Problem facing while changing the orientation of master detail page.

Hi, I am developing a xamarin forms app.
I want my Master(Menu List) page of MasterDetailPage to be open both in landscape and portrait mode once it gets fired.
It should be open untill user intetionally hide it by sliding it back.
Currnetly Master page is getting hide while coming from landscape to portrait mode and vice versa.Kindly help me out.