无需让用户等待即可在android中加载大量数据的最佳方法

Question

I'm working in an application that read phone contacts and use them in my application (Call history, Favorite contacts and All contacts).

My UI consist of tab host control and user can swap between them, as I want my data to be shared across all my activities and also to be saved in only one place.

So I have created a singleton class called data controller, and when I open the application I show loading screen until all data loaded.

The problem now that user is complaining because of waiting a lot of time about (1 minute) every time they open the application when he has a very large amount of contacts, so how can I optimize my code in a good way?

EDIT

This is the method that I'm using to get all contacts:

public static ArrayList<ContactInfo> getAllContactWithNumberAndNameAndPhoto(
            Context context, boolean starred) {

        ArrayList<ContactInfo> retList = new ArrayList<ContactInfo>();

        ContentResolver cr = context.getContentResolver();

        Cursor cur = null;
        if (starred == true) {
            cur = cr.query(ContactsContract.Contacts.CONTENT_URI, null,
                    "starred=?", new String[] { "1" }, null);
        } else {

            cur = cr.query(ContactsContract.Contacts.CONTENT_URI, null, null,
                    null, null);
        }
        if (cur.getCount() > 0) {
            while (cur.moveToNext()) {

                ContactInfo item = new ContactInfo();
                String id = cur.getString(cur
                        .getColumnIndex(ContactsContract.Contacts._ID));
                String name = cur
                        .getString(cur
                                .getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));
                Uri photo = PhoneUtils.getPhotoUriFromID(context, id);
                String starredValue = cur.getString(cur
                        .getColumnIndex(ContactsContract.Contacts.STARRED));
                boolean isFav = false;
                if (starredValue.equals("1"))
                    isFav = true;

                if (Integer
                        .parseInt(cur.getString(cur
                                .getColumnIndex(ContactsContract.Contacts.HAS_PHONE_NUMBER))) > 0) {
                    Cursor pCur = cr.query(
                            ContactsContract.CommonDataKinds.Phone.CONTENT_URI,
                            null,
                            ContactsContract.CommonDataKinds.Phone.CONTACT_ID
                                    + " = ?", new String[] { id }, null);
                    while (pCur.moveToNext()) {

                        String phoneNo = pCur
                                .getString(pCur
                                        .getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
                        item.addPhone(removeCharactersFromPhoneNumber(phoneNo));
                    }
                    pCur.close();

                    if (photo != null) {

                        item.setPhoto(photo.toString());
                    }

                    item.setName(name);
                    item.setFavorite(isFav);
                    item.setRecent(false);

                    retList.add(item);
                }
            }
            cur.close();
        }

        return retList;
    }

Please let me know if I can optimize this method.

Answer 1

Im surprised it takes that long to load the contacts from the device.

Have you profiled the app to see where the time is actually spent? Something seems wrong here.

If it truly takes that long to load from the system providers (due to the OS) you could cache the results (ie put in your own SQL db) so you can load quickly on each app visit (< 1 sec) and refresh from device in the background.

Answer 2

I guess that the bottleneck of your method is photo loading. Try to load everything except photos, and then show your activity, concurrently loading photos.

Also you can try to create your own app table that contains just the data you need. So you'll do less selects while loading contacts. But you would have to synchronize your table. You can do so concurrently.