Android ActionBar制作时钟实例解析

package com.example.days19actionbar07custom;
 
import com.example.days19actionbar07custom.R;
 
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MenuItem.OnActionExpandListener;
import android.view.View;
import android.widget.AnalogClock;
import android.widget.SearchView;
import android.widget.SearchView.OnQueryTextListener;
import android.widget.TextView;
 
public class MainActivity extends Activity {
 
 private TextView txtResult = null;
 
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
 
  txtResult = (TextView) findViewById(R.id.txtResult);
 }
 
 @Override
 public boolean onCreateOptionsMenu(Menu menu) {
  getMenuInflater().inflate(R.menu.main, menu);
 
   
  /**************searchView*****************/
  // 通过id找到相对应的MenuItem（SearchView）
  MenuItem searchItem = menu.findItem(R.id.action_search);
 
  SearchView view = (SearchView) searchItem.getActionView();
 
  // 给SearchView设置文字改变的监听
  view.setOnQueryTextListener(new OnQueryTextListener() {
 
   @Override
   public boolean onQueryTextSubmit(String query) {
    return false;
   }
 
   @Override
   public boolean onQueryTextChange(String newText) {
    txtResult.setText("您正在搜索" + newText);
    return false;
   }
  });
   
  /**************自定义条目*****************/
   
  // 通过id找到自定义布局MenuItem
  MenuItem customItem = menu.findItem(R.id.action_custom_layout);
   
  // 通过menuItem的getActionView（）方法得到一个View对象
  View v = customItem.getActionView();
   
  // 可以通过v的findViewById()方法找到自定义布局中的相对应的控件
  AnalogClock acClock = (AnalogClock) v.findViewById(R.id.acClock);
   
  // 给customItem菜单条目设置展开折叠监听
  customItem.setOnActionExpandListener(new OnActionExpandListener() {
    
   /**
    * 菜单条目被展开
    * 返回为true代表该条目菜单可以被展开
    * @Override
    */
   public boolean onMenuItemActionExpand(MenuItem item) {
    txtResult.setText("时钟被展开");
    return true;
   }
    
   /**
    * 菜单条目被折叠
    * 返回为true代表该条目菜单可以被折叠
    * @Override
    */
   public boolean onMenuItemActionCollapse(MenuItem item) {
    txtResult.setText("时钟被折叠");
    return true;
   }
  });
  return true;
 }
 
}

<menu xmlns:android="http://schemas.android.com/apk/res/android" >
 
 <item
  android:id="@+id/action_search"
  android:orderInCategory="100"
  android:actionViewClass="android.widget.SearchView"
  android:showAsAction="always"
  android:title="@string/it_search"/>
 
 <item
  android:id="@+id/action_custom_layout"
  android:actionLayout="@layout/my_layout"
  android:orderInCategory="100"
  android:icon="@drawable/ic_launcher"
  android:showAsAction="always|collapseActionView"
  android:title="layout"/>
 
</menu>

<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
 android:paddingLeft="@dimen/activity_horizontal_margin"
 android:paddingRight="@dimen/activity_horizontal_margin"
 android:paddingTop="@dimen/activity_vertical_margin"
 tools:context=".MainActivity" >
 
 <TextView
  android:id="@+id/txtResult"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:text="@string/hello_world" />
 
</RelativeLayout>

<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
 android:paddingLeft="@dimen/activity_horizontal_margin"
 android:paddingRight="@dimen/activity_horizontal_margin"
 android:paddingTop="@dimen/activity_vertical_margin"
 tools:context=".MainActivity" >
 
 <AnalogClock
  android:id="@+id/acClock"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:text="@string/hello_world" />
 
</RelativeLayout>