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Android Build a Self-Destructing Message Android App Relating Users in Parse.com Executing a Query

Eilon Krauthammer
Eilon Krauthammer
4,768 Points
Posted by Eilon Krauthammer
Eilon Krauthammer
4,768 Points

ListView doesn't display anything

Hi, I'm following the video and when I try to run the project, nothing shows up in my ListView... Here's my onResume method:

@Override
    protected void onResume() {
        super.onResume();

        ParseQuery<ParseUser> query = ParseQuery.getQuery("User");
        query.orderByAscending(ParseConstants.KEY_USERNAME);
        query.setLimit(1000);

        query.findInBackground(new FindCallback<ParseUser>() {
            @Override
            public void done(List<ParseUser> parseUsers, ParseException e) {
                if (e == null) {

                    mUsers = parseUsers;
                    String[] usernames = new String[mUsers.size()];

                    int i = 0;
                    for (ParseUser user : mUsers) {
                        usernames[i] = user.getUsername();
                        Log.v(TAG, user.getUsername());
                        i++;
                    }

                    for (int j = 0; j < usernames.length; i++) {
                        Log.v(TAG, usernames[j]);
                    }

                    ArrayAdapter<String> adapter =
                            new ArrayAdapter<String>
                                    (EditFriendsActivity.this, android.R.layout.simple_list_item_1, usernames);
                    setListAdapter(adapter);

                } else {
                    Toast.makeText
                            (EditFriendsActivity.this, e.getMessage(), Toast.LENGTH_LONG).show();
                }
            }
        });
    }

As you can see I also try to log the users but nothing happens, and I get the following warning:

Before Android 4.1, method int android.support.v7.internal.widget.ListViewCompat.lookForSelectablePosition(int, boolean) would have incorrectly overridden the package-private method in android.widget.ListView

But I don't find it particularly helpful... Why doesn't it work? Thanks!

1 Answer

Ben Jakuben
STAFF
Ben Jakuben
Treehouse Teacher
Ben Jakuben
Ben Jakuben
Treehouse Teacher

That error message is just a warning that I think you can ignore. Not totally sure, though.

Have you tried debugging your code? Add a few breakpoints and see how it executes and what data is returned, if any. Have you double-checked the name ("User") of the Parse class you are querying?

Eilon Krauthammer
Eilon Krauthammer
4,768 Points
Eilon Krauthammer
Eilon Krauthammer
4,768 Points

Apparently I just had to change back to the ParseUser.getQuery, but it shows me that it's deprecated... any reasons why/better solution?

Karan Khare
Karan Khare
3,477 Points

Hi Ben, I need your help on this, would really appreciate if you can help me through. I have organized my import. So when i am extending my app to ListActivity then my app is crashing. and so i just extend my class to Activity and commented the setListAdapter line and i tried debugging the value i am getting from parse.com is "[Ljava.lang.String;@1565baf3". So few things:- 1) is their any alternate for setListAdapter and how should solve this problem 2) is this the way we get value from parse.com or there is some issue with this. public class EditFriendActivity extends ListActivity {

public static final String TAG = EditFriendActivity.class.getName();
public List<ParseUser> mUsers;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
  requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
    setContentView(R.layout.activity_edit_friend);
}

@Override protected void onResume() { super.onResume(); setProgressBarIndeterminateVisibility(true); ParseQuery<ParseUser> query = ParseUser.getQuery(); query.orderByAscending("username"); query.setLimit(500); query.findInBackground(new FindCallback<ParseUser>() { @Override public void done(List<ParseUser> users, ParseException e) { setProgressBarIndeterminateVisibility(false); if(e==null){ mUsers = users; String usernames[] = new String[mUsers.size()]; int count=0; for(ParseUser user: mUsers){ usernames[count]=user.getUsername(); count++; } Log.v("TAG",usernames + ""); ArrayAdapter<String> adapter = new ArrayAdapter<>(EditFriendActivity.this, android.R.layout.simple_list_item_checked,usernames);

         setListAdapter(adapter);

        }else{
            Log.e(TAG,e.getMessage());
            AlertDialog.Builder builder = new AlertDialog.Builder(EditFriendActivity.this);
            builder.setMessage(e.getMessage());
            builder.setTitle("OOPS!!");
            builder.setPositiveButton(android.R.string.ok,null);
            AlertDialog dialog = builder.create();
            dialog.show();
        }
        }
    });
}

Would really appreciate your help