When pressing Back the previous Listview has gone is empty

Question

At first, I have a listview in layout1 to list the members' name which stored in a sqlite file. When I click one of the names, it goes to layout2 to show the detil imformation. But when I click a button I designed to back to layout1, layout1 will be empty and dark. Listview has gone. How can I keep the layout1 alive ??