Use WS_EX_TOPMOST style. Window should be created with CreateWindowEx function, dwExStyle parameter should contain WS_EX_TOPMOST style.
To change extended style of existing window use SetWindowLong with
Displaying an arrayList in a listView using the default adapter is rarely the best solution. To get full control of your display data, and to be able to refresh it after editing, requires the use of a custom adapter.