android Spinner setAdapter ArrayAdapter

1.xml:

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

2.code:

        List<String> _spinnerList;
        ArrayAdapter _spinnerAdapter;

        _spinnerList = new ArrayList<String>();
        _spinnerAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item, _spinnerList);
        

        _spinnerList.add("1");
        _spinnerList.add("2");
        _spinnerList.add("3");
        
        Spinner spinner = (Spinner)this.findViewById(R.id.spinner);
        spinner.setAdapter(_spinnerAdapter);

3.event:

            _spinner.setOnItemSelectedListener(new OnItemSelectedListener(){

                @Override
                public void onItemSelected(AdapterView<?> parent, View view,
                        int position, long id) {
                    // get content:
                    // String content = (String) parent.getItemAtPosition(position);
                    // or:
                    // String item = _spinnerList.get(position);
                }

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

4.last:

thanks!