I can't set onItemSelectedListener in spinner array by 'for' Loop

Question

I have nine spinners with same function, input value to int array.

So, I wrote code with 'for' Loop. I thought that's effective. But it didn't work.

When I execute this and check spinner, there's no change of int array.

How can I input value to int array with 'for' Loop?

//global
int num;

ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
        android.R.layout.simple_spinner_item, items);
spinner[] spinner;
spinner = new Spinner[9];
int[] values;
values = new int[9];

for(int i = 0; i < 9; i++){
    spinner[i] = new Spinner(this);
    spinner[i] = (Spinner) findViewById(spinnerId[i]);
    spinner[i].setAdapter(adapter);
    values[i] = 0;
}       

//OnItemSelectedListener
for(int i = 0; i < 9; i++){
    num++;
    spinner[i].setOnItemSelectedListener(new
        AdapterView.OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> parent,
                View view, int position, long id) {
            values[num] = position;
        }

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

        }
    });
}

It's because when the onItemSelected method is called, num is equal to 9. Try changing `values[num] = position;` To: `final int finalNum = num; values[finalNum] = position;` — RobVoisey, Oct 16 '15 at 11:02
Not certain its valid off the top of my head without testing it, if it works, let me know and I'll turn it into an answer. If not, you'll need to iterate over your Spinner array to find the one that has been pressed. — RobVoisey, Oct 16 '15 at 11:03
@SilambarasanPoonguti Yes, I thought It's effective. but I was wrong :-( — Johannes Lee, Oct 16 '15 at 11:11
@SamirBhatt I found someone wrote how to do that. I think It's what you try to tell me :-) http://stackoverflow.com/questions/9262871/android-two-spinner-onitemselected — Johannes Lee, Oct 16 '15 at 11:12

liloargana · Answer 1 · 2015-10-16T11:43:12.540

The reason this is not working

values[num] = position;

The num value is 9 always when the event listener triggers.

You could create an inner class implementing the listener interface, with an index varible assigned on constructor, like this:

    private class IndexedItemSelectedListener implements AdapterView.OnItemSelectedListener {

    private final int index;

    public IndexedItemSelectedListener(int index) {
        this.index = index;
    }

    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
        values[index] = position;
    }

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

    }
}

And use it like this:

        //OnItemSelectedListener
    for (int i = 0; i < spinner.length; i++) {
        spinner[i].setOnItemSelectedListener(new IndexedItemSelectedListener(i));
    }

score 1 · Accepted Answer · edited Oct 29 '21 at 17:23

Try this....

1. activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="match_parent"
   android:layout_height="match_parent">

   <LinearLayout
       android:id="@+id/spinner_container"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:layout_centerInParent="true"
       android:orientation="vertical"/>

   <TextView
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:text="Dynamic Spinner"
       android:id="@+id/textView3"
       android:textColor="#000000"
       android:textSize="18sp"
       android:layout_alignParentTop="true"
       android:layout_centerHorizontal="true"
       android:layout_marginTop="64dp" />

</RelativeLayout>

2.MainActivity.java

public class MainActivity extends AppCompatActivity {

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

    GenerateView();
}


private void GenerateView() {

    mContainer = (LinearLayout)findViewById(R.id.spinner_container);
    LinearLayout.LayoutParams mRowLayoutParams = new LinearLayout.LayoutParams(TableRow.LayoutParams.MATCH_PARENT,
            TableRow.LayoutParams.WRAP_CONTENT);
    mRowLayoutParams.gravity = Gravity.CENTER_HORIZONTAL;
    mRowLayoutParams.setMargins(8, 8, 8, 8);

    String[] ITEMS = {"Item 1", "Item 2", "Item 3", "Item 4", "Item 5", "Item 6"};
    ArrayAdapter<String> adapter0 = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, ITEMS);
    adapter0.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

    for (int i = 0; i < 9; i++) {
        Spinner spinner = new Spinner(this);
        spinner.setId(i);
        spinner.setAdapter(adapter0);
        spinner.setOnItemSelectedListener(mOnItemSelectedListener);
        spinner.setLayoutParams(mRowLayoutParams);
        mContainer.addView(spinner);
    }

}

private AdapterView.OnItemSelectedListener mOnItemSelectedListener = new AdapterView.OnItemSelectedListener() {
    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {

        Spinner spinner = (Spinner) parent;

        switch (spinner.getId()) {
            case 0:
                shpwToast(spinner.getSelectedItem().toString());
                break;
            case 1:
                shpwToast(spinner.getSelectedItem().toString());
                break;
            case 3:
                shpwToast(spinner.getSelectedItem().toString());
                break;
            case 4:
                shpwToast(spinner.getSelectedItem().toString());
                break;
            case 5:
                shpwToast(spinner.getSelectedItem().toString());
                break;
            case 6:
                shpwToast(spinner.getSelectedItem().toString());
                break;
            case 7:
                shpwToast(spinner.getSelectedItem().toString());
                break;
            case 8:
                shpwToast(spinner.getSelectedItem().toString());
                break;
            case 9:
                shpwToast(spinner.getSelectedItem().toString());
                break;
        }
    }

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

    }
  };

  private void shpwToast(String content) {
    Toast.makeText(MainActivity.this, "Item Selected : " + content, Toast.LENGTH_SHORT).show();
   }

  }

3. Result

I can't set onItemSelectedListener in spinner array by 'for' Loop

2 Answers2