Spinner doesn't show array and texts

2
votes

I'm a very beginner. The spinner doesn't work. It didn't use to show arrow when I was just playing with it in design mode, it's not showing text after I implemented it with some code somehow.

        android:id="@+id/spinner"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        />```

```    Spinner spinner;
    ArrayList spinnerArrayList;
    ArrayAdapter spinnerAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        spinner = findViewById(R.id.spinner);
        spinnerArrayList = new ArrayList();
        spinnerAdapter = new ArrayAdapter(this,android.R.layout.simple_spinner_item,spinnerArrayList);
        spinnerAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinner.setAdapter(spinnerAdapter);

        spinnerArrayList.add("Guitar");
        spinnerArrayList.add("Drums");
        spinnerArrayList.add("Keyboard");

    }```

I'm sure these are the standards and basic things, but somehow I'm screwed up
2
javaandroidspinner
You're updating the ArrayList after assigning it to the adapter. By default, Spinner doesn't keep a reference to the original list added to the adapter so to retain the changes you should use what has been provided here in this link. - Lalit Fauzdar

2 Answers

2
votes

What you are doing is you are changing your ArrayList after setting up the adapter. So adapter doesn't know that the data is changed.

You can solve this in 2 ways :

  1. Add elements in the ArrayList before setting up the adapter

  2. Use notifyDataSetChanged() at the end of the code or whenever you change the ArrayList

Like this : spinnerAdapter.notifyDataSetChanged()

1
votes

There is no need to create ArrayAdapter to populate your spinner if the list you want to insert is static. I recommend using a way easier and direct method to avoid this hassle.

In strings.xml:

<string-array name="list_spinner">
<item>Guitar</item>
<item>Drums</item>
<item>Keyboard</item>
</string-array>

In the layout that contains your spinner:

<Spinner 
        android:id="@+id/spinner"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:entries="@array/list_spinner"
    />

And You're Done!

EXTRA: If you want to make your spinner responsive to item selection in your spinner, add this code to the corresponding .java file of the layout containing the spinner in the onCreate() method:

final Spinner spin=findViewById(R.id.spinner);
spin.setOnItemSelectedListener(new OnItemSelectedListener() {

            @Override
            public void onItemSelected(AdapterView<?> arg0, View arg1,
                    int arg2, long arg3) {
                // TODO Auto-generated method stub
                String item_name=spin.getSelectedItem().toString();

                Log.e("Selected item : ",item_name);
}

            @Override
            public void onNothingSelected(AdapterView<?> arg0) {
                // TODO Auto-generated method stub

            }
    });