Android ActionBar 一步一步分析 （转）

原文摘自：http://blog.csdn.net/android2me/article/details/8874846

 

1.Action Bar 介绍

我们能在应用中看见的actionbar一般就是下图的样子，比如快图应用

1.App icon 应用的图标，左侧带应用相当于back返回键

2.ViewControl

3.Action button 相当于普通的Button可以监听点击事件

 

4.Action overflow 三个点，相当于手机上的menu键，可以显示隐藏的action button

下面是一个简单的关于Action Bar的例子：

 

package com.example.demo_actionbarbasic;
import com.example.demo_actionbarbasic.R;
import android.app.ActionBar;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;

public class MainActivity extends Activity {
    private MenuItem menuItem = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // 通过hilde()和show()方法可以控制actionbar的隐藏和显示
        // ActionBar actionBar = getActionBar();
        // actionBar.hide();
        // actionBar.show();
    }

    // 我们可以看到，actonbar的用法跟选项菜单是一样的
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        case R.id.action_refresh:
            Toast.makeText(this, "Menu Item refresh selected",
                    Toast.LENGTH_SHORT).show();
            break;
        case R.id.action_about:
            Toast.makeText(this, "Menu Item about selected", Toast.LENGTH_SHORT)
                    .show();
            break;
        case R.id.action_edit:
            Toast.makeText(this, "Menu Item edit selected", Toast.LENGTH_SHORT)
                    .show();
            break;
        case R.id.action_search:
            Toast.makeText(this, "Menu Item search selected",
                    Toast.LENGTH_SHORT).show();
            break;
        case R.id.action_help:
            Toast.makeText(this, "Menu Item  settings selected",
                    Toast.LENGTH_SHORT).show();
            break;
        default:
            break;
        }
        return super.onOptionsItemSelected(item);
    }
}

 

<menu xmlns:android="http://schemas.android.com/apk/res/android" >
    <item
        android:id="@+id/menu_settings"
        android:orderInCategory="100"
        android:showAsAction="never"
        android:title="settings"/>
    <item
        android:id="@+id/action_refresh"
        android:icon="@drawable/navigation_refresh"
        android:orderInCategory="101"
        android:showAsAction="ifRoom|withText"
        android:title="refresh"/>
    <item
        android:id="@+id/action_about"
        android:icon="@drawable/action_about"
        android:orderInCategory="101"
        android:showAsAction="ifRoom"
        android:title="about"/>
    <item
        android:id="@+id/action_search"
        android:icon="@drawable/action_search"
        android:orderInCategory="103"
        android:showAsAction="ifRoom"/>
    <item
        android:id="@+id/action_edit"
        android:icon="@android:drawable/ic_menu_edit"
        android:orderInCategory="105"
        android:showAsAction="ifRoom"
        android:title="edit"/>
    <item
        android:id="@+id/action_help"
        android:showAsAction="always"
        android:title="help"/>
    <item
        android:id="@+id/action_email"
        android:icon="@android:drawable/ic_dialog_email"
        android:orderInCategory="106"
        android:showAsAction="ifRoom"
        android:title="email"/>
</menu>

 

onCreateOptionsMenu()方法用来加载menu文件夹中定义的xml文件，用来显示action bar。onOptionsItemSelected()方法用来加入点击事件。

效果图：

         

 

左图的效果我们看到只能显示两个action button，由于屏幕的空间有限，其他的action button会被隐藏。横屏的时候我们可以显示4个，还有3个被隐藏起来了。当我们按手机上的更多键时可以显示出来关于action button的文字信息，一定要在item标签中加入title属性。

 

android:showAsAction="ifRoom"ifRomm表示有空间的时候显示。

android:showAsAction="always"表示总是显示

android:showAsAction="ifRoom|withText"有空间的时候同时显示title标题

其他属性可以自己试试。

 

