Android中ActionBar的使用方式

虽然ActionBar已经有一些过时，现在是ToolBar的天下了，但是觉得ToolBar还是不太会用，以后有空再去看ToolBar

俗话说：最好还是google官方原文档。。（其实是我自己说的）

ActionBar是从Android 3.0(API level 11)，使用Theme.Holo theme，其最小的SDK版本是11，即：

<manifest ... >
    <uses-sdk android:minSdkVersion="11" ... />
    ...
</manifest>

为了向下兼容，google发布了 v7 appcompat库，作为新时代人类我们当然用Android Studio 省去引入V7包的过程。

1.让我们的Activity继承ActionBarActivity

public class MainActivity extends ActionBarActivity { ... }

2.修改主题

<activity android:theme="@style/Theme.AppCompat.Light" ... >

3.可以修改兼容到Android2.1

<manifest ... >
    <uses-sdk android:minSdkVersion="7"  android:targetSdkVersion="18" />
    ...
</manifest>

4.在 res/menu/添加menu文件，如：

<menu xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:yourapp="http://schemas.android.com/apk/res-auto" >
    <!-- Search, should appear as action button -->
    <item android:id="@+id/action_search"
          android:icon="@drawable/ic_action_search"
          android:title="@string/action_search"
          yourapp:showAsAction="ifRoom"  />
    ...
</menu>

5.放置menu条目到actionBar，包括其回调

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu items for use in the action bar
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.main_activity_actions, menu);
    return super.onCreateOptionsMenu(menu);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle presses on the action bar items
    switch (item.getItemId()) {
        case R.id.action_search:
            openSearch();
            return true;
        case R.id.action_settings:
            openSettings();
            return true;
        default:
            return super.onOptionsItemSelected(item);
    }
}

6.为低版本添加返回按钮、在清单文件中配置即可

<application ... >
    ...
    <!-- The main/home activity (it has no parent activity) -->
    <activity
        android:name="com.example.myfirstapp.MainActivity" ...>
        ...
    </activity>
    <!-- A child of the main activity -->
    <activity
        android:name="com.example.myfirstapp.DisplayMessageActivity"
        android:label="@string/title_activity_display_message"
        android:parentActivityName="com.example.myfirstapp.MainActivity" >
        <!-- Parent activity meta-data to support 4.0 and lower -->
        <meta-data
            android:name="android.support.PARENT_ACTIVITY"
            android:value="com.example.myfirstapp.MainActivity" />
    </activity>
</application>

也可以是用app图标作为返回button

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

    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    // 如果最低版本高于11使用如下
    // getActionBar().setDisplayHomeAsUpEnabled(true);
}

7.给ActionBar添加Tab标签
创建文件res/drawable/actionbar_tab_indicator.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

<!-- STATES WHEN BUTTON IS NOT PRESSED -->

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

    <!-- Focused states (such as when focused with a d-pad or mouse hover) -->
    <item android:state_focused="true" android:state_selected="false"
          android:state_pressed="false"
          android:drawable="@drawable/tab_unselected_focused" />
    <item android:state_focused="true" android:state_selected="true"
          android:state_pressed="false"
          android:drawable="@drawable/tab_selected_focused" />

<!-- STATES WHEN BUTTON IS PRESSED -->

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

    <!-- Focused states (such as when focused with a d-pad or mouse hover) -->
    <item android:state_focused="true" android:state_selected="false"
          android:state_pressed="true"
          android:drawable="@drawable/tab_unselected_pressed" />
    <item android:state_focused="true" android:state_selected="true"
          android:state_pressed="true"
          android:drawable="@drawable/tab_selected_pressed" />
</selector>

在创建文件res/values/themes.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <!-- the theme applied to the application or activity -->
    <style name="CustomActionBarTheme"
           parent="@style/Theme.AppCompat">
        <item name="android:actionBarTabStyle">@style/MyActionBarTabs</item>

