constructor of class ArrayAdapter

Question

i have this into fragment in onCreateView():

ListView listView = (ListView) rootView.findViewById(R.id.listview);
        ListAdapter listAdapter = new MyListAdapter();
        listView.setAdapter(listAdapter);

MyListAdapter:

public class MyListAdapter extends ArrayAdapter {

    /*public MyListAdapter(Context context, int textViewResourceId) {
        super(context, textViewResourceId);
    }*/


   /* public MyListAdapter(Context context, int resource, List<ClipData.Item> items) {
        super(context, resource, items);
    }*/




    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View row = convertView;

        Spinner spinner = (Spinner) convertView.findViewById(R.id.simpleSpinner);
        ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
                getContext(),
                R.array.country_arrays,
                android.R.layout.simple_spinner_item);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinner.setAdapter(adapter);

        return row;
    }

    }

ARRAY ADAPTER:

public class MyListAdapter extends ArrayAdapter implements AdapterView.OnItemSelectedListener{
    Spinner spinner;
    ListView listView;

    /*public MyListAdapter(Context context, int textViewResourceId) {
        super(context, textViewResourceId);
    }*/

    public MyListAdapter(Context context) {
        super(context, R.layout.single_listview_item);
    }




    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View row = convertView;

         spinner = (Spinner) convertView.findViewById(R.id.simpleSpinner);
        ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
                getContext(),
                R.array.country_arrays,
                android.R.layout.simple_spinner_item);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinner.setAdapter(adapter);

        return row;
    }
    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
        //Spinner spinner = null;
        System.out.println("ciao");
        listView.setSelection(position);
        String selState = (String) listView.getSelectedItem();
        Toast.makeText(
                getContext(),
                "Clicked on Planet: " + selState + "", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onNothingSelected(AdapterView<?> parent) {

    }
    }

Now my question is: what i must write into constructor of class MyListAdapter?

Thanks!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Post the code for MyListAdapter (I assume that's your class extending ArrayAdapter). — Spidey, Jul 24 '16 at 10:51

score 0 · Answer 1 · edited May 23 '17 at 12:14

0

There are 6 constructors in ArrayAdapter class. You have to implement any one of them according to your requirement.

For more details you may follow this link

edited May 23 '17 at 12:14

Community

1
1

answered Jul 24 '16 at 10:54

Md Sufi Khan

1,751
1
14
19

and in my case how can i must write constructor? – Lo_Zio Jul 24 '16 at 11:00

Maciej Sikora · Accepted Answer · 2016-07-24T11:15:41.627

0

Every extending class must have minimum one constructor matching parent class. So Your class must have constructor with one line and calling super on it, no own code is required.

public MyListAdapter(Context context, int resource ) {

    super(context, resource);
    //your code 

}

But when You create your Adapter you are using constructor so You can create any constructor, important is to use super in it.

In constructor You can for example implement code to set data to list from database.

You can for example create constructor like that:

public MyListAdapter(Context context) {

    super(context, R.layout.row_view);

    //your code 


}

and

    ListView listView = (ListView) rootView.findViewById(R.id.listview);
    ListAdapter listAdapter = new MyListAdapter(getContext());
    listView.setAdapter(listAdapter);

edited Jul 24 '16 at 11:15

answered Jul 24 '16 at 10:54

Maciej Sikora

19,374
4
49
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and in my case how can i must write constructor? – Lo_Zio Jul 24 '16 at 11:02
and in fragment, which arguments i pass to MyListAdapter? – Lo_Zio Jul 24 '16 at 11:19
for sure You must pass context like i writed in example: getContext() will get context from fragment. – Maciej Sikora Jul 24 '16 at 11:21
@Lo_Zio you must fill your adapter so You can pass elements by constructor on fill in inside Your adapter, in beggining You have no elements there so list will be empty. – Maciej Sikora Jul 24 '16 at 11:22
and onItemSelected must be into arrayAdapter? – Lo_Zio Jul 24 '16 at 11:41
onItemSelected is i suppose method of list not adapter. Adapter is for data, for managing view you have listView – Maciej Sikora Jul 24 '16 at 11:45
i posted code about onItemSelected...can you help me? now with this code it doesn't work... – Lo_Zio Jul 24 '16 at 11:52
1

@Lo_Zio create new question – Maciej Sikora Jul 24 '16 at 12:13

constructor of class ArrayAdapter

2 Answers2