2.显示3个点的更多action button

从上面的代码我们知道，即使我们横屏也显示不出全部action button。我们可以加入3个点的action button来用下拉显示的方式，显示跟多的action button。在网上的信息得知，只要你的手机有menu键actionbar就不会显示3个点的更多或者说3个点的menu按钮。从上面的代码我们知 道，即使我们横屏也显示不出全部action button。我们可以加入3个点的action button来用下拉显示的方式，显示跟多的action button。在网上的信息得知，只要你的手机有menu键actionbar就不会显示3个点的更多或者说3个点的menu按钮。

 

private void getOverflowMenu() {

     try {
        ViewConfiguration config = ViewConfiguration.get(this);
        Field menuKeyField = ViewConfiguration.class.getDeclaredField("sHasPermanentMenuKey");
        if(menuKeyField != null) {
            menuKeyField.setAccessible(true);
            menuKeyField.setBoolean(config, false);
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

在onCreat（）方法中调用这个方法可以显示3个点的menu按钮。下图是按下3个点的action button的效果

 

代码：Demo_ActionBar3dot

动态action button 

用到了MenuItem 类的，setActionView()和collapseActionView()这两个方法。 这个例子的效果是当我们点击refresh action button的时候会显示进度条。

 

package com.example.demo_actionbar;

import android.app.ActionBar;
import android.app.Activity;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.TextView.OnEditorActionListener;
import android.widget.Toast;

public class MainActivity extends Activity {

    private MenuItem menuItem = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // TODO Auto-generated method stub
        switch (item.getItemId()) {
        case R.id.action_refresh:
            menuItem = item;
            menuItem.setActionView(R.layout.progressbar);
            TestTask task = new TestTask();
            task.execute("test");
            break;
        case R.id.action_about:
            Toast.makeText(this, "Menu Item about selected", Toast.LENGTH_SHORT)
                    .show();
            break;
        default:
            break;
        }
        return super.onOptionsItemSelected(item);
    }

    private class TestTask extends AsyncTask<String, Void, String> {

        @Override
        protected String doInBackground(String... params) {
            // Simulate something long running
            try {
                Thread.sleep(2000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            return null;
        }

        @Override
        protected void onPostExecute(String result) {
            menuItem.collapseActionView(); // 这个方法需要 API 14 以上
            menuItem.setActionView(null);
        }
    };
}

 

Actionbar之spinner实现drop-down Navigation

1.首先需要一个SpinnerAdapter设置下拉item的内容和显示的layout

2.实现ActionBar.OnNavigationListener这个接口，接口中有点击item的事件
3.设置navigation mode例如
ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_LIST);
4.用 setListNavigationCallbacks()方法来实现下拉选项，例如
actionBar.setListNavigationCallbacks(mSpinnerAdapter, mNavigationCallback);

 

效果图：

代码：

 

package in.wptrafficanalyzer.actionbardropdownnavigation;

import android.app.ActionBar;
import android.app.ActionBar.OnNavigationListener;
import android.app.Activity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.Toast;

public class MainActivity extends Activity {

    /** An array of strings to populate dropdown list */
    String[] actions = new String[] { "Bookmark", "Subscribe", "Share" };

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        /** Create an array adapter to populate dropdownlist */
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(
                getBaseContext(),
                android.R.layout.simple_spinner_dropdown_item, actions);

        /** Enabling dropdown list navigation for the action bar */
        getActionBar().setNavigationMode(ActionBar.NAVIGATION_MODE_LIST);

        /** Defining Navigation listener */
        ActionBar.OnNavigationListener navigationListener = new OnNavigationListener() {

            @Override
            public boolean onNavigationItemSelected(int itemPosition,
                    long itemId) {
                Toast.makeText(getBaseContext(),
                        "You selected : " + actions[itemPosition],
                        Toast.LENGTH_SHORT).show();
                return false;
            }
        };

        /**
         * Setting dropdown items and item navigation listener for the actionbar
         */
        getActionBar().setListNavigationCallbacks(adapter, navigationListener);
    }
}

