《疯狂安卓讲义》P189 -- 实例：使用PopupMenu创建弹出式菜单

public class MainActivity extends Activity{    PopupMenu popup = null;    @Override    protected void onCreate(Bundle savedInstanceState)    {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);    }    public void onPopupButtonClick(View button)    {        //创建PopupMenu对象        popup = new PopupMenu(this, button);        //将R.menu.popup_menu菜单资源加载到popup菜单中        popup.getMenuInflater().inflate(R.menu.popup_menu, popup.getMenu());        //为popup菜单的菜单项单击事件绑定事件监听器        popup.setOnMenuItemClickListener(                new PopupMenu.OnMenuItemClickListener()                {                    @Override                    public boolean onMenuItemClick(MenuItem item)                    {                        switch (item.getItemId())                        {                            case R.id.exit:                                //隐藏该对话框                                popup.dismiss();                                break;                            default:                                //使用Toast显示用户单击的菜单项                                Toast.makeText(MainActivity.this,                                        "您单击了【" + item.getTitle() + "】菜单项",                                        Toast.LENGTH_SHORT).show();                        }                        return true;                    }                });        popup.show();    }}<?xml version="1.0" encoding="utf-8"?><menu xmlns:android="http://schemas.android.com/apk/res/android">    <!--定义一组单选菜单项-->    <group android:checkableBehavior="single">        <!--定义四个菜单项-->        <item            android:id="@+id/find"            android:title="查找"            android:alphabeticShortcut="f"/>        <item            android:id="@+id/add"            android:title="添加"            android:alphabeticShortcut="a"/>        <item            android:id="@+id/edit"            android:title="编辑"            android:alphabeticShortcut="e"/>        <item            android:id="@+id/exit"            android:title="隐藏菜单"            android:alphabeticShortcut="w"/>    </group></menu>

<?xml version="1.0" encoding="utf-8"?><!--定义一个线性布局容器--><LinearLayout    xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    tools:context=".MainActivity"    android:orientation="vertical"    android:layout_width="match_parent"    android:layout_height="match_parent">
    <Button        android:id="@+id/button"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:onClick="onPopupButtonClick"        android:text="单击我" /></LinearLayout>