Android 抽屉效果的导航菜单实现

抽屉效果的导航菜单

　　看了很多应用，觉得这种侧滑的抽屉效果的菜单很好。

　　不用切换到另一个页面，也不用去按菜单的硬件按钮，直接在界面上一个按钮点击，菜单就滑出来，而且感觉能放很多东西。

　　关于实现，搜索了一下，有如下两种：

　　1.用SlidingDrawer：

　　http://developer.android.com/reference/android/widget/SlidingDrawer.html

　　但是不知道为什么这个类官方不建议再继续用了：

　　Deprecated since API level 17

　　2.用DrawerLayout：

　　http://developer.android.com/reference/android/support/v4/widget/DrawerLayout.html

　　Guide在这里：

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

库的引用

　　首先， DrawerLayout这个类是在Support Library里的，需要加上android-support-v4.jar这个包。

　　然后程序中用时在前面导入import android.support.v4.widget.DrawerLayout;

　　如果找不到这个类，首先用SDK Manager更新一下Android Support Library，然后在Android SDK\extras\android\support\v4路径下找到android-support-v4.jar，复制到项目的libs路径，将其Add to Build Path.

代码1

　　布局：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent" >

    <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" >

        <!-- The main content view -->

        <!-- main content must be the first element of DrawerLayout because it will be drawn first and drawer must be on top of it -->

        <FrameLayout

            android:id="@+id/content_frame"

            android:layout_width="match_parent"

            android:layout_height="match_parent" />

        <!-- The navigation drawer -->

        <ListView

            android:id="@+id/left_drawer"

            android:layout_width="240dp"

            android:layout_height="match_parent"

            android:layout_gravity="left"

            android:background="#111"

            android:choiceMode="singleChoice"

            android:divider="@android:color/transparent"

            android:dividerHeight="0dp" />

    </android.support.v4.widget.DrawerLayout>

</RelativeLayout>

　　DrawerLayout的第一个子元素是主要内容，即抽屉没有打开时显示的布局。这里采用了一个FrameLayout，里面什么也没放。

　　DrawerLayout的第二个子元素是抽屉中的内容，即抽屉布局，这里采用了一个ListView。

　　主要的Activity（从官方实例中扒出来的）：

package com.example.hellodrawer;

import android.os.Bundle;

import android.app.Activity;

import android.content.res.Configuration;

import android.view.MenuItem;

import android.view.View;

import android.widget.AdapterView;

import android.widget.AdapterView.OnItemClickListener;

import android.widget.ArrayAdapter;

import android.widget.ListView;

import android.support.v4.app.ActionBarDrawerToggle;

import android.support.v4.view.GravityCompat;

import android.support.v4.widget.DrawerLayout;

public class HelloDrawerActivity extends Activity

{

    private String[] mPlanetTitles;

    private DrawerLayout mDrawerLayout;

    private ActionBarDrawerToggle mDrawerToggle;

    private ListView mDrawerList;

    @Override

    public void onCreate(Bundle savedInstanceState)

    {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_hello_drawer);

        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);

        // init the ListView and Adapter, nothing new

        initListView();

        // set a custom shadow that overlays the main content when the drawer

        // opens

        mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow,

                GravityCompat.START);

        mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout,

                R.drawable.ic_drawer, R.string.drawer_open,

                R.string.drawer_close)

        {

            /** Called when a drawer has settled in a completely closed state. */

            public void onDrawerClosed(View view)

            {

                invalidateOptionsMenu(); // creates call to

                                            // onPrepareOptionsMenu()

            }

            /** Called when a drawer has settled in a completely open state. */

            public void onDrawerOpened(View drawerView)

            {

                invalidateOptionsMenu(); // creates call to

                                            // onPrepareOptionsMenu()

            }

        };

        // Set the drawer toggle as the DrawerListener

        mDrawerLayout.setDrawerListener(mDrawerToggle);