代码下载：Demo_ActionBarDropdownNavigation

 

Action Bar之Contextual action bar

    

两张图，前一张是没有显示contextual action bar 的时候，后面那张是用户长点击EditText显示contextual action bar的效果。contextual action bar 也能加入menu item 并对menu item 进行监听。在contextual action bar 中显示 menu item 需要在 /res/menu/ 文件夹中加入布局文件。

代码：

 

package com.example.demo_actionbarcontextual;

import com.example.demo_actionbarcontextual.R;
import android.app.Activity;
import android.os.Bundle;
import android.view.ActionMode;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends Activity {
    protected Object mActionMode;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        View view = findViewById(R.id.myView);

        // 对EditText设置长点击事件，用来显示 contextual action bar
        view.setOnLongClickListener(new View.OnLongClickListener() {
            public boolean onLongClick(View view) {
                if (mActionMode != null) {
                    return false;
                }

                // Start the Contextual Action Bar using the ActionMode.Callback defined above
                mActionMode = MainActivity.this
                        .startActionMode(mActionModeCallback);
                view.setSelected(true);
                return true;
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.mainmenu, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        Toast.makeText(this, "Just a test", Toast.LENGTH_SHORT).show();
        return true;
    }

    private ActionMode.Callback mActionModeCallback = new ActionMode.Callback() {

        // Called when the action mode is created; startActionMode() was called
        public boolean onCreateActionMode(ActionMode mode, Menu menu) {
            // Inflate a menu resource providing context menu items
            MenuInflater inflater = mode.getMenuInflater();
            // R.menu.contextual 是 contextual action bar 的布局文件， 在 /res/menu/ 文件夹下
            inflater.inflate(R.menu.contextual, menu);
            return true;
        }

        // Called each time the action mode is shown. Always called after
        // onCreateActionMode, but
        // may be called multiple times if the mode is invalidated.
        public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
            return false; // Return false if nothing is done
        }

        // 当用户点击 contextual action bar 的 menu item 的时候产生点击事件
        public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
            switch (item.getItemId()) {
            case R.id.toast:
                Toast.makeText(MainActivity.this, "Selected menu",
                        Toast.LENGTH_LONG).show();
                mode.finish(); // 关闭 contextual action bar
                return true;
            default:
                return false;
            }
        }

        // Called when the user exits the action mode
        public void onDestroyActionMode(ActionMode mode) {
            mActionMode = null;
        }
    };

}

下载：Demo_ActionBarContextual

 

Action bar 之 navigation tabs

左图是竖直屏幕的效果，右图是横屏的效果:

  

代码：

 

package de.arvidg.exampleactionbartabs;

import android.app.ActionBar;
import android.app.ActionBar.Tab;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentTransaction;
import android.content.Context;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.Toast;

public class StartActivity extends Activity {
    public static Context appContext;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        appContext = getApplicationContext();

        // ActionBar
        ActionBar actionbar = getActionBar();
        // 设置action bar 的 navigation mode
        actionbar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

        // 添加 action bar 的 tabs
        ActionBar.Tab PlayerTab = actionbar.newTab().setText("Fragment A");
        ActionBar.Tab StationsTab = actionbar.newTab().setText("Fragment B");

        // 实例化 fragment action bar 是用 fragment 来显示的
        Fragment PlayerFragment = new AFragment();
        Fragment StationsFragment = new BFragment();

        // 对 tabs 设置监听事件
        PlayerTab.setTabListener(new MyTabsListener(PlayerFragment));
        StationsTab.setTabListener(new MyTabsListener(StationsFragment));

