Training-ActionBar

阅读：http://developer.android.com/training/basics/actionbar/index.html

对于API11以下的兼容：

1. Update your activity so that it extends ActionBarActivity. For example:

   public class Main Activit yextends ActionBarActivity{...}

2. In your manifest file, update either the <application> element or individual <activity> elements to use one of the Theme.AppCompat themes. For example:

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

   Note: If you've created a custom theme, be sure it uses one of the Theme.AppCompat themes as its parent. For details, see Styling the Action Bar.

 

首先，需要定义一个menu的布局文件：

<menu xmlns:android="http://schemas.android.com/apk/res/android" ><!-- Search, should appear as action button --><item android:id="@+id/action_search"android:icon="@drawable/ic_action_search"android:title="@string/action_search"android:showAsAction="ifRoom" /><!-- Settings, should always be in the overflow --><item android:id="@+id/action_settings"android:title="@string/action_settings"android:showAsAction="never" />
</menu>

接下来覆盖两个方法：

public boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu items for use in the action barMenuInflater 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 itemsswitch (item.getItemId()) {case R.id.action_search:openSearch();return true;case R.id.action_settings:openSettings();return true;default:return super.onOptionsItemSelected(item);}
}

使得按钮出现并有所响应。

 

The Up button in Gmail.

首先定义父Activity

<application ... >...<!-- The main/home activity (it has no parent activity) --><activityandroid:name="com.example.myfirstapp.MainActivity" ...>...</activity><!-- A child of the main activity --><activityandroid: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-dataandroid:name="android.support.PARENT_ACTIVITY"android:value="com.example.myfirstapp.MainActivity" /></activity>
</application>

接下来代码里呈现：

@Override
public void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_displaymessage);getSupportActionBar().setDisplayHomeAsUpEnabled(true);// If your minSdkVersion is 11 or higher, instead use:// getActionBar().setDisplayHomeAsUpEnabled(true);
}

 

关于样式的配置，http://developer.android.com/training/basics/actionbar/styling.html 有详细的介绍。

关于ActionBar覆盖在内容上面的，可看：http://developer.android.com/training/basics/actionbar/overlaying.html