老师能帮忙看看我自己学着写的这个SimpleAdapter的例子哪里出问题了么，将这个程序部署到模拟器后直接闪退了，谢谢

public class MainActivity extends Activity implements OnItemSelectedListener{

private TextView textView;
private Spinner spinner; 
private SimpleAdapter sim_adapter;
private List<Map<String, Object>>dataList;

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

        textView = (TextView) findViewById(R.id.textView);
        spinner = (Spinner) findViewById(R.id.spinner);
        
        textView.setText("您选择的是：北京");

        dataList = new ArrayList<Map<String,Object>>();

        sim_adapter = new SimpleAdapter(this, getData(), R.layout.item, new String[]{"image", "text"}, new int[]{R.id.image, R.id.text});
        
        sim_adapter.setDropDownViewResource(R.layout.item);
        
        spinner.setAdapter(sim_adapter);
        
        spinner.setOnItemSelectedListener(this);
    }

private List<Map<String, Object>> getData() {
Map<String, Object>map1 = new HashMap<String, Object>();
map1.put("image", R.drawable.ic_launcher);
map1.put("text", "北京");
Map<String, Object>map2 = new HashMap<String, Object>();
map2.put("image", R.drawable.ic_launcher);
map2.put("text", "上海");
Map<String, Object>map3 = new HashMap<String, Object>();
map3.put("image", R.drawable.ic_launcher);
map3.put("text", "广州");
Map<String, Object>map4 = new HashMap<String, Object>();
map4.put("image", R.drawable.ic_launcher);
map4.put("text", "深圳");

dataList.add(map1);
dataList.add(map2);
dataList.add(map3);
dataList.add(map4);
       
return dataList;
}

@Override
public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
String cityName = (String) sim_adapter.getItem(arg2);
textView.setText("您选择的是："+cityName);

}

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

}

}