        // enable ActionBar app icon to behave as action to toggle nav drawer

        getActionBar().setDisplayHomeAsUpEnabled(true);

        // getActionBar().setHomeButtonEnabled(true);

        // Note: getActionBar() Added in API level 11

    }

    private void initListView()

    {

        mDrawerList = (ListView) findViewById(R.id.left_drawer);

        mPlanetTitles = getResources().getStringArray(R.array.planets_array);

        // Set the adapter for the list view

        mDrawerList.setAdapter(new ArrayAdapter<String>(this,

                R.layout.list_item, mPlanetTitles));

        // Set the list's click listener

        mDrawerList.setOnItemClickListener(new OnItemClickListener()

        {

            @Override

            public void onItemClick(AdapterView<?> parent, View view,

                    int position, long id)

            {

                // Highlight the selected item, update the title, and close the

                // drawer

                mDrawerList.setItemChecked(position, true);

                setTitle(mPlanetTitles[position]);

                mDrawerLayout.closeDrawer(mDrawerList);

            }

        });

    }

    @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);

        mDrawerToggle.onConfigurationChanged(newConfig);

    }

    @Override

    public boolean onOptionsItemSelected(MenuItem item)

    {

        // Pass the event to ActionBarDrawerToggle, if it returns

        // true, then it has handled the app icon touch event

        if (mDrawerToggle.onOptionsItemSelected(item))

        {

            return true;

        }

        // Handle your other action bar items...

        return super.onOptionsItemSelected(item);

    }

}

　　比较纠结的是用了Level 11的一个API，这样minSdkVersion就有限制，不能太低。

　　图片资源Android官网示例处提供下载了。

　　程序运行后效果如下：

　　抽屉打开前：

　　抽屉打开后：

代码2

　　今天又看了一下DrawerLayout的类，发现有很多方法可以直接用的。

　　重新试了一下，其实不用上面那么麻烦，随便自己定义一个按钮控制抽屉的打开就行：

　　布局：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:paddingBottom="@dimen/activity_vertical_margin"

    android:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    tools:context=".DrawerActivity" >

    <android.support.v4.widget.DrawerLayout

        android:id="@+id/drawer_layout"

        android:layout_width="match_parent"

        android:layout_height="match_parent" >

        <!-- The main content view -->

        <FrameLayout

            android:id="@+id/content_frame"

            android:layout_width="match_parent"

            android:layout_height="match_parent" >

            <Button

                android:id="@+id/btn"

                android:layout_width="match_parent"

                android:layout_height="wrap_content"

                android:text="open"

                />

        </FrameLayout>

        <!-- The navigation drawer -->

        <ListView

            android:id="@+id/left_drawer"

            android:layout_width="240dp"

            android:layout_height="match_parent"

            android:layout_gravity="start"

            android:background="#111"

            android:choiceMode="singleChoice"

            android:divider="@android:color/transparent"

            android:dividerHeight="0dp" />

    </android.support.v4.widget.DrawerLayout>

</RelativeLayout>

　　主要代码：

package com.example.hellodrawer;

import android.os.Bundle;

import android.app.Activity;

import android.support.v4.widget.DrawerLayout;

import android.view.Gravity;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

public class DrawerActivity extends Activity

{

    private DrawerLayout mDrawerLayout = null;

    @Override

    protected void onCreate(Bundle savedInstanceState)

    {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_drawer);

        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);

        Button button = (Button) findViewById(R.id.btn);

        button.setOnClickListener(new OnClickListener()

        {

            @Override

            public void onClick(View v)

            {

                // 按钮按下，将抽屉打开

                mDrawerLayout.openDrawer(Gravity.LEFT);

            }

        });

    }

}

参考资料

　　官方教程：

　　http://developer.android.com/design/patterns/navigation-drawer.html

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

　　其他参考资料：

　　http://blog.chengyunfeng.com/?p=493

　　http://my.eoe.cn/appadventure/archive/3826.html