        <!-- Support library compatibility -->
        <item name="actionBarTabStyle">@style/MyActionBarTabs</item>
    </style>

    <!-- ActionBar tabs styles -->
    <style name="MyActionBarTabs"
           parent="@style/Widget.AppCompat.ActionBar.TabView">
        <!-- tab indicator -->
        <item name="android:background">@drawable/actionbar_tab_indicator</item>

        <!-- Support library compatibility -->
        <item name="background">@drawable/actionbar_tab_indicator</item>
    </style>
</resources>

修改MainActivity主题样式为CustomActionBarTheme

最后代码中调用、

 actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

        ActionBar.Tab tab1 = actionBar.newTab();
        tab1.setText("标签一").setTabListener(new MyTabListner());
        actionBar.addTab(tab1);
        ActionBar.Tab tab2 = actionBar.newTab();
        tab2.setText("标签二").setTabListener(new MyTabListner());
        actionBar.addTab(tab2);
        ActionBar.Tab tab3 = actionBar.newTab();
        tab3.setText("标签三").setTabListener(new MyTabListner());
        actionBar.addTab(tab3);

 private class MyTabListner implements ActionBar.TabListener{

        @Override
        public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft) {

        }

        @Override
        public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction ft) {

        }

        @Override
        public void onTabReselected(ActionBar.Tab tab, FragmentTransaction ft) {

        }
    }

8.给ActionBar添加抽屉，使用DrawLayout
布局文件：（注意DrawLayout为android.support.v4.widget.DrawerLayout）

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">
    </LinearLayout>

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        android:background="@drawable/bg_tab"
        >

    </FrameLayout>
</android.support.v4.widget.DrawerLayout>

在MainActivity中

drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
actionBar.setDisplayHomeAsUpEnabled(true);
        actionBar.setHomeButtonEnabled(true);

//这里我看源码第三个参数确实为drawer indicator，但是并没有修改成功，还是原始的一个箭头，待解决：TODO:
        drawerToggle = new ActionBarDrawerToggle(this, drawerLayout, R.drawable.ic_drawer_am, R.string.open_drawer, R.string.close_drawer);
        drawerLayout.setDrawerListener(drawerToggle);
        //  让开关和actionbar建立关系
        drawerToggle.syncState();

点击事件自己出来修改return

public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.action_search:
                Toast.makeText(this, "搜索", Toast.LENGTH_SHORT).show();
                return true;
            default:

                return drawerToggle.onOptionsItemSelected(item) | super.onOptionsItemSelected(item);
        }
    }

9.Tab标签与ViewPager的绑定，其实就是分别对其设置select监听事件

//给ViewPager设置适配器
        mViewPager.setAdapter(new MainPagerAdapter(getSupportFragmentManager()));

private class MainPagerAdapter extends FragmentStatePagerAdapter {

        public MainPagerAdapter(FragmentManager fm) {
            super(fm);
        }

        @Override
        public Fragment getItem(int position) {
            //Fagment的List集合
        }

        @Override
        public int getCount() {
            return 3;
        }

//给ViewPager和tab设置监听事件进行绑定
        mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
            @Override
            public void onPageSelected(int position) {
                super.onPageSelected(position);
                getSupportActionBar().setSelectedNavigationItem(position);
            }
        });

/**
         * ActionBar标签的监听事件
         */
        private class MyTabListner implements ActionBar.TabListener {

            @Override
            public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft) {
                //给ViewPager和tab设置监听事件进行绑定
                mViewPager.setCurrentItem(tab.getPosition(), false);
            }

            @Override
            public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction ft) {

            }

            @Override
            public void onTabReselected(ActionBar.Tab tab, FragmentTransaction ft) {

            }
    }

遇到的一些问题：

actionBar中不显示app图标：
添加：

getSupportActionBar().setDisplayOptions(ActionBar.DISPLAY_SHOW_HOME | ActionBar.DISPLAY_SHOW_TITLE);
getSupportActionBar().setIcon(R.mipmap.ic_launcher);