Android利用DrawerLayout实现抽屉效果详解编程语言

官网guide：http://developer.android.com/training/implementing-navigation/nav-drawer.html

官网示例：NavigationDrawer.zip  

android.support.v4.widget.DrawerLayout 抽屉layout。该widget只能实现从左向右、从右向左

   openDrawer(), closeDrawer(), isDrawerOpen()

下面贴一下示例的主要的布局文件 和 activity实现

activity_main.xml

    <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;   
}   
}   
}