Action Bar示例代码 (一)

[honeymoose]

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"?>

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"?>

相关的menu布局xml文件display_options_actions.xml代码为

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

上面的string后的元素大家可以根据自己的情况进行替换。