Update UI from a file on activity create

hi,

I'm trying to present a checkbox that the status of it is kept in a file, when the actifity is created for the first time, I read the status,

how can I update the checkbox checked member ?
updating it must happen after activity.loadLayout cause before that the checkbox does not exist right ?
and thats too late, it alreday present the checkbox , if I update after the loadLayout happen, it does not change the presentation layer, even if I call invalidate

thanks