Why can't one add/remove items from an ArrayAdapter?

Question

I am using an ArrayAdapter to populate the items to list in a android.widget.Spinner. That works all fine.

But now I wa

Answer 1

In your adapter Class - Delete an Item

remove(position);
notifyDataSetChanged();

Add an Item -

adapter.add (newItem);
adapter.notifyDataSetChanged ();

Answer 2

You probably initialized the adapter with a plain Java array (e.g., String[]). Try using something that implements the java.util.List interface (e.g., ArrayList<String>).

Answer 3

I know it's late but just a quick explanation: it's because method Arrays.asList(T... array) returns custom inner class named ArrayList that is read-only. As already said, you need to provide full impl. e.g. java.util.ArrayList.

Answer 4

You can try like this:

new ArrayList<>(Arrays.asList(recentlyClient))

Example code how to implement:

String[] recentlyClient;

ArrayAdapter<String> recenAdapter = new ArrayAdapter<String>(MainActivity.this,android.R.layout.simple_list_item_1,new ArrayList<>(Arrays.asList(recentlyClient)));

Answer 5

Probably, you are using List in your ArrayAdapter class instead of ArrayList.

Try converting your array or list to ArrayList -

new ArrayList<ClassType>(Arrays.asList(array));

Answer 6

I was having the same problem, my data was saved in resource String Array, so I was creating ArraAdapter with createFromResource.
The following code for creating ArrayAdapter from resource String Array solved the problem:

Resources res = getResources();
String[] cities = res.getStringArray(R.array.cities_array);
ArrayAdapter<CharSequence> adapter = new ArrayAdapter(
     this,
     android.R.layout.simple_spinner_item,
     new ArrayList(Arrays.asList(cities)));