ViewPager和FragmentPagerAdapter

该代码来源于 慕课 网 学习视频：
MainActivity.class

package com.imooc.tab03;

import java.util.ArrayList;
import java.util.List;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.widget.ImageButton;
import android.widget.LinearLayout;

public class MainActivity extends FragmentActivity implements OnClickListener
{
    private ViewPager mViewPager;
    private FragmentPagerAdapter mAdapter;
    private List<Fragment> mFragments;

    private LinearLayout mTabWeixin;
    private LinearLayout mTabFrd;
    private LinearLayout mTabAddress;
    private LinearLayout mTabSettings;

    private ImageButton mImgWeixin;
    private ImageButton mImgFrd;
    private ImageButton mImgAddress;
    private ImageButton mImgSettings;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_main);

        initView();
        initEvent();

        setSelect(1);
    }

    private void initEvent()
    {
        mTabWeixin.setOnClickListener(this);
        mTabFrd.setOnClickListener(this);
        mTabAddress.setOnClickListener(this);
        mTabSettings.setOnClickListener(this);
    }

    private void initView()
    {
        mViewPager = (ViewPager) findViewById(R.id.id_viewpager);

        mTabWeixin = (LinearLayout) findViewById(R.id.id_tab_weixin);
        mTabFrd = (LinearLayout) findViewById(R.id.id_tab_frd);
        mTabAddress = (LinearLayout) findViewById(R.id.id_tab_address);
        mTabSettings = (LinearLayout) findViewById(R.id.id_tab_settings);

        mImgWeixin = (ImageButton) findViewById(R.id.id_tab_weixin_img);
        mImgFrd = (ImageButton) findViewById(R.id.id_tab_frd_img);
        mImgAddress = (ImageButton) findViewById(R.id.id_tab_address_img);
        mImgSettings = (ImageButton) findViewById(R.id.id_tab_settings_img);

        mFragments = new ArrayList<Fragment>();
        Fragment mTab01 = new WeixinFragment();
        Fragment mTab02 = new FrdFragment();
        Fragment mTab03 = new AddressFragment();
        Fragment mTab04 = new SettingFragment();
        mFragments.add(mTab01);
        mFragments.add(mTab02);
        mFragments.add(mTab03);
        mFragments.add(mTab04);

        mAdapter = new FragmentPagerAdapter(getSupportFragmentManager())
        {

            @Override
            public int getCount()
            {
                return mFragments.size();
            }

            @Override
            public Fragment getItem(int arg0)
            {
                return mFragments.get(arg0);
            }
        };
        mViewPager.setAdapter(mAdapter);

        mViewPager.setOnPageChangeListener(new OnPageChangeListener()
        {

            @Override
            public void onPageSelected(int arg0)
            {
                int currentItem = mViewPager.getCurrentItem();
                setTab(currentItem);
            }

            @Override
            public void onPageScrolled(int arg0, float arg1, int arg2)
            {
                // TODO Auto-generated method stub

            }

            @Override
            public void onPageScrollStateChanged(int arg0)
            {
                // TODO Auto-generated method stub

            }
        });
    }

    @Override
    public void onClick(View v)
    {
        switch (v.getId())
        {
        case R.id.id_tab_weixin:
            setSelect(0);
            break;
        case R.id.id_tab_frd:
            setSelect(1);
            break;
        case R.id.id_tab_address:
            setSelect(2);
            break;
        case R.id.id_tab_settings:
            setSelect(3);
            break;

        default:
            break;
        }
    }

    private void setSelect(int i)
    {
        setTab(i);
        mViewPager.setCurrentItem(i);
    }

    private void setTab(int i)
    {
        resetImgs();
        // 设置图片为亮色
        // 切换内容区域
        switch (i)
        {
        case 0:
            mImgWeixin.setImageResource(R.drawable.tab_weixin_pressed);
            break;
        case 1:
            mImgFrd.setImageResource(R.drawable.tab_find_frd_pressed);
            break;
        case 2:
            mImgAddress.setImageResource(R.drawable.tab_address_pressed);
            break;
        case 3:
            mImgSettings.setImageResource(R.drawable.tab_settings_pressed);
            break;
        }
    }

    /**
     * 切换图片至暗色
     */
    private void resetImgs()
    {
        mImgWeixin.setImageResource(R.drawable.tab_weixin_normal);
        mImgFrd.setImageResource(R.drawable.tab_find_frd_normal);
        mImgAddress.setImageResource(R.drawable.tab_address_normal);
        mImgSettings.setImageResource(R.drawable.tab_settings_normal);
    }

}

activity_main.xml

<LinearLayout 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:orientation="vertical" >

    <include layout="@layout/top" />

    <android.support.v4.view.ViewPager
        android:id="@+id/id_viewpager"
        android:layout_width="fill_parent"
        android:layout_height="0dp"
        android:layout_weight="1" >
    </android.support.v4.view.ViewPager>

    <include layout="@layout/bottom" />

</LinearLayout>

top.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="45dp"
    android:background="@drawable/title_bar"
    android:gravity="center"
    android:orientation="vertical" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:text="微信"
        android:textColor="#ffffff"
        android:textSize="20sp"
        android:textStyle="bold" />

</LinearLayout>

buttom.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="55dp"
    android:background="@drawable/bottom_bar"
    android:orientation="horizontal" >

    <LinearLayout
        android:id="@+id/id_tab_weixin"
        android:layout_width="0dp"
        android:layout_height="fill_parent"
        android:layout_weight="1"
        android:gravity="center"
        android:orientation="vertical" >

        <ImageButton
            android:id="@+id/id_tab_weixin_img"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="#00000000"
            android:clickable="false"
            android:src="@drawable/tab_weixin_pressed" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="微信"
            android:textColor="#ffffff" />
    </LinearLayout>

    <LinearLayout
        android:id="@+id/id_tab_frd"
        android:layout_width="0dp"
        android:layout_height="fill_parent"
        android:layout_weight="1"
        android:gravity="center"
        android:orientation="vertical" >

        <ImageButton
            android:id="@+id/id_tab_frd_img"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="#00000000"
            android:clickable="false"
            android:src="@drawable/tab_find_frd_normal" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="朋友"
            android:textColor="#ffffff" />
    </LinearLayout>

    <LinearLayout
        android:id="@+id/id_tab_address"
        android:layout_width="0dp"
        android:layout_height="fill_parent"
        android:layout_weight="1"
        android:gravity="center"
        android:orientation="vertical" >

        <ImageButton
            android:id="@+id/id_tab_address_img"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="#00000000"
            android:clickable="false"
            android:src="@drawable/tab_address_normal" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="通讯录"
            android:textColor="#ffffff" />
    </LinearLayout>

    <LinearLayout
        android:id="@+id/id_tab_settings"
        android:layout_width="0dp"
        android:layout_height="fill_parent"
        android:layout_weight="1"
        android:gravity="center"
        android:orientation="vertical" >

        <ImageButton
            android:id="@+id/id_tab_settings_img"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="#00000000"
            android:clickable="false"
            android:src="@drawable/tab_settings_normal" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="设置"
            android:textColor="#ffffff" />
    </LinearLayout>

</LinearLayout>

四个相同的Fragment:::
WeixinFragment
new FrdFragment
AddressFragment
SettingFragment

public class AddressFragment extends Fragment
{
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState)
    {
        return inflater.inflate(R.layout.tab03, container, false);
    }
}

四个相同的top0.xml

Fragment mTab01 = new WeixinFragment();
        Fragment mTab02 = new FrdFragment();
        Fragment mTab03 = new AddressFragment();
        Fragment mTab04 = new SettingFragment();