Click event viewpager subpages server requests involving refresh the page

Click event viewpager subpages server requests involving refresh the page

My subpages viewpager there a button click event, it sends a request to the server when clicked, if successful, would change the button's background does not change if it fails pop toast, ask to set the button's background in dealing with the results of how to do If the adapter is outside, then it can only be the first and last one, in the middle of the sub-pages are invalid<-! Main posts under Banner (D4) -><-! Posts under the main text (D5) ->