How to update the `ListView` according to `ArrayList`?

Question

I have an array of contacts that I am constantly updating. I want my ListView to update with my contacts.

Should I use an Adapter for that? I

Answer 1

I usually have a method called setData(List data) in my Adapter. My Adapter is let's say in an Activity. When In my activity I obtain an updated array from wherever, I call setData() with the new array containing the updated array.

In my Adapter I have a field defined like: private List mItems. I use this field in the getCount() method of the Adapter to obtain the list items, basically I use this list to populate the ListView.

What I do in the setdata() is assign data to mItems and I call notifyDataSetchanged() which refreshes the ListView and this time it will use the newly set data values, so everything updates to the appropriate state.

UPDATE

I don't have quick access to an adapter for a ListView but the one below should do, it's for a ViewPager, but the principle is the same:

public class AdapterTweets extends PagerAdapter {
    private List mItems;

    // [...]

    @Override
    public int getCount() {
        return mItems == null ? 0 : mItems.size();
    }

    // [...]

    public void setData(List items) {
        mItems = items;
        notifyDataSetChanged();
    }
}