CODEWITHSUNDEEP
androidlistadapter
Lambros
Lambros

Reputation: 151

Android ListView does not show list items

I wanna add items to my list but it only shows the first one:

public class MainActivity extends Activity {

    Server server;
    TextView infoip, msg;
    TextView usersTitle;
    String[] array = {"a"};
    ArrayList<String> lst;
    ArrayAdapter<String> adapter;
    ListView userList;

    @Override
    public void onCreate(Bundle savedInstanceState) {        
        lst = new ArrayList<String>(Arrays.asList(array));
        adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, lst);
        userList = (ListView) findViewById(R.id.userList);
        userList.setAdapter(adapter);

From this other class method, everytime it is called I want the text to go below the first one. The method certainly runs but it does not put the text below the previous one. It just shows "a"! Anyone knows why?

activity.runOnUiThread(new Runnable() {
                    @Override
                    public void run() {


                        activity.lst.add(message);
                        activity.adapter.notifyDataSetChanged();                           

                    }
                });

I have also tried:

adapter.insert(String, int);

lst.add(int, String);

And even added in the onCreate method this:

lst.add(1, "2");
adapter.notifyDataSetChanged();

And still doesnt add the "2"!!

Upvotes: 0

Views: 958

Answers (5)

Nishat Jahan
Nishat Jahan

Reputation: 399

Here is the solution to your Problem.I have created an Activity class and Tests java class.

public class MainActivity extends Activity {
String[] array = {"a"};
public static ArrayList<String> lst;
ArrayAdapter<String> adapter;
ListView userList;
Tests tests = new Tests();

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    userList = (ListView) findViewById(R.id.userList);
    lst = new ArrayList<String>(Arrays.asList(array));
    adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, lst);

    userList.setAdapter(adapter);
    tests.callThread();
}

}

Here is the Tests.java Class public class Tests {

int i = 0;
String message = "";
Thread runOnUiThread;

public void callThread()

{


    new Thread(new Runnable() {

        @Override
        public void run() {
            try {
                while (i < 10) {
                    i = i + 1;
                    message = String.valueOf(i);
                    //Create a server socket object and bind it to a port
                    MainActivity.lst.add(message);
                }


                }catch(Exception e){
                    e.printStackTrace();
                }
        }
    }).start();
}

}

Just call your service inside this thread where I have incremented variable i and by this way you can populate the list in right order.

Upvotes: 1

user1587700
user1587700

Reputation:

I'm suspicious about the runOnUiThread. Can you provide more information why did you use this function? Also i highly recommend using RecyclerView

Also you can refer to this post for adding items to RecyclerView

Upvotes: 0

Harv
Harv

Reputation: 476

Try to make "lst" and "adapter" both static.

Upvotes: 0

gautam90
gautam90

Reputation: 58

Can you tell whether the other class is Activity or Fragment ? And while adding the data into Arraylist, you don't need the Thread to be run in order to insert new data to Arraylist

Upvotes: 0

Nishat Jahan
Nishat Jahan

Reputation: 399

If you are adding items to Arraylist from another class ,you have to declare your Arraylist Static.So that it can hold items in memory.

Replace ArrayList lst with public static ArrayList

Upvotes: 1

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