What is the best practice to update the page

[OliveInto]

I am currently using page's onappearing event to retrieve data from database and to get page updated when users navigate to the page. The page is registered as singleton since it is the main interface of my app, I do not want users to wait for page to be constructed every time. But I find if a user clicks a button to navigate to another page and backward, if the old page is in the async onappearing function, the event will not fire again during backward progress even when the user changed some data on the new page(I have to refresh the old page now).

My idea is to lock all the buttons' isenabled property when retrieving data, is there any better ways to solve the problem?