        // 最后把 tabs 加入监听事件
        actionbar.addTab(PlayerTab);
        actionbar.addTab(StationsTab);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        case R.id.menuitem_search:
            Toast.makeText(appContext, "search", Toast.LENGTH_SHORT).show();
            return true;
        case R.id.menuitem_add:
            Toast.makeText(appContext, "add", Toast.LENGTH_SHORT).show();
            return true;
        case R.id.menuitem_share:
            Toast.makeText(appContext, "share", Toast.LENGTH_SHORT).show();
            return true;
        case R.id.menuitem_feedback:
            Toast.makeText(appContext, "feedback", Toast.LENGTH_SHORT).show();
            return true;
        case R.id.menuitem_about:
            Toast.makeText(appContext, "about", Toast.LENGTH_SHORT).show();
            return true;
        case R.id.menuitem_quit:
            Toast.makeText(appContext, "quit", Toast.LENGTH_SHORT).show();
            return true;
        }
        return false;
    }

    // @Override
    // protected void onSaveInstanceState(Bundle outState) {
    // super.onSaveInstanceState(outState);
    // outState.putInt("tab", getActionBar().getSelectedNavigationIndex());
    // }

}

// 实例化 tabs 的监听类
class MyTabsListener implements ActionBar.TabListener {
    public Fragment fragment;

    // 传入监听的 tab 的 fragment
    public MyTabsListener(Fragment fragment) {
        this.fragment = fragment;
    }


    // 重复两次以上点击 tab
    @Override
    public void onTabReselected(Tab tab, FragmentTransaction ft) { // ft 用来控制 fragment
        Toast.makeText(StartActivity.appContext, "Reselected!",
                Toast.LENGTH_SHORT).show();
    }

    // 就点击一次
    @Override
    public void onTabSelected(Tab tab, FragmentTransaction ft) {
        ft.replace(R.id.fragment_container, fragment);
    }

    // 不点击
    @Override
    public void onTabUnselected(Tab tab, FragmentTransaction ft) {
        ft.remove(fragment);
    }

 

Action bar 之 ShareActionProvider

1.首先要在menu布局文件的item标签中加入
android:actionProviderClass="android.widget.ShareActionProvider"
2.得到ShareActionProvider的实例
provider = (ShareActionProvider) menu.findItem(R.id.menu_share)
.getActionProvider();
3.设置Intent
效果图：

代码:

 

package com.example.demo_shareactionprovider;

import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ShareActionProvider;

public class MainActivity extends Activity {
    ShareActionProvider provider = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.activity_main, menu);


        // Get the ActionProvider
        provider = (ShareActionProvider) menu.findItem(R.id.menu_share)
                .getActionProvider();
        // Initialize the share intent
        Intent intent = new Intent(Intent.ACTION_SEND);
        intent.setType("text/plain");
        intent.putExtra(Intent.EXTRA_TEXT, "Text I want to share");
        provider.setShareIntent(intent);

        return true;
    }



    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        case R.id.menu_share:
            break;
        default:
            break;
        }
        return super.onOptionsItemSelected(item);
    }
}

 

 

/res/menu/activity_main.xml

<menu xmlns:android="http://schemas.android.com/apk/res/android" >

    <item
        android:id="@+id/menu_share"
        android:actionProviderClass="android.widget.ShareActionProvider"
        android:showAsAction="ifRoom"
        android:title="Share"/>
    <item
        android:id="@+id/item1"
        android:icon="@android:drawable/ic_menu_call"
        android:showAsAction="ifRoom"
        android:title="">
    </item>

</menu>

The ShareActionProvider now handles all user interaction with the item and you do not need to handle click events from the onOptionsItemSelected() callback method.
上面是官方文档上给的: 就是说无需在onOptionsItemSelected()这个回调方法中再去处理了。

代码：Demo_ShareActionProvider

Action Bar 之 style

你可以用android的style和theme来自定义action bar的风格和主题

android:windowActionBarOverlay 这个属性是用来定义actionbar和其下方视图的位置关系的。默认false，当设置成true时，表示activity layout 就是说你的下方的视图将覆盖整个屏幕。这样设置的好处就是说，当你隐藏action bar的时候，视图不会改变位置。当我们把action bar设置成半透明的时候，我们也能看见其下面的内容，这样的界面对用户来说更加有好。

