23 December 2013

Android show contact email addresses

So this is something in Android I thought would be really simple but quite frankly, wasn't. I want to get a list of all email addresses in my phone and display them in a list. If one is to use ContactsContract.CommonDataKinds.Email.CONTENT_URI without filter you basically get every email address you've ever emailed. Not ideal. I am (in this case) looking for only our saved Google contacts. We can do this query in the UI thread, which works fine but if you have several hundred contacts that'll kill the app. So we're going to use LoaderManager. First we setup out fragment:

public class FragmentMain extends Fragment implements LoaderManager.LoaderCallbacks{

 ArrayList mFriends = new ArrayList();


Now we need to setup our createLoader method to get the data and onLoadFinished to put the data into the UI. The selection here is very important as it limits the query to the visible contacts: String my_selection = ContactsContract.Contacts.IN_VISIBLE_GROUP + " = '1'";.
Next step is very simple, in the onLoadFinished we loop through the available data, adding each email address to an ArrayList.

 public Loader onCreateLoader(int arg0, Bundle arg1) {
  //Sort by email address no case
  final String my_sort_order = ContactsContract.CommonDataKinds.Email.DATA + " COLLATE NOCASE ASC";
  String my_selection = ContactsContract.Contacts.IN_VISIBLE_GROUP + " = '1'";
  String[] eproj = new String[]{
  Uri uri = android.provider.ContactsContract.CommonDataKinds.Email.CONTENT_URI;
  //Query all emails in contacts
  return new CursorLoader(getActivity(), uri, eproj, my_selection, null, my_sort_order);

 public void onLoadFinished(Loader arg0, Cursor data) {
  if (data != null && data.moveToFirst()) {
   //Loop through cursor
   while (!data.isAfterLast()) {
    //get Email address
    String myemail = data.getString(data.getColumnIndex(ContactsContract.CommonDataKinds.Email.DATA));
     //Add email to arrayList
  //load friends into ui

 public void onLoaderReset(Loader arg0) {
  //Not Used

Last but not least we load the data into our listview. Now you can of course, should you desire, create a custom Adapter and implement your own item view, but that's a blog post for another day.

 private void loadFriends(){
  //load arraylist into adapter.
  ArrayAdapter adapter = new ArrayAdapter(getActivity(), android.R.layout.simple_list_item_1, android.R.id.text1, mFriends);

Oh and one more thing, don't forget your permissions :)
<uses-permission android:name="android.permission.READ_CONTACTS" />

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