Question

I have several activities that write and read to database. As client has to switch between them. If i leave code just in onCreate, different views will not be updated when activity is broght back to screen. What is the best way to ensure that all data is apdated when activity gets focus?
Is it wise to move evrything from onCreate() to onResume() ?

is there wat to make it better?

public class InboxActivity extends ListActivity {

    List<Candidate> candidates;
    private DatabaseHandler db;
    private CandidateAdapter adapter;
    private ListView lvMain;
    public void onDestroy(){
        if (db != null)
            db.close();

        super.onDestroy();
        //db.close();
    }
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.inbox_list);
        db = new DatabaseHandler(this);
        candidates = db.getAllCandidates(1);
        db.close();
        adapter = new CandidateAdapter(this,(ArrayList) candidates);
        lvMain = getListView();
        lvMain.setAdapter(adapter);
        lvMain.setOnItemClickListener(new OnItemClickListener() {

            public void onItemClick(AdapterView<?> parent, View view,
                    int position, long id) {

                String name = ((TextView) view.findViewById(R.id.from)).getText().toString();
                Log.d("Name ", name);


                Intent in = new Intent(getApplicationContext(), SingleMenuItemActivity.class);
                in.putExtra("name", name);
                Log.d("Starting activity ", "Yeah ");
                startActivity(in);

            }
        });
    }
    public void onResume(){
        super.onResume();
        db = new DatabaseHandler(this);
        candidates = db.getAllCandidates(1);
        db.close();
        adapter = new CandidateAdapter(this,(ArrayList) candidates);
        lvMain = getListView();
        lvMain.setAdapter(adapter);
        adapter.notifyDataSetChanged();

    }





}

adapter

public class CandidateAdapter extends BaseAdapter{
    Context ctx;
    LayoutInflater lInflater;
    ArrayList<Candidate> objects;
    CandidateAdapter(Context context, ArrayList<Candidate> candidates) {
            ctx = context;
            objects = candidates;
            lInflater = (LayoutInflater) ctx
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
          }
    public int getCount() {
        return objects.size();
      }
    public Object getItem(int position) {
        return objects.get(position);
      }
    public long getItemId(int position) {
        return position;
      }
    Candidate getCandidate(int position) {
        return ((Candidate) getItem(position));
      }
    public View getView(int position, View convertView, ViewGroup parent) {
        // используем созданные, но не используемые view
        View view = convertView;
        if (view == null) {
          view = lInflater.inflate(R.layout.inbox_list_item, parent, false);
        }
        Candidate p = getCandidate(position);
        ((TextView) view.findViewById(R.id.from)).setText(p.get_name());
        ((TextView) view.findViewById(R.id.subject)).setText(p.get_office());
        ((RatingBar) view.findViewById(R.id.rateindicator)).setRating(p.get_ranking());
        int loader = R.drawable.loader;


        ImageView image = (ImageView) view.findViewById(R.id.photo);


        String image_url = p.get_photograph();


        ImageLoader imgLoader = new ImageLoader(ctx);


        imgLoader.DisplayImage(image_url, loader, image);
        return view;
    }



}

Answer 1

If you are not finishing your activity, than you no need to write all thing in onResume()

you should write just this in onResume().

 public void onResume(){
     adapter = new CandidateAdapter(this,(ArrayList) candidates);
    lvMain.setAdapter(adapter);
    adapter.notifyDataSetChanged()
}

define your CandidateAdapter as a class variable.