Android UI开发第三十三篇——Navigation Drawer For Android API 7

Creating a Navigation Drawer中使用的Navigation Drawer的android:minSdkVersion="14"，现在Android API Version 小于14的还有30%左右呢。Android个版本的占有量可参考 Platform Version。

Android Platform Version

我们的应用为了适配不同的版本，需要降低minSdkVersion，作者一般适配SDK到API 7。这一篇博文也是把Creating a Navigation Drawer的例子适配到API 7 。例子中降低API最主要的修改Action Bar，Action Bar是API 11才出现的，适配到API 7，我们使用了actionbarsherlock.

修改后的代码：

public class MainActivity extends SherlockFragmentActivity {
    private DrawerLayout mDrawerLayout;
    private ListView mDrawerList;
    private ActionBarDrawerToggle mDrawerToggle;

    private CharSequence mDrawerTitle;
    private CharSequence mTitle;
    private String[] mPlanetTitles;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        mTitle = mDrawerTitle = getTitle();
        mPlanetTitles = getResources().getStringArray(R.array.planets_array);
        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        mDrawerList = (ListView) findViewById(R.id.left_drawer);

        // set a custom shadow that overlays the main content when the drawer opens
        mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START);
        // set up the drawer's list view with items and click listener
        mDrawerList.setAdapter(new ArrayAdapter<String>(this,
                R.layout.drawer_list_item, mPlanetTitles));
        mDrawerList.setOnItemClickListener(new DrawerItemClickListener());

        // enable ActionBar app icon to behave as action to toggle nav drawer
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        getSupportActionBar().setHomeButtonEnabled(true);

        // ActionBarDrawerToggle ties together the the proper interactions
        // between the sliding drawer and the action bar app icon
        mDrawerToggle = new ActionBarDrawerToggle(
                this,                  /* host Activity */
                mDrawerLayout,         /* DrawerLayout object */
                R.drawable.ic_drawer,  /* nav drawer image to replace 'Up' caret */
                R.string.drawer_open,  /* "open drawer" description for accessibility */
                R.string.drawer_close  /* "close drawer" description for accessibility */
                ) {

        	/** Called when a drawer has settled in a completely closed state. */
            public void onDrawerClosed(View view) {
            	getSupportActionBar().setTitle(mTitle);
            }  

            /** Called when a drawer has settled in a completely open state. */
            public void onDrawerOpened(View drawerView) {
            	getSupportActionBar().setTitle(mDrawerTitle);
            }  

        };
        mDrawerLayout.setDrawerListener(mDrawerToggle);

        if (savedInstanceState == null) {
            selectItem(0);
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getSupportMenuInflater();
        inflater.inflate(R.menu.main, menu);
        return super.onCreateOptionsMenu(menu);
    }

    /* Called whenever we call invalidateOptionsMenu() */
    @Override
    public boolean onPrepareOptionsMenu(Menu menu) {
        // If the nav drawer is open, hide action items related to the content view
        boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
        menu.findItem(R.id.action_websearch).setVisible(!drawerOpen);
        return super.onPrepareOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
         // The action bar home/up action should open or close the drawer.
         // ActionBarDrawerToggle will take care of this.
//        if (mDrawerToggle.onOptionsItemSelected(item)) {
//            return true;
//        }
        // Handle action buttons
        switch(item.getItemId()) {
        case android.R.id.home:
        	handleNavigationDrawerToggle();
        	return true;
        case R.id.action_websearch:
            // create intent to perform web search for this planet
            Intent intent = new Intent(Intent.ACTION_WEB_SEARCH);
            intent.putExtra(SearchManager.QUERY, getSupportActionBar().getTitle());
            // catch event that there's no activity to handle intent
            if (intent.resolveActivity(getPackageManager()) != null) {
                startActivity(intent);
            } else {
                Toast.makeText(this, R.string.app_not_available, Toast.LENGTH_LONG).show();
            }
            return true;
        default:
            return super.onOptionsItemSelected(item);
        }
    }
    private void handleNavigationDrawerToggle() {
        if (mDrawerLayout.isDrawerOpen(mDrawerList)) {
        	mDrawerLayout.closeDrawer(mDrawerList);
        } else {
        	mDrawerLayout.openDrawer(mDrawerList);
        }
      }
    /* The click listner for ListView in the navigation drawer */
    private class DrawerItemClickListener implements ListView.OnItemClickListener {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            selectItem(position);
        }
    }

    private void selectItem(int position) {
        // update the main content by replacing fragments
        Fragment fragment = new PlanetFragment();
        Bundle args = new Bundle();
        args.putInt(PlanetFragment.ARG_PLANET_NUMBER, position);
        fragment.setArguments(args);

