Action Bar示例代码 (一)

今天一起来看下Android Action Bar的示例代码，我们通过活动栏做一个简单选项菜单。下面这个例子将演示ActionBar.NAVIGATION_MODE_STANDARD、ActionBar.NAVIGATION_MODE_TABS和                     : ActionBar.NAVIGATION_MODE_STANDARD等模式的效果。最后Android123仍然提示大家Action Bar是Android 3.0 honeycomb才开始有的特性，老版本的SDK和固件无法使用。

public class ActionBarDisplayOptions extends Activity  implements View.OnClickListener, ActionBar.TabListener {     private View mCustomView;

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

        findViewById(R.id.toggle_home_as_up).setOnClickListener(this);         findViewById(R.id.toggle_show_home).setOnClickListener(this);         findViewById(R.id.toggle_use_logo).setOnClickListener(this);         findViewById(R.id.toggle_show_title).setOnClickListener(this);         findViewById(R.id.toggle_show_custom).setOnClickListener(this);         findViewById(R.id.toggle_navigation).setOnClickListener(this);         findViewById(R.id.cycle_custom_gravity).setOnClickListener(this);

        mCustomView = getLayoutInflater().inflate(R.layout.action_bar_display_options_custom, null);           final ActionBar bar = getActionBar();         bar.setCustomView(mCustomView,                 new ActionBar.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));

        bar.addTab(bar.newTab().setText("Tab 1").setTabListener(this));         bar.addTab(bar.newTab().setText("Tab 2").setTabListener(this));         bar.addTab(bar.newTab().setText("Tab 3").setTabListener(this));     }

    @Override     public boolean onCreateOptionsMenu(Menu menu) {         getMenuInflater().inflate(R.menu.display_options_actions, menu);         return true;     }

    public void onClick(View v) {         final ActionBar bar = getActionBar();         int flags = 0;         switch (v.getId()) {             case R.id.toggle_home_as_up:                 flags = ActionBar.DISPLAY_HOME_AS_UP;                 break;             case R.id.toggle_show_home:                 flags = ActionBar.DISPLAY_SHOW_HOME;                 break;             case R.id.toggle_use_logo:                 flags = ActionBar.DISPLAY_USE_LOGO;                 break;             case R.id.toggle_show_title:                 flags = ActionBar.DISPLAY_SHOW_TITLE;                 break;             case R.id.toggle_show_custom:                 flags = ActionBar.DISPLAY_SHOW_CUSTOM;                 break;

            case R.id.toggle_navigation:                 bar.setNavigationMode(                         bar.getNavigationMode() == ActionBar.NAVIGATION_MODE_STANDARD                                 ? ActionBar.NAVIGATION_MODE_TABS                                 : ActionBar.NAVIGATION_MODE_STANDARD);                 return;             case R.id.cycle_custom_gravity:                 ActionBar.LayoutParams lp = (ActionBar.LayoutParams) mCustomView.getLayoutParams();                 int newGravity = 0;                 switch (lp.gravity & Gravity.HORIZONTAL_GRAVITY_MASK) {                     case Gravity.LEFT:                         newGravity = Gravity.CENTER_HORIZONTAL;                         break;                     case Gravity.CENTER_HORIZONTAL:                         newGravity = Gravity.RIGHT;                         break;                     case Gravity.RIGHT:                         newGravity = Gravity.LEFT;                         break;                 }                 lp.gravity = lp.gravity & ~Gravity.HORIZONTAL_GRAVITY_MASK | newGravity;                 bar.setCustomView(mCustomView, lp);                 return;         }

        int change = bar.getDisplayOptions() ^ flags;         bar.setDisplayOptions(change, flags);     }

    public void onTabSelected(Tab tab, FragmentTransaction ft) {     }

    public void onTabUnselected(Tab tab, FragmentTransaction ft) {     }

    public void onTabReselected(Tab tab, FragmentTransaction ft) {     } }

 接下来是文中涉及的3个xml布局文件:

 相关的XML布局action_bar_display_options.xml代码为

 <?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:Android="http://schemas.android.com/apk/res/android"               android:layout_width="match_parent"               android:layout_height="match_parent"               android:orientation="vertical">     <Button android:id="@+id/toggle_home_as_up"             android:layout_width="wrap_content"             android:layout_height="wrap_content"             android:text="@string/toggle_home_as_up" />     <Button android:id="@+id/toggle_show_home"             android:layout_width="wrap_content"             android:layout_height="wrap_content"             android:text="@string/toggle_show_home" />     <Button android:id="@+id/toggle_use_logo"             android:layout_width="wrap_content"             android:layout_height="wrap_content"             android:text="@string/toggle_use_logo" />     <Button android:id="@+id/toggle_show_title"             android:layout_width="wrap_content"             android:layout_height="wrap_content"             android:text="@string/toggle_show_title" />     <Button android:id="@+id/toggle_show_custom"             android:layout_width="wrap_content"             android:layout_height="wrap_content"             android:text="@string/toggle_show_custom" />     <Button android:id="@+id/toggle_navigation"             android:layout_width="wrap_content"             android:layout_height="wrap_content"             android:text="@string/toggle_navigation" />     <Button android:id="@+id/cycle_custom_gravity"             android:layout_width="wrap_content"             android:layout_height="wrap_content"             android:text="@string/cycle_custom_gravity" /> </LinearLayout>

相关的自定义布局文件action_bar_display_options_custom.xml代码为

<?xml version="1.0" encoding="utf-8"?>

<Button xmlns:android="http://schemas.android.com/apk/res/android"         android:text="@string/display_options_custom_button" />

相关的menu布局xml文件display_options_actions.xml代码为

 <?xml version="1.0" encoding="utf-8"?>

<menu xmlns:android="http://schemas.android.com/apk/res/android">     <item android:id="@+id/simple_item"           android:title="@string/display_options_menu_item" /> </menu>

  上面的string后的元素大家可以根据自己的情况进行替换。