Android利用DrawerLayout实现抽屉效果

    <android.support.v4.widget.DrawerLayout  
        xmlns:android="http://schemas.android.com/apk/res/android"  
        android:id="@+id/drawer_layout"  
        android:layout_width="match_parent"  
        android:layout_height="match_parent">  
      
        <FrameLayout  
            android:id="@+id/content_frame"  
            android:layout_width="match_parent"  
            android:layout_height="match_parent" />  
      
        <ListView  
            android:id="@+id/left_drawer"  
            android:layout_width="240dp"  
            android:layout_height="match_parent"  
            android:layout_gravity="right"  
            android:choiceMode="singleChoice"  
            android:divider="@android:color/transparent"  
            android:dividerHeight="0dp"  
            android:background="#111"/>  
        <!--   
            android:choiceMode  选中状态 跟itemclick没有冲突  
                    none              值为0，表示无选择模式；   
                    singleChoice      值为1，表示最多可以有一项被选中；  
                    multipleChoice    值为2，表示可以多项被选中。  
                      
            android:layout_gravity  left或right  left或start   right或end  
                表示在抽屉里的效果是从左到右还是从右到左出现  
         -->  
    </android.support.v4.widget.DrawerLayout>  

    package com.stone.drawerlayout;  
    /* 
     * Copyright 2013 The Android Open Source Project 
     * 
     * Licensed under the Apache License,Version 2.0 (the "License"); 
     * you may not use this file except in compliance with the License. 
     * You may obtain a copy of the License at 
     * 
     *     http://www.apache.org/licenses/LICENSE-2.0 
     * 
     * Unless required by applicable law or agreed to in writing,software 
     * distributed under the License is distributed on an "AS IS" BASIS,* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,either express or implied. 
     * See the License for the specific language governing permissions and 
     * limitations under the License. 
     */  
      
    import java.util.Locale;  
      
    import android.app.Activity;  
    import android.app.Fragment;  
    import android.app.FragmentManager;  
    import android.app.SearchManager;  
    import android.content.Intent;  
    import android.content.res.Configuration;  
    import android.os.Bundle;  
    import android.support.v4.app.ActionBarDrawerToggle;  
    import android.support.v4.view.GravityCompat;  
    import android.support.v4.widget.DrawerLayout;  
    import android.view.LayoutInflater;  
    import android.view.Menu;  
    import android.view.MenuInflater;  
    import android.view.MenuItem;  
    import android.view.View;  
    import android.view.ViewGroup;  
    import android.widget.AdapterView;  
    import android.widget.ArrayAdapter;  
    import android.widget.ImageView;  
    import android.widget.ListView;  
    import android.widget.Toast;  
      
    /** 
     * This example illustrates a common usage of the DrawerLayout widget 
     * in the Android support library. 
     * <p/> 
     * <p>When a navigation (left) drawer is present,the host activity should detect presses of 
     * the action bar's Up affordance as a signal to open and close the navigation drawer. The 
     * ActionBarDrawerToggle facilitates this behavior. 
     * Items within the drawer should fall into one of two categories:</p> 
     * <p/> 
     * <ul> 
     * <li><strong>View switches</strong>. A view switch follows the same basic policies as 
     * list or tab navigation in that a view switch does not create navigation history. 
     * This pattern should only be used at the root activity of a task,leaving some form 
     * of Up navigation active for activities further down the navigation hierarchy.</li> 
     * <li><strong>Selective Up</strong>. The drawer allows the user to choose an alternate 
     * parent for Up navigation. This allows a user to jump across an app's navigation 
     * hierarchy at will. The application should treat this as it treats Up navigation from 
     * a different task,replacing the current task stack using TaskStackBuilder or similar. 
     * This is the only form of navigation drawer that should be used outside of the root 
     * activity of a task.</li> 
     * </ul> 
     * <p/> 
     * <p>Right side drawers should be used for actions,not navigation. This follows the pattern 
     * established by the Action Bar that navigation should be to the left and actions to the right. 
     * An action should be an operation performed on the current contents of the window,* for example enabling or disabling a data overlay on top of the current content.</p> 
     */  
    public class MainActivity extends Activity {  
        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);//抽屉里的view  
      
            // set a custom shadow that overlays the main content when the drawer opens  
            mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow,GravityCompat.START);//设置shadow  
            // 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   需要api level 11  
            getActionBar().setDisplayHomeAsUpEnabled(true);//给home icon的左边加上一个返回的图标  
            getActionBar().setHomeButtonEnabled(true); //需要api level 14  使用home-icon 可点击  
      
            // ActionBarDrawerToggle ties together the the proper interactions  
            // between the sliding drawer and the action bar app icon  
            mDrawerToggle = new ActionBarDrawerToggle(//v4控件  actionbar上的抽屉开关  
                    this,/* host Activity */  
                    mDrawerLayout,/* DrawerLayout object */  
                    R.drawable.ic_drawer,/* nav drawer image to replace 'Up' caret */     //上一级图标 返回图标  
                    R.string.drawer_open,/* "open drawer" description for accessibility */  
                    R.string.drawer_close  /* "close drawer" description for accessibility */  
                    ) {  
                public void onDrawerClosed(View view) {//抽屉关闭后  
                    getActionBar().setTitle(mDrawerTitle);  
                    invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()  
                }  
      
                public void onDrawerOpened(View drawerView) {//抽屉打开后  
                    getActionBar().setTitle(mTitle);  
                    invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()  
                }  
                  
                @Override  
                public boolean onOptionsItemSelected(MenuItem item) {  
                    if (item != null && item.getItemId() == android.R.id.home) {//actionbar上的home icon  
                        //END即gravity.right 从右向左显示   START即left  从左向右弹出显示  
                        if (mDrawerLayout.isDrawerVisible(GravityCompat.END)) {  
                            mDrawerLayout.closeDrawer(GravityCompat.END);//关闭抽屉  
                        } else {  
                            mDrawerLayout.openDrawer(GravityCompat.END);//打开抽屉  
                        }  
                        return true;  
                    }  
                    return false;  
                }  
            };  
            mDrawerLayout.setDrawerListener(mDrawerToggle);//设置抽屉监听  
      
            if (savedInstanceState == null) {  
    //            selectItem(0);  
            }  
        }  
      
        @Override  
        public boolean onCreateOptionsMenu(Menu menu) {//加载menu  sdk3.0以后menu包含在actionbar中  
            MenuInflater inflater = getMenuInflater();  
            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);//search的显示与drawer的显示相反  
            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 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,getActionBar().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);  
            }  
        }  
      
        /* 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);  
            }  
        }  
          
      //内容区显示PlanetFragment  
        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 = getFragmentManager();  
            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) {  
            mDrawerTitle = title;  
            getActionBar().setTitle(mDrawerTitle);  
        }  
      
        /** 
         * 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];  
                //查找出 res-drawable资源的id  
                int imageId = getResources().getIdentifier(planet.toLowerCase(Locale.getDefault()),"drawable",getActivity().getPackageName());  
                ((ImageView) rootView.findViewById(R.id.image)).setImageResource(imageId);  
                getActivity().setTitle(planet);  
                return rootView;  
            }  
        }  
    }