        FragmentManager fragmentManager = getSupportFragmentManager();
        fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit();

        // update selected item and title, then close the drawer
        mDrawerList.setItemChecked(position, true);
        setTitle(mPlanetTitles[position]);
        mDrawerLayout.closeDrawer(mDrawerList);
    }

    @Override
    public void setTitle(CharSequence title) {
        mTitle = title;
        getSupportActionBar().setTitle(mTitle);
    }

    /**
     * When using the ActionBarDrawerToggle, you must call it during
     * onPostCreate() and onConfigurationChanged()...
     */

    @Override
    protected void onPostCreate(Bundle savedInstanceState) {
        super.onPostCreate(savedInstanceState);
        // Sync the toggle state after onRestoreInstanceState has occurred.
        mDrawerToggle.syncState();
    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        // Pass any configuration change to the drawer toggls
        mDrawerToggle.onConfigurationChanged(newConfig);
    }

    /**
     * Fragment that appears in the "content_frame", shows a planet
     */
    public static class PlanetFragment extends Fragment {
        public static final String ARG_PLANET_NUMBER = "planet_number";

        public PlanetFragment() {
            // Empty constructor required for fragment subclasses
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_planet, container, false);
            int i = getArguments().getInt(ARG_PLANET_NUMBER);
            String planet = getResources().getStringArray(R.array.planets_array)[i];

            int imageId = getResources().getIdentifier(planet.toLowerCase(Locale.getDefault()),
                            "drawable", getActivity().getPackageName());
            ((ImageView) rootView.findViewById(R.id.image)).setImageResource(imageId);
            getActivity().setTitle(planet);
            return rootView;
        }
    }
}

如果只修改JAVA代码，运行应用还是会出现异常：

08-13 13:26:15.909: E/AndroidRuntime(6832): FATAL EXCEPTION: main
08-13 13:26:15.909: E/AndroidRuntime(6832): android.view.InflateException: Binary XML file line #2: Error inflating class <unknown>
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.view.LayoutInflater.createView(LayoutInflater.java:518)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:56)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:568)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.view.LayoutInflater.inflate(LayoutInflater.java:386)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.view.LayoutInflater.inflate(LayoutInflater.java:320)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:332)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.widget.ArrayAdapter.getView(ArrayAdapter.java:323)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.widget.AbsListView.obtainView(AbsListView.java:1495)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.widget.ListView.measureHeightOfChildren(ListView.java:1216)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.widget.ListView.onMeasure(ListView.java:1127)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.view.View.measure(View.java:8335)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.widget.RelativeLayout.measureChild(RelativeLayout.java:566)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:381)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.view.View.measure(View.java:8335)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.widget.FrameLayout.onMeasure(FrameLayout.java:250)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.view.View.measure(View.java:8335)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.widget.LinearLayout.measureVertical(LinearLayout.java:531)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.widget.LinearLayout.onMeasure(LinearLayout.java:309)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.view.View.measure(View.java:8335)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.widget.FrameLayout.onMeasure(FrameLayout.java:250)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.view.View.measure(View.java:8335)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.view.ViewRoot.performTraversals(ViewRoot.java:843)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.view.ViewRoot.handleMessage(ViewRoot.java:1892)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.os.Handler.dispatchMessage(Handler.java:99)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.os.Looper.loop(Looper.java:130)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.app.ActivityThread.main(ActivityThread.java:3835)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at java.lang.reflect.Method.invokeNative(Native Method)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at java.lang.reflect.Method.invoke(Method.java:507)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:864)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:622)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at dalvik.system.NativeStart.main(Native Method)
08-13 13:26:15.909: E/AndroidRuntime(6832): Caused by: java.lang.reflect.InvocationTargetException
08-13 13:26:15.909: E/AndroidRuntime(6832):     at java.lang.reflect.Constructor.constructNative(Native Method)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at java.lang.reflect.Constructor.newInstance(Constructor.java:415)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.view.LayoutInflater.createView(LayoutInflater.java:505)
08-13 13:26:15.909: E/AndroidRuntime(6832):     ... 32 more
08-13 13:26:15.909: E/AndroidRuntime(6832): Caused by: java.lang.UnsupportedOperationException: Can't convert to dimension: type=0x2
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.content.res.TypedArray.getDimensionPixelSize(TypedArray.java:463)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.view.View.<init>(View.java:1978)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.widget.TextView.<init>(TextView.java:350)
08-13 13:26:15.909: E/AndroidRuntime(6832):     at android.widget.TextView.<init>(TextView.java:343)
08-13 13:26:15.909: E/AndroidRuntime(6832):     ... 35 more

