App主界面布局的实现方式（一）

RadioGroup + Fragment实现

• 01 效果图
  该实现方式只能通过切换RadioButton来切换页面，并不能通过滑动来实现。

MainInterface.png

• 02 layout
  4个fragment的相似布局文件

  contact_fragment.xml
  
  <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

  <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
    
    <FrameLayout 
        android:id="@+id/fl_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 Activity implements OnCheckedChangeListener {
    // 用于对Fragment进行管理
    private FragmentManager fragmentManager;
    private TalkFragment talkFragment;
    private ContactFragment contactFragment;
    private DiscoveryFragment discoveryFragment;
    private PersonalFragment personalFragment;
  
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_main);
        fragmentManager = getFragmentManager();
        initUI();
    }
  
    private void initUI() {
        RadioGroup rg_control = (RadioGroup) findViewById(R.id.rg_control);
        rg_control.setOnCheckedChangeListener(this);
        // 设置默认的Fragment
        setDefaultFragment();
    }
  
    private void setDefaultFragment() {
        FragmentTransaction transaction = fragmentManager.beginTransaction();
        talkFragment = new TalkFragment();
        transaction.add(R.id.fl_content, talkFragment);
        transaction.commit();
    }
  
    // Radio切换的事件处理
    @Override
    public void onCheckedChanged(RadioGroup radioGroup, int checkedId) {
        switch (checkedId) {
        case R.id.rb_talk:
            setTabSelection(0);
            break;
        case R.id.rb_contact:
            setTabSelection(1);
            break;
        case R.id.rb_discovery:
            setTabSelection(2);
            break;
        case R.id.rb_personal:
            setTabSelection(3);
            break;
        }
    }
  
    private void setTabSelection(int index) {
        // 开启一个Fragment事务
        FragmentTransaction transaction = fragmentManager.beginTransaction();
        // 先隐藏掉所有的Fragment
        hideFragments(transaction);
        switch (index) {
        case 0:
            if (talkFragment == null) {
                // 如果TalkFragment为空，则创建一个并添加到界面上
                talkFragment = new TalkFragment();
                transaction.add(R.id.fl_content, talkFragment);
            } else {
                // 如果TalkFragment不为空，则直接将它显示出来
                transaction.show(talkFragment);
            }
            break;
        case 1:
            if (contactFragment == null) {
                contactFragment = new ContactFragment();
                transaction.add(R.id.fl_content, contactFragment);
            } else {
                transaction.show(contactFragment);
            }
            break;
        case 2:
            if (discoveryFragment == null) {
                discoveryFragment = new DiscoveryFragment();
                transaction.add(R.id.fl_content, discoveryFragment);
            } else {
                transaction.show(discoveryFragment);
            }
            break;
        case 3:
            if (personalFragment == null) {
                personalFragment = new PersonalFragment();
                transaction.add(R.id.fl_content, personalFragment);
            } else {
                transaction.show(personalFragment);
            }
            break;
        }
        transaction.commit();
    }
  
    /**
     * 将所有的Fragment都置为隐藏状态。
     * 
     * @param transaction
     *            用于对Fragment执行操作的事务
     */
    private void hideFragments(FragmentTransaction transaction) {
        if (talkFragment != null) {
            transaction.hide(talkFragment);
        }
        if (contactFragment != null) {
            transaction.hide(contactFragment);
        }
        if (discoveryFragment != null) {
            transaction.hide(discoveryFragment);
        }
        if (personalFragment != null) {
            transaction.hide(personalFragment);
        }
    }
  }

• 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">

文／RickGe（简书作者）
原文链接：http://www.jianshu.com/p/3ccbe1a94b5b
著作权归作者所有，转载请联系作者获得授权，并标注“简书作者”。