修改Actionbar的样式

本例几乎涵盖了有关Actionbar的所有操作，由于前面介绍过tabs和item，这里重点介绍Actionbar的样式修改，需要源工程的请在资源里下载styleactionbar。更多请阅读http://android-developers.blogspot.com/2011/04/customizing-action-bar.html

1、首先准备一个RoundedColourFragment，前面介绍过各部分的作用，这里就不赘述。

 import android.app.Fragment;
 import android.graphics.drawable.GradientDrawable;
 import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.ViewGroup.LayoutParams;
 import android.widget.LinearLayout;

 public class RoundedColourFragment extends Fragment {

     private View mView;
     private int mColour;
     private float mWeight;
     private int marginLeft, marginRight, marginTop, marginBottom;

     // need a public empty constructor for framework to instantiate
     public RoundedColourFragment() {

     }

     public RoundedColourFragment(int colour, float weight, int margin_left,
             int margin_right, int margin_top, int margin_bottom) {
         mColour = colour;
         mWeight = weight;
         marginLeft = margin_left;
         marginRight = margin_right;
         marginTop = margin_top;
         marginBottom = margin_bottom;
     }

     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         mView = new View(getActivity());

         GradientDrawable background = (GradientDrawable) getResources()
                 .getDrawable(R.drawable.rounded_rect);
         background.setColor(mColour);

         mView.setBackgroundDrawable(background);
         LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(0,
                 LayoutParams.FILL_PARENT, mWeight);
         lp.setMargins(marginLeft, marginTop, marginRight, marginBottom);
         mView.setLayoutParams(lp);
     }

     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container,
             Bundle savedInstanceState) {
         return mView;
     }

 }

2、MainActivity.java文件，主要是创建tabs、item、drop down navigation等，以及他们之间相互转换的控制逻辑，一部分内容前面也介绍过。

 import android.animation.ObjectAnimator;
 import android.app.ActionBar;
 import android.app.Activity;
 import android.app.FragmentTransaction;
 import android.app.ActionBar.OnNavigationListener;
 import android.os.Bundle;
 import android.os.Handler;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.MenuItem.OnMenuItemClickListener;
 import android.widget.ArrayAdapter;

 public class MainActivity extends Activity implements ActionBar.TabListener {

     private final Handler handler = new Handler();
     private RoundedColourFragment leftFrag;
     private RoundedColourFragment rightFrag;
     private boolean useLogo = false;
     private boolean showHomeUp = false;

     /** Called when the activity is first created. */
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.main);
         final ActionBar ab = getActionBar();

         // set defaults for logo & home up
         ab.setDisplayHomeAsUpEnabled(showHomeUp);
         ab.setDisplayUseLogoEnabled(useLogo);

         // set up tabs nav
         for (int i = 1; i < 4; i++) {
             ab.addTab(ab.newTab().setText("Tab " + i).setTabListener(this));
         }

         // set up list nav
         ab.setListNavigationCallbacks(ArrayAdapter
                 .createFromResource(this, R.array.sections,
                         android.R.layout.simple_spinner_dropdown_item),
                 new OnNavigationListener() {
                     public boolean onNavigationItemSelected(int itemPosition,
                             long itemId) {
                         // FIXME add proper implementation
                         rotateLeftFrag();
                         return false;
                     }
                 });

         // default to tab navigation
         showTabsNav();

         // create a couple of simple fragments as placeholders
         final int MARGIN = 16;
         leftFrag = new RoundedColourFragment(getResources().getColor(
                 R.color.android_green), 1f, MARGIN, MARGIN / 2, MARGIN, MARGIN);
         rightFrag = new RoundedColourFragment(getResources().getColor(
                 R.color.honeycombish_blue), 2f, MARGIN / 2, MARGIN, MARGIN,
                 MARGIN);

         FragmentTransaction ft = getFragmentManager().beginTransaction();
         ft.add(R.id.root, leftFrag);
         ft.add(R.id.root, rightFrag);
         ft.commit();
     }

     @Override
     public boolean onCreateOptionsMenu(Menu menu) {
         getMenuInflater().inflate(R.menu.main_menu, menu);

         // set up a listener for the refresh item
         final MenuItem refresh = (MenuItem) menu.findItem(R.id.menu_refresh);
         refresh.setOnMenuItemClickListener(new OnMenuItemClickListener() {
             // on selecting show progress spinner for 1s
             public boolean onMenuItemClick(MenuItem item) {
                 // item.setActionView(R.layout.progress_action);
                 handler.postDelayed(new Runnable() {
                     public void run() {
                         refresh.setActionView(null);
                     }
                 }, 1000);
                 return false;
             }
         });
         return super.onCreateOptionsMenu(menu);
     }

