title: how to add item to Spinner's ArrayAdapter?
body: <p>i had a EditText , a button and a spinner . When click the button , the spinner will add a new item with name you entered in the EditText. But here is the question,  my adapter.add() method seems doesn't work...here is my code:</p>
  
  <pre><code>public class Spr extends Activity {
  Button bt1;
  EditText et;
  ArrayAdapter&lt;CharSequence&gt; adapter;
  Spinner spinner;
  @Override
  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.main);
  
      bt1 = (Button)this.findViewById(R.id.bt1);
      et = (EditText)this.findViewById(R.id.et);  
      spinner = (Spinner)this.findViewById(R.id.spr);
  
      adapter = ArrayAdapter.createFromResource(
              this, R.array.planets_array, android.R.layout.simple_spinner_item);
  
      adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
  
      spinner.setAdapter(adapter);
  
      bt1.setOnClickListener(new View.OnClickListener() {
  
          @Override
          public void onClick(View v) {
              String temp = et.getText().toString();
  
              adapter.add(temp);
              adapter.notifyDataSetChanged();
              spinner.setAdapter(adapter);
  
          }
      });
  
  
      spinner.setOnItemSelectedListener(new Spinner.OnItemSelectedListener(){
  
          @Override
          public void onItemSelected(AdapterView&lt;?&gt; parent, View view,
                  int pos, long id) {
  
              Toast.makeText(parent.getContext(), "The planet is " +
                        parent.getItemAtPosition(pos).toString(), Toast.LENGTH_LONG).show();
  
          }
  
          @Override
          public void onNothingSelected(AdapterView&lt;?&gt; arg0) {
  
          }});
  }
  </code></pre>
  
  <p>}</p>
  
  <p>thanks! ...still waitting</p>