LostFocus https://msdn.microsoft.com/en-us/library/windows/apps/windows.ui.xaml.uielement.lostfocus
Update : If you want to show your appbar when the textbox is focus you can use IsSticky= True
https://msdn.microsoft.com/en-us/library/windows/apps/windows.ui.xaml.controls.appbar.issticky.aspx
With this property your appbar will be visible even with the keyboard visible. I hope this helps!