     @Override
     public boolean onOptionsItemSelected(MenuItem item) {
         switch (item.getItemId()) {
         case android.R.id.home:
             // TODO handle clicking the app icon/logo
             return false;
         case R.id.menu_refresh:
             // switch to a progress animation
             item.setActionView(R.layout.indeterminate_progress_action);
             return true;
         case R.id.menu_both:
             // rotation animation of green fragment
             rotateLeftFrag();
             return true;
         case R.id.menu_text:
             // alpha animation of blue fragment
             ObjectAnimator alpha = ObjectAnimator.ofFloat(rightFrag.getView(),
                     "alpha", 1f, 0f);
             alpha.setRepeatMode(ObjectAnimator.REVERSE);
             alpha.setRepeatCount(1);
             alpha.setDuration(800);
             alpha.start();
             return true;
         case R.id.menu_logo:
             useLogo = !useLogo;
             item.setChecked(useLogo);
             getActionBar().setDisplayUseLogoEnabled(useLogo);
             return true;
         case R.id.menu_up:
             showHomeUp = !showHomeUp;
             item.setChecked(showHomeUp);
             getActionBar().setDisplayHomeAsUpEnabled(showHomeUp);
             return true;
         case R.id.menu_nav_tabs:
             item.setChecked(true);
             showTabsNav();
             return true;
         case R.id.menu_nav_label:
             item.setChecked(true);
             showStandardNav();
             return true;
         case R.id.menu_nav_drop_down:
             item.setChecked(true);
             showDropDownNav();
             return true;
         case R.id.menu_bak_none:
             item.setChecked(true);
             getActionBar().setBackgroundDrawable(null);
             return true;
         case R.id.menu_bak_gradient:
             item.setChecked(true);
             getActionBar().setBackgroundDrawable(getResources().getDrawable(R.drawable.ad_action_bar_gradient_bak));
             return true;
         default:
             return super.onOptionsItemSelected(item);
         }
     }

     private void rotateLeftFrag() {
         if (leftFrag != null) {
             ObjectAnimator.ofFloat(leftFrag.getView(), "rotationY", 0, 180)
                     .setDuration(500).start();
         }
     }

     private void showStandardNav() {
         ActionBar ab = getActionBar();
         if (ab.getNavigationMode() != ActionBar.NAVIGATION_MODE_STANDARD) {
             ab.setDisplayShowTitleEnabled(true);
             ab.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
         }
     }

     private void showDropDownNav() {
         ActionBar ab = getActionBar();
         if (ab.getNavigationMode() != ActionBar.NAVIGATION_MODE_LIST) {
             ab.setDisplayShowTitleEnabled(false);
             ab.setNavigationMode(ActionBar.NAVIGATION_MODE_LIST);
         }
     }

     private void showTabsNav() {
         ActionBar ab = getActionBar();
         if (ab.getNavigationMode() != ActionBar.NAVIGATION_MODE_TABS) {
             ab.setDisplayShowTitleEnabled(false);
             ab.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
         }
     }

     public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft) {
         // FIXME add a proper implementation, for now just rotate the left
         // fragment
         rotateLeftFrag();
     }

     public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction ft) {
         // FIXME implement this
     }

     public void onTabReselected(ActionBar.Tab tab, FragmentTransaction ft) {
         // FIXME implement this
     }

 }

3、在res/values下的styles.xml文件，这里是本程序讲解的核心，也是actionbar样式转换的核心，java代码如下：

 "1.0" encoding="utf-8"?>



     "Theme" parent="android:Theme">



     "Theme.AndroidDevelopers" parent="android:style/Theme.Holo.Light">

         "android:selectableItemBackground">@drawable/ad_selectable_background

         "android:popupMenuStyle">@style/MyPopupMenu
         "android:dropDownListViewStyle">@style/MyDropDownListView
         "android:actionBarTabStyle">@style/MyActionBarTabStyle
         "android:actionDropDownStyle">@style/MyDropDownNav
         "android:listChoiceIndicatorMultiple">@drawable/ad_btn_check_holo_light
         "android:listChoiceIndicatorSingle">@drawable/ad_btn_radio_holo_light




     "MyPopupMenu" parent="android:style/Widget.Holo.Light.ListPopupWindow">
         "android:popupBackground">@drawable/ad_menu_dropdown_panel_holo_light



     "MyDropDownListView" parent="android:style/Widget.Holo.ListView.DropDown">
         "android:listSelector">@drawable/ad_selectable_background



     "MyActionBarTabStyle" parent="android:style/Widget.Holo.Light.ActionBarView_TabView">
         "android:background">@drawable/actionbar_tab_bg
         "android:paddingLeft">32dp
         "android:paddingRight">32dp



     "MyDropDownNav" parent="android:style/Widget.Holo.Light.Spinner.DropDown.ActionBar">
         "android:background">@drawable/ad_spinner_background_holo_light
         "android:popupBackground">@drawable/ad_menu_dropdown_panel_holo_light
         "android:dropDownSelector">@drawable/ad_selectable_background

