Android实现下拉菜单效果 Android实现下拉菜单Spinner效果

<?xml version="1.0" encoding="utf-8"?> 
<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="com.rj141.sb.kongjian.MainActivity"> 
 
  <LinearLayout 
    android:orientation="horizontal" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content"> 
    <TextView 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:textSize="18dp" 
      android:text="请选择您最喜欢的水果：" /> 
 
    <Spinner 
      android:layout_width="match_parent" 
      android:layout_height="wrap_content" 
      android:id="@+id/spinner" /> 
  </LinearLayout> 
 
 
  <TextView 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:textSize="18dp" 
    android:id="@+id/tv" /> 
 
</LinearLayout> 

public class MainActivity extends AppCompatActivity { 
 
  private Spinner s; 
  String[] data=new String[]{"苹果","雪梨","西瓜","葡萄","橙子","草莓"}; 
  private TextView tv; 
 
  @Override 
  protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
 
    tv= (TextView) this.findViewById(R.id.tv); 
    s= (Spinner) this.findViewById(R.id.spinner); 
    s.setAdapter(new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,data)); 
    s.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() { 
      @Override 
      public void onItemSelected(AdapterView<?> parent, View view, int position, long id) { 
        String str=data[position]; 
        tv.setText("最喜欢的水果是："+str); 
      } 
      @Override 
      public void onNothingSelected(AdapterView<?> parent) { 
      } 
    }); 
  } 
} 
s.setAdapter(new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,data))；android.R.layout.simple_list_item_1是指安卓自带的下拉列表格式，data是数据源；
s.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener()){..}；是下拉列表的监听