写Spinner的步骤：
1、设置数据源。用List集合来写 2、新建ArrayAdapter（数组适配器） 3、设置一个下拉列表样式 4、Spinner加载适配器 5.设置监听器OnItemSelectedListener()
两种Spinner下拉列表的用法第一种：
主函数：
.OnItemSelectedListener{private TextView mTextView;private Spinner mSpinner;private List<String>list;private ArrayAdapter<String>adapter;(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);mTextView= (TextView) findViewById(R.id.textview);mSpinner= (Spinner) findViewById(R.id.spinner);//1、设置数据源list=new ArrayList<>();list.add(“北京”);list.add(“上海”);list.add(“青岛”);list.add(“深圳”);list.add(“成都”);//新建ArrayAdapter（数组适配器）adapter=new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,list);//给adapter设置一个下拉列表样式adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);//Spinner去加载适配器mSpinner.setAdapter(adapter);//设置监听器mSpinner.setOnItemSelectedListener(this);}(AdapterView<?> parent, View view, int position, long id) {//获取当前城市的名字//String cityName=list.get(position);String city=adapter.getItem(position);mTextView.setText(“你选择的城市”+city);}(AdapterView<?> parent) {}}
布局文件：
<LinearLayout xmlns:android=”http://schemas.android.com/apk/res/android”xmlns:tools=”http://schemas.android.com/tools”android:layout_width=”match_parent”android:layout_height=”match_parent”android:orientation=”vertical”tools:context=”.MainActivity”><TextViewandroid:id=”@+id/textview”android:layout_width=”match_parent”android:layout_height=”wrap_content”android:textSize=”25sp”android:textColor=”#ff00ff” /><Spinnerandroid:id=”@+id/spinner”android:layout_width=”match_parent”android:layout_height=”wrap_content”></Spinner></LinearLayout>第二种：
主函数：
{private TextView mTextView;private Spinner mSpinner;private SimpleAdapter adapter;private List<Map<String, Object>> datalist;(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);mTextView = (TextView) findViewById(R.id.textview_main);mSpinner = (Spinner) findViewById(R.id.spinner);//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<>();//第二步：为下拉列表定义一个适配器,这里就用到前面的listadapter = new SimpleAdapter(this, getData(), R.layout.item, new String[]{“image”, “text”}, new int[]{R.id.image, R.id.textview});//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);//将适配器添加到下拉列表上mSpinner.setAdapter(adapter);//第五步：为下拉列表设置各种事件的相应，，这个事件响应菜单被选中mSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {(AdapterView<?> parent, View view, int position, long id) {mTextView.setText(“你选择的是” + adapter.getItem(position));}(AdapterView<?> parent) {mTextView.setText(“NONE”);}});}private List<Map<String, Object>> getData() {Map<String, Object> map = new HashMap<>();map.put(“image”, R.mipmap.ic_launcher);map.put(“text”, “北京”);Map<String, Object> map2 = new HashMap<>();map2.put(“image”, R.mipmap.ic_launcher);map2.put(“text”, “成都”);Map<String, Object> map3 = new HashMap<>();map3.put(“image”, R.mipmap.ic_launcher);map3.put(“text”, “深圳”);Map<String, Object> map4 = new HashMap<>();map4.put(“image”, R.mipmap.ic_launcher);map4.put(“text”, “青岛”);Map<String, Object> map5 = new HashMap<>();map5.put(“image”, R.mipmap.ic_launcher);map5.put(“text”, “济南”);Map<String, Object> map6 = new HashMap<>();map6.put(“image”, R.mipmap.ic_launcher);map6.put(“text”, “香港”);datalist.add(map);datalist.add(map2);datalist.add(map3);datalist.add(map4);datalist.add(map5);datalist.add(map6);return datalist;}}有勇气并不表示恐惧不存在，而是敢面对恐惧、克服恐惧