      把style设置好后，只需在AndroidManifest.xml中application或activity的位置加上

      细心的读者可能会发现，其实以前android的属性拿过来都能用，比如说修改actionbar的高度，，只需把这些属性放在对应的位置，作为一个存在即可。

4、res/drawable下的一些xml文件，即actionbar修改所需的资源。

4、1------actionbar_tab_bg.xml，用于tab的背景修改。曾一度认为只需在系统tab的基础上修改一下颜色即可，其实不然。需另外弄几张图片，（如我想把tab改成红色背景，那么我就要找几张红色背景的图片）。

 "1.0" encoding="utf-8"?>
 "http://schemas.android.com/apk/res/android">

     "false" android:state_selected="false" android:state_pressed="false" android:drawable="@drawable/ad_tab_unselected_holo" />
     "false" android:state_selected="true"  android:state_pressed="false" android:drawable="@drawable/ad_tab_selected_holo" />
     "false" android:state_pressed="true" android:drawable="@drawable/ad_tab_selected_pressed_holo" />
     "true"  android:state_pressed="true" android:drawable="@drawable/ad_tab_selected_pressed_holo" />

4、2------ad_action_bar_gradient_bak.xml，用于actionbar的颜色渐变，本例是从顶到底颜色逐渐变浅。

 "1.0" encoding="utf-8"?>
 "http://schemas.android.com/apk/res/android" android:shape="rectangle">

         android:startColor="@color/honeycombish_blue"
         android:endColor="@color/background"
         android:type="linear"
         android:angle="270" />

4、3------ad_btn_check_holo_light.xml，用于单选背景的变换。

 "1.0" encoding="utf-8"?>
 "http://schemas.android.com/apk/res/android">


     "true" android:state_window_focused="false"
         android:state_enabled="true" android:drawable="@drawable/btn_check_on_holo_light" />

     "false" android:state_window_focused="false"
         android:state_enabled="true" android:drawable="@drawable/btn_check_off_holo_light" />

     "true" android:state_pressed="true"
         android:state_enabled="true" android:drawable="@drawable/ad_btn_check_on_pressed_holo_light" />

     "false" android:state_pressed="true"
         android:state_enabled="true" android:drawable="@drawable/ad_btn_check_off_pressed_holo_light" />



     "false" android:state_enabled="true"
         android:drawable="@drawable/btn_check_off_holo_light" />

     "true" android:state_enabled="true"
         android:drawable="@drawable/btn_check_on_holo_light" />

4、4------ad_btn_radio_holo_light.xml，用于多选背景的变换。

 "1.0" encoding="utf-8"?>
 "http://schemas.android.com/apk/res/android">


     "true" android:state_window_focused="false"
         android:state_enabled="true" android:drawable="@drawable/btn_radio_on_holo_light" />

     "false" android:state_window_focused="false"
         android:state_enabled="true" android:drawable="@drawable/btn_radio_off_holo_light" />

     "true" android:state_pressed="true"
         android:state_enabled="true" android:drawable="@drawable/ad_btn_radio_on_pressed_holo_light" />

     "false" android:state_pressed="true"
         android:state_enabled="true" android:drawable="@drawable/ad_btn_radio_off_pressed_holo_light" />



     "false" android:state_enabled="true"
         android:drawable="@drawable/btn_radio_off_holo_light" />

     "true" android:state_enabled="true"
         android:drawable="@drawable/btn_radio_on_holo_light" />

4、5------ad_btn_radio_holo_light.xml，用于item背景的变换，未选中时为透明，选中未绿色。

 "1.0" encoding="utf-8"?>
 "http://schemas.android.com/apk/res/android"
           android:exitFadeDuration="@android:integer/config_mediumAnimTime" >
     "true" android:drawable="@drawable/selected_background" />
     "@android:color/transparent" />

4、6------ad_spinner_background_holo_light.xml，用于下拉列表背景的变换。

 "1.0" encoding="utf-8"?>
 "http://schemas.android.com/apk/res/android">
     "false"
           android:drawable="@drawable/spinner_disabled_holo_light" />
     "true"
           android:drawable="@drawable/ad_spinner_pressed_holo_light" />
     "false" android:state_focused="true"
           android:drawable="@drawable/ad_spinner_focused_holo_light" />
     "@drawable/spinner_default_holo_light" />

4、7------rounded_rect.xml，用于本例RoundedColourFragment视图的设置。

 "1.0" encoding="utf-8"?>
 "http://schemas.android.com/apk/res/android" android:shape="rectangle">
     "@dimen/frag_rounding_radius" />

dimens.xml

 "1.0" encoding="utf-8"?>

     "frag_rounding_radius">20dp
     "progress_action_padding">8dp