<SomeView  android:layout_marginTop="?android:attr/actionBarSize" />

上面这个属性可以设置activity layout距离屏幕顶端的距离。这样设置可以防止被action bar覆盖下方内容。

下面是一个简单的关于如何改变antion bar 字体、分割图片、背景的一个style

 

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <!-- the theme applied to the application or activity -->
    <style name="CustomActivityTheme" parent="@android:style/Theme.Holo">
        <item name="android:actionBarTabTextStyle">@style/CustomTabTextStyle</item>
        <item name="android:actionBarDivider">@drawable/ab_divider</item>
        <item name="android:actionBarItemBackground">@drawable/ab_item_background</item>
    </style>

    <!-- style for the action bar tab text -->
    <style name="CustomTabTextStyle" parent="@android:style/TextAppearance.Holo">
        <item name="android:textColor">#2456c2</item>
    </style>
</resources>

 

 

能设置的关于action bar的风格（style）的属性有：

android:actionButtonStyle // Defines a style resource for the action item buttons.

android:actionBarItemBackground //Defines a drawable resource for each action item's background. (Addedin API level 14.)

android:itemBackground // Defines a drawable resource for each overflow menu item's background.

android:actionBarDivider // Defines a drawable resource for the divider between action items.(Added in API level 14.)

android:actionMenuTextColor //Defines a color for text that appears in an action item.

android:actionMenuTextAppearance //Defines a style resource for text that appears in an action item.

android:actionBarWidgetTheme //Defines a theme resource for widgets that are inflated into the actionbar as action views. (Added in API level 14.)

 

下面的网址是源码中的styles.xml和themes.xml文件，包含了系统中所有的样式和主题。根据自己的需要可以改变action bar的显示风格。

https://android.googlesource.com/platform/frameworks/base/+/refs/heads/master/core/res/res/values/styles.xml

https://android.googlesource.com/platform/frameworks/base/+/refs/heads/master/core/res/res/values/themes.xml

 

例子1：怎么改变tab的字体大小、字体颜色等

 

 

<pre name="code" class="html">在themes.xml文件中关于tab的属性有：</pre><br>
<br>
<pre></pre>
<pre name="code" class="html">android:actionBarTabStyle // Defines a style resource for tabs in the action bar.</pre>android:actionBarTabBarStyle // Defines a style resource for the thin bar that appears below the navigation tabs.<br>
android:actionBarTabTextStyle //Defines a style resource for text in the navigation tabs.
<p><br>
</p>
<p>在themes.xml文件中找到：</p>
<p></p>
<p></p>
<pre name="code" class="html"><itemnameitemname="actionBarTabTextStyle">@style/Widget.Holo.Light.ActionBar.TabText</item></pre>
<p></p>
<p>在style.xml文件中找到</p>
<pre name="code" class="html"><style name="Widget.Holo.Light.ActionBar.TabText" parent="Widget.Holo.ActionBar.TabText">
</pre>
<p><br>
</p>
在style.xml文件中通过Widget.Holo.ActionBar.TabText，我们可以找到下面<br>
<pre name="code" class="html"><style name="Widget.Holo.ActionBar.TabText" parent="Widget.ActionBar.TabText">
    <item name="android:textAppearance">@style/TextAppearance.Holo.Medium</item>
    <item name="android:textColor">?android:attr/textColorPrimary</item>
    <item name="android:textSize">12sp</item>
    <item name="android:textStyle">bold</item>
    <item name="android:textAllCaps">true</item>
    <item name="android:ellipsize">marquee</item>
    <item name="android:maxLines">2</item>
</style>
</pre>
<p><br>
</p>
<p>下面是我们工程中styles.xml的内容:<br>
</p>
<pre name="code" class="html"><?xml version="1.0" encoding="utf-8"?>
<resources xmlns:android="http://schemas.android.com/apk/res/android">