这个异常是
drawer_list_item.xml文件的内容产生的，drawer_list_item.xml内容：

<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@android:id/text1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceListItemSmall"
    android:gravity="center_vertical"
    android:paddingLeft="16dp"
    android:paddingRight="16dp"
    android:textColor="#fff"
    android:background="?android:attr/activatedBackgroundIndicator"
    android:minHeight="?android:attr/listPreferredItemHeightSmall"/>

而在API 14之前的版本中，下面的三个属性会报异常：

<TextView xmlns:android="http://schemas.android.com/apk/res/android"
      android:textAppearance="?android:attr/textAppearanceListItemSmall"
      android:background="?android:attr/activatedBackgroundIndicator"
      android:minHeight="?android:attr/listPreferredItemHeightSmall"/>

如果想适配更低的版本需要做如下的修改：

1）修改drawer_list_item.xml文件，使用自定义的属性

<?xml version="1.0" encoding="UTF-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@android:id/text1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="?attr/myapp_activatedBackgroundIndicator"
    android:gravity="center_vertical"
    android:minHeight="?attr/myapp_listPreferredItemHeightSmall"
    android:paddingLeft="16dp"
    android:paddingRight="16dp"
    android:textAppearance="?attr/myapp_textAppearanceListItemSmall" />

2）在
values/attrs.xml文件中声明自定义属性

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="AppTheme">

    <!-- Attributes below are needed to support the navigation drawer on Android 3.x. -->
    <!-- A smaller, sleeker list item height. -->
    <attr name="myapp_listPreferredItemHeightSmall" format="dimension" />

    <!-- Drawable used as a background for activated items. -->
    <attr name="myapp_activatedBackgroundIndicator" format="reference" />

    <!-- The preferred TextAppearance for the primary text of small list items. -->
    <attr name="myapp_textAppearanceListItemSmall" format="reference" />
</declare-styleable>
</resources>

3）
在values-11/styles.xml文件中添加

  <!--
        Base application theme, dependent on API level. This theme is replaced
        by AppBaseTheme from res/values-vXX/styles.xml on newer devices.
    -->
    <style name="AppBaseTheme" parent="Theme.Sherlock.Light.DarkActionBar">

        <!--
            Theme customizations available in newer API levels can go in
            res/values-vXX/styles.xml, while customizations related to
            backward-compatibility can go here.
        -->
        <!-- Implementation of attributes needed for the navigation drawer as the default implementation is based on API-14. -->
        <item name="myapp_listPreferredItemHeightSmall">48dip</item>
        <item name="myapp_textAppearanceListItemSmall">@style/MyappDrawerMenu</item>
        <item name="myapp_activatedBackgroundIndicator">@android:color/transparent</item>
    </style>

    <style name="MyappDrawerMenu">
        <item name="android:textSize">16sp</item>
        <item name="android:textStyle">bold</item>
        <item name="android:textColor">@android:color/black</item>
    </style>

4）
在values-v14/styles.xml文件中添加

<!--
        Base application theme for API 14+. This theme completely replaces
        AppBaseTheme from BOTH res/values/styles.xml and
        res/values-v11/styles.xml on API 14+ devices.
    -->
    <style name="AppBaseTheme" parent="android:Theme.Holo.Light.DarkActionBar">
         <!-- For API-14 and above the default implementation of the navigation drawer menu is used. Below APU-14 a custom implementation is used. -->
           <item name="myapp_listPreferredItemHeightSmall">?android:attr/listPreferredItemHeightSmall</item>
           <item name="myapp_textAppearanceListItemSmall">?android:attr/textAppearanceListItemSmall</item>
           <item name="myapp_activatedBackgroundIndicator">?android:attr/activatedBackgroundIndicator</item>
       </style>

OK，经过上面步骤，运行成功，这样上一篇的例子就能很好的适配到API 7了。

         

/**

* @author 张兴业

*  http://blog.csdn.net/xyz_lmn

*  iOS入门群：83702688

*  android开发进阶群：241395671

*  我的新浪微博：@张兴业TBOW

*/

代码下载：Demo