使用CursorLoader加载联系人信息

public class ContactsActivity extends AppCompatActivity implements SearchView.OnCloseListener, SearchView.OnQueryTextListener, LoaderManager.LoaderCallbacks<Cursor>, AdapterView.OnItemClickListener { // These are the Contacts rows that we will retrieve. static final String[] CONTACTS_SUMMARY_PROJECTION = new String[]{ ContactsContract.Contacts._ID, ContactsContract.Contacts.DISPLAY_NAME, ContactsContract.Contacts.CONTACT_STATUS, ContactsContract.Contacts.CONTACT_PRESENCE, ContactsContract.Contacts.PHOTO_ID, ContactsContract.Contacts.LOOKUP_KEY, }; private ListView mListView; private SearchView mSearchView; private SimpleCursorAdapter mAdapter; private String mCurFilter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_contacts); Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); toolbar.setLogo(R.mipmap.ic_launcher); toolbar.setTitle("Contacts"); setSupportActionBar(toolbar); mListView = (ListView) findViewById(R.id.lv); TextView emptyView = (TextView) findViewById(R.id.empty_view); mListView.setEmptyView(emptyView); setAdapter(); getSupportLoaderManager().initLoader(0, null, this); } private void setAdapter() { mAdapter = new SimpleCursorAdapter(this, android.R.layout.simple_list_item_2, null, new String[]{ContactsContract.Contacts.DISPLAY_NAME, ContactsContract.Contacts.PHOTO_ID}, new int[]{android.R.id.text1, android.R.id.text2}, 0); mListView.setAdapter(mAdapter); mListView.setOnItemClickListener(this); } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.menu_main, menu); MenuItem item = menu.findItem(R.id.search_view); mSearchView = (SearchView) MenuItemCompat.getActionView(item); // The normal SearchView doesn't clear its search text when // collapsed, so we will do this for it. mSearchView.setQuery("", false); mSearchView.setIconifiedByDefault(true); mSearchView.setOnCloseListener(this); mSearchView.setOnQueryTextListener(this); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { return super.onOptionsItemSelected(item); } @Override public boolean onClose() { if (!TextUtils.isEmpty(mSearchView.getQuery())) { mSearchView.setQuery(null, true); } return true; } @Override public boolean onQueryTextSubmit(String query) { //do nothing return true; } @Override public boolean onQueryTextChange(String newText) { // Called when the action bar search text has changed. Update // the search filter, and restart the loader to do a new query // with this filter. String newFilter = !TextUtils.isEmpty(newText) ? newText : null; // Don't do anything if the filter hasn't actually changed. // Prevents restarting the loader when restoring state. if (mCurFilter == null && newFilter == null) { return true; } if (mCurFilter != null && mCurFilter.equals(newFilter)) { return true; } mCurFilter = newFilter; getSupportLoaderManager().restartLoader(0, null, this); return true; } @Override public Loader<Cursor> onCreateLoader(int id, Bundle args) { // This is called when a new Loader needs to be created. This // sample only has one Loader, so we don't care about the ID. // First, pick the base URI to use depending on whether we are // currently filtering. Uri baseUri; if (mCurFilter != null) { baseUri = Uri.withAppendedPath(ContactsContract.Contacts.CONTENT_FILTER_URI, Uri.encode(mCurFilter)); } else { baseUri = ContactsContract.Contacts.CONTENT_URI; } // Now create and return a CursorLoader that will take care of // creating a Cursor for the data being displayed. String selection = "((" + ContactsContract.Contacts.DISPLAY_NAME + " NOTNULL) AND (" + ContactsContract.Contacts.HAS_PHONE_NUMBER + "=1) AND (" + ContactsContract.Contacts.DISPLAY_NAME + " != '' ))"; return new CursorLoader(ContactsActivity.this, baseUri, CONTACTS_SUMMARY_PROJECTION, selection, null, ContactsContract.Contacts.DISPLAY_NAME + " COLLATE LOCALIZED ASC" ); } @Override public void onLoadFinished(Loader<Cursor> loader, Cursor data) { if (loader.getId() == 0) { mAdapter.swapCursor(data); } } @Override public void onLoaderReset(Loader<Cursor> loader) { mAdapter.swapCursor(null); } //有问题--->根据id查询电话号码 @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { Cursor cursor = (Cursor) parent.getItemAtPosition(position); if (cursor == null) { return; } int contactsId = cursor.getInt(cursor.getColumnIndex(ContactsContract.Contacts._ID)); String name = cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME)); // query the corresponding phone number via contact_id, noting the relation between the // table {@link ContactsContract.Contacts} and the table {@link ContactsContract.CommonDataKind} Cursor c = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, new String[]{ContactsContract.CommonDataKinds.Phone.NUMBER}, ContactsContract.CommonDataKinds.Phone.CONTACT_ID + " LIKE ?", new String[]{String.valueOf(contactsId)}, null ); String phoneNumber = ""; try { if (c.moveToFirst()) { int numberColumn = c.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER); // a contact may have may phone number, so we need to fetch all. otherwise, you // can use{@link ContactsContract.CommonDataKinds.phone.TYPE.*} to limit the query //condition. do { phoneNumber += c.getString(numberColumn) + ","; } while (c.moveToNext()); Toast.makeText(ContactsActivity.this, name + "phone: " + phoneNumber, Toast.LENGTH_SHORT).show(); } } finally { if (c != null) { c.close(); } } } }