【android控件学习笔记】使用Spinner实现下拉列表

public class MainActivity extends Activity {

private TextView myTextView;
private Spinner mySpinner;
private SimpleAdapter adapter;
private List<Map<String, Object>> dataList;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// 第一步：添加一个下拉列表项的list，这里添加的项就是下拉列表的菜单项
dataList = new ArrayList<Map<String, Object>>();
getData();
myTextView = (TextView) findViewById(R.id.textView);
mySpinner = (Spinner) findViewById(R.id.spinner);
// 第二步：为下拉列表定义一个适配器，这里就用到里前面定义的list。
adapter=new SimpleAdapter(this, dataList, R.layout.item, new String[]{"image","text"}, new int[]{R.id.image,R.id.text});

// 第三步：为适配器设置下拉列表下拉时的菜单样式。
adapter.setDropDownViewResource(R.layout.item);
// 第四步：将适配器添加到下拉列表上
mySpinner.setAdapter(adapter);
// 第五步：为下拉列表设置各种事件的响应，这个事响应菜单被选中

mySpinner
.setOnItemSelectedListener(new Spinner.OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> arg0, View arg1,
int arg2, long arg3) {
// TODO Auto-generated method stub
/* 将所选mySpinner 的值带入myTextView 中 */
myTextView.setText("您选择的是：" + adapter.getItem(arg2));
}

public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
myTextView.setText("NONE");
}
});

}

private void getData() {
// TODO Auto-generated method stub
Map<String, Object> map = new HashMap<String, Object>();
map.put("image", R.drawable.ic_launcher);
map.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(map);
dataList.add(map2);
dataList.add(map3);
dataList.add(map4);
}

}