Update ViewPager dynamically?

Question

I can\'t update the content in ViewPager.

What is the correct usage of methods instantiateItem() and getItem() in FragmentPagerAdapter class?

I was using onl

Answer 1

I use EventBus library to update Fragment content in ViewPager. The logic is simple, just like document of EventBus how to do. It is no need to control FragmentPagerAdapter instance. The code is here:

1: Define events

Define which message which is needed to update.

public class UpdateCountEvent {
    public final int count;

    public UpdateCountEvent(int count) {
        this.count = count;
    }
}

2.Prepare subscribers

Write below code in the Fragment which is needed update.

@Override
public void onStart() {
    super.onStart();
    EventBus.getDefault().register(this);
}

@Override
public void onStop() {
    EventBus.getDefault().unregister(this);  
    super.onStop();
}

public void onEvent(UpdateCountEvent event) {//get update message
    Toast.makeText(getActivity(), event.count, Toast.LENGTH_SHORT).show();
}

3.Post events

Write below code in other Activity or other Fragment which needs to update parameter

//input update message
EventBus.getDefault().post(new UpdateCountEvent(count));