What context Should be Use in setUserVisibleHint Method

问题

Because All fragment loaded with together In Pager Sliding tab , I need to use setUserVisibleHint() for laoding that fragment selected . I have Problem with Context in the setUserVisibleHint() method : It raised NPE Exception when I use getActivity for my Context. Thanks

回答1:

Because getActivity will return null before fragment attached to Activity you need check this value will null or check fragment attached to activity or after onActivityActtached function.

@Override
public void setUserVisibleHint(boolean isVisibleToUser) {
    super.setUserVisibleHint(isVisibleToUser);
    if (getActivity() != null) {
       //do something
    }
} 

//or 
 boolean isAttached = false;
 @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
        isAttached = true;
    }

@Override
public void setUserVisibleHint(boolean isVisibleToUser) {
    super.setUserVisibleHint(isVisibleToUser);
    if (isAttached) {
       //do something
    }
} 

回答2:

Its better to use newInstance Method and put your String over there. And then in fragment use

getArguments().getString("KEY")

来源：https://stackoverflow.com/questions/37523223/what-context-should-be-use-in-setuservisiblehint-method