RadioGroup + Fragment + ViewPager + FragmentPagerAdapter实现

• 01 效果图
  该实现方式既可以通过切换RadioButton来切换页面，也可以通过左右滑动来切换页面。

MainInterface.png

• 02 layout
  4个fragment的相似布局文件

contact_fragment.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="match_parent"
    android:orientation="vertical"
    android:gravity="center">
    <TextView 
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Contact fragment"
        android:textSize="30sp"/>
</LinearLayout>

主布局文件

activity_main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
    <!--  使用ViewPager来管理页面 -->
    <android.support.v4.view.ViewPager 
        android:id="@+id/vp_content"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"/>
    <RadioGroup 
        android:id="@+id/rg_control"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:layout_gravity="bottom"
        android:gravity="center">
        <RadioButton
            android:id="@+id/rb_talk"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:layout_marginLeft="30dp"
            android:button="@drawable/radio_talk_selector"
            android:checked="true" />
        <RadioButton 
            android:id="@+id/rb_contact"
            android:layout_width="0dp"
            android:layout_weight="1"
            android:layout_height="wrap_content"
            android:button="@drawable/radio_contact_selector"/>
        <RadioButton 
            android:id="@+id/rb_discovery"
            android:layout_width="0dp"
            android:layout_weight="1"
            android:layout_height="wrap_content"
            android:button="@drawable/radio_discovery_selector"/>
        <RadioButton 
            android:id="@+id/rb_personal"
            android:layout_width="0dp"
            android:layout_weight="1"
            android:layout_height="wrap_content"
            android:button="@drawable/radio_personal_selector"/>
    </RadioGroup>
</LinearLayout>

• 03 Activity
  4个Fragment的相似Java代码

public class ContactFragment extends Fragment {
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // 这里注意inflate的第三个参数要设置为false
        View view = inflater.inflate(R.layout.contact_fragment, container, false);
        return view;
    }
}

MainActivity.java

public class MainActivity extends FragmentActivity implements OnCheckedChangeListener {
    // 用于对Fragment进行管理
    FragmentManager fragmentManager;
    private ViewPager vp_content;

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

    private void initUI() {
        vp_content = (ViewPager) findViewById(R.id.vp_content);
        final RadioGroup rg_control = (RadioGroup) findViewById(R.id.rg_control);
        rg_control.setOnCheckedChangeListener(this);
        final int radioIds[] = new int[]{R.id.rb_talk, R.id.rb_contact, R.id.rb_discovery, R.id.rb_personal};
        vp_content.setAdapter(new MyViewPagerAdpater(fragmentManager));
        vp_content.setOffscreenPageLimit(2);
        vp_content.setOnPageChangeListener(new OnPageChangeListener() {
            @Override
            public void onPageSelected(int position) {
                rg_control.check(radioIds[position]);
            }
            
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
            }
            
            @Override
            public void onPageScrollStateChanged(int arg0) {
            }
        });
    }
    
    class MyViewPagerAdpater extends FragmentPagerAdapter{
        private ArrayList<Fragment> mFragments;
        
        public MyViewPagerAdpater(android.support.v4.app.FragmentManager fm) {
            super(fm);
            initData();
        }
        
        private void initData() {
            mFragments= new ArrayList<Fragment>();
            TalkFragment talkFragment = new TalkFragment();
            ContactFragment contactFragment = new ContactFragment();
            DiscoveryFragment discoveryFragment = new DiscoveryFragment();
            PersonalFragment personalFragment = new PersonalFragment();
            mFragments.add(talkFragment);
            mFragments.add(contactFragment);
            mFragments.add(discoveryFragment);
            mFragments.add(personalFragment);
        }
        // 返回Fragment
        @Override
        public Fragment getItem(int position) {
            return mFragments.get(position);
        }
        // 返回Fragment的数量
        @Override
        public int getCount() {
            return mFragments.size();
        }
    }

    // Radio切换的事件处理
    @Override
    public void onCheckedChanged(RadioGroup radioGroup, int checkedId) {
        switch (checkedId) {
        case R.id.rb_talk:
            vp_content.setCurrentItem(0, true);
            break;
        case R.id.rb_contact:
            vp_content.setCurrentItem(1, true);
            break;
        case R.id.rb_discovery:
            vp_content.setCurrentItem(2, true);
            break;
        case R.id.rb_personal:
            vp_content.setCurrentItem(3, true);
            break;
        }
    }
}

• 04 横竖屏切换
  如果参考这个Demo后，在横竖屏切换时发现重叠问题，那么在AndroidManifest.xml文件中做如下设置。
  横竖屏切换时，activity不重新创建。

<activity
            android:name=".MainActivity"
            android:label="@string/app_name"
            android:configChanges="orientation|keyboardHidden|screenSize">

• 05 注意
  上述代码中需要使用android-support-v4.jar里面的Class：
  import android.support.v4.app.Fragment;
  import android.support.v4.app.FragmentActivity;
  import android.support.v4.app.FragmentManager;
  import android.support.v4.app.FragmentPagerAdapter;
  import android.support.v4.view.ViewPager;
  import android.support.v4.view.ViewPager.OnPageChangeListener;