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>