    <style name="CustomActivityThemo" parent="@android:style/Theme.Holo.Light">
        <item name="android:actionBarTabTextStyle">@style/CustomTabTextStyle</item>
    </style>

    <style name="CustomTabTextStyle" parent="@android:style/Widget.ActionBar.TabText">
        <item name="android:textSize">25sp</item>
        <item name="android:textColor">#FF0000</item>
        <item name="android:textStyle">italic|bold</item>
    </style>

</resources>
</pre><br>
我们必须在manifest.xml文件中的activity标签中设置<br>
<br>
<p></p>
<pre name="code" class="html"><activity

<span style="white-space:pre">  </span>android:theme="@style/CustomActivityThemo" ></pre><pre name="code" class="html"><span style="white-space:pre">    </span>....
</activity>
</pre>
<p></p>
<p><br>
</p>
代码：Demo_ActionBarTabsColor<br>
<p><br>
</p>
<p>例子2：改变action bar中tab的indicator（下面的那条横线）的颜色<br>
styles.xml文件内容:</p>
<p><br>
</p>
<pre name="code" class="html"><?xml version="1.0" encoding="utf-8"?>
<resources xmlns:android="http://schemas.android.com/apk/res/android">

    <!-- the theme applied to the application or activity -->
    <style name="CustomActivityTheme" parent="@android:style/Theme.Holo.Light">
        <item name="android:actionBarTabTextStyle">@style/CustomTabTextStyle</item>
        <item name="android:actionBarTabBarStyle">@android:color/holo_orange_dark</item>
        <item name="android:actionBarTabStyle">@style/ActionBarTabStyle.Example</item>
    </style>

    <!-- style for the action bar tab text -->
    <style name="CustomTabTextStyle" parent="@android:style/TextAppearance.Holo">
        <item name="android:textColor">#2456c2</item>
    </style>

    <style name="ActionBarTabStyle.Example" parent="@android:style/Widget.Holo.Light.ActionBar.TabView">
        <item name="android:background">@drawable/tab_indicator_ab_example</item>
    </style>

</resources>
</pre><br>
<br>
<p></p>
<p>android:background这个属性定义了tab的显示风格，对应的是一个xml文件不是图片<br>
</p>
<p></p>
<p><br>
</p>
<p><br>
</p>
<p>tab_indicator_ab_example.xml文件的内容：</p>
<p></p>
<pre name="code" class="html"><?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <!-- Non focused states -->
    <item android:drawable="@android:color/transparent" android:state_focused="false" android:state_pressed="false" android:state_selected="false"/>
    <item android:drawable="@drawable/tab_selected_example" android:state_focused="false" android:state_pressed="false" android:state_selected="true"/>

    <!-- Focused states -->
    <item android:drawable="@drawable/tab_unselected_focused_example" android:state_focused="true" android:state_pressed="false" android:state_selected="false"/>
    <item android:drawable="@drawable/tab_selected_focused_example" android:state_focused="true" android:state_pressed="false" android:state_selected="true"/>

    <!-- Pressed -->
    <!-- Non focused states -->
    <item android:drawable="@drawable/tab_unselected_pressed_example" android:state_focused="false" android:state_pressed="true" android:state_selected="false"/>
    <item android:drawable="@drawable/tab_selected_pressed_example" android:state_focused="false" android:state_pressed="true" android:state_selected="true"/>

    <!-- Focused states -->
    <item android:drawable="@drawable/tab_unselected_pressed_example" android:state_focused="true" android:state_pressed="true" android:state_selected="false"/>
    <item android:drawable="@drawable/tab_selected_pressed_example" android:state_focused="true" android:state_pressed="true" android:state_selected="true"/>

</selector>
</pre><pre name="code" class="html"></pre>代码：Demo_ActionBarTabsColor<p></p><p>参考文献：</p><p>http://www.vogella.com/articles/AndroidActionBar/article.htmlhttp://developer.android.com/guide/topics/ui/actionbar.html</p><p></p>