android sqlite onresume（）oncreate（）

Question

我有一些写和读数据库的活动。 由于客户端必须在它们之间切换。 如果我仅将代码保留在onCreate中，则当活动重新回到屏幕上时，将不会更新不同的视图。 什么是确保活动集中注意力时确保所有数据都正确的最佳方法是什么？ 将evrything从onCreate（）移到onResume（）是否明智？

有水可以使它变得更好吗？

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();

    }





}

适配器

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

如果您尚未完成活动，则无需在onResume（）中编写所有内容

您应该只在onResume（）中编写此代码。

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

将CandidateAdapter定义为类变量。