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 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);
    }
}

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) -->
    <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>

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