Android使用RadioGroup实现底部导航栏

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:orientation="vertical" android:layout_width="match_parent"
 android:layout_height="match_parent">
 <TextView
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:gravity="center"
 android:textSize="50sp"
 android:textColor="@color/colorPrimary"
 android:text="home"/>
</LinearLayout>

public class FrHome extends Fragment {

 @Nullable
 @Override
 public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
 View view = LayoutInflater.from(getContext()).inflate(R.layout.fragment_home, container, false);
 return view;
 }

}

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
 <item android:state_checked="true" android:color="#3F51B5"/>
 <item android:state_checked="false" android:color="#8f8f8f"/>
</selector>

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
 <item android:state_checked="true" android:drawable="@mipmap/ic_history_checked"/>
 <item android:state_checked="false" android:drawable="@mipmap/ic_history_unchecked"/>
</selector>

<?xml version="1.0" encoding="utf-8"?>
<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"
 xmlns:app="http://schemas.android.com/apk/res-auto"
 tools:context="com.lotus.chartspagedemo.ActHome">

 <FrameLayout
 android:id="@+id/frame_layout"
 android:layout_width="match_parent"
 android:layout_above="@+id/card_view"
 android:layout_height="match_parent"/>

 <android.support.v7.widget.CardView
 android:id="@+id/card_view"
 app:cardElevation="25dp"
 android:layout_alignParentBottom="true"
 android:layout_width="match_parent"
 android:layout_height="wrap_content">
 <RadioGroup
  android:paddingTop="5dp"
  android:id="@+id/tab_bar"
  android:background="@color/app_white"
  android:layout_width="match_parent"
  android:layout_height="60dp"
  android:gravity="center"
  android:orientation="horizontal">
  <RadioButton
  android:id="@+id/tab_home"
  android:gravity="center"
  android:button="@null"
  android:drawableTop="@drawable/selector_tab_home"
  android:layout_width="0dp"
  android:layout_weight="1"
  android:layout_height="match_parent"
  android:textColor="@drawable/selector_tab_color"
  android:text="首页"/>
  <RadioButton
  android:id="@+id/tab_health"
  android:gravity="center"
  android:button="@null"
  android:drawableTop="@drawable/selector_tab_health"
  android:layout_width="0dp"
  android:layout_weight="1"
  android:layout_height="match_parent"
  android:textColor="@drawable/selector_tab_color"
  android:text="体检测评" />
  <RadioButton
  android:id="@+id/tab_personal"
  android:gravity="center"
  android:button="@null"
  android:drawableTop="@drawable/selector_tab_personal"
  android:layout_width="0dp"
  android:layout_weight="1"
  android:layout_height="match_parent"
  android:textColor="@drawable/selector_tab_color"
  android:text="个人中心"
  />
 </RadioGroup>
 </android.support.v7.widget.CardView>

</RelativeLayout>

public class ActHome extends FragmentActivity implements RadioGroup.OnCheckedChangeListener {

 @BindView(R.id.frame_layout)
 FrameLayout frameLayout;
 @BindView(R.id.tab_home)
 RadioButton tabHome;
 @BindView(R.id.tab_health)
 RadioButton tabHealth;
 @BindView(R.id.tab_personal)
 RadioButton tabPersonal;
 @BindView(R.id.tab_bar)
 RadioGroup tabBar;

 public final static String ACTION_EXIT_SYSTEM = "sys_exit";

 private FragmentManager manager;
 private FragmentTransaction transaction;
 private FrHome frHome;
 private FrHealth frHealth;
 private FrPersonal frPersonal;
 private long mExitTime;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_home);
 ButterKnife.bind(this);
 RadioButton tabHome = (RadioButton) tabBar.getChildAt(0);
 tabHome.setChecked(true);
 tabBar.setOnCheckedChangeListener(this);
 initFragment();
 }

 private void initFragment() {
 manager = getSupportFragmentManager();
 transaction = manager.beginTransaction();
 frHome = new FrHome();
 transaction.add(R.id.frame_layout,frHome);
 transaction.commit();
 }

 @Override
 public void onCheckedChanged(RadioGroup radioGroup, @IdRes int checkedId) {
 switch (checkedId) {
  case R.id.tab_home:
  FragmentTransaction ft1 = manager.beginTransaction();
  hideAll(ft1);
  if (frHome!=null){
   ft1.show(frHome);
  }else {
   frHome=new FrHome();
   ft1.add(R.id.frame_layout,frHome);
  }
  ft1.commit();
  break;
  case R.id.tab_health:
  FragmentTransaction ft2 = manager.beginTransaction();
  hideAll(ft2);
  if (frHealth!=null){
   ft2.show(frHealth);
  }else {
   frHealth = new FrHealth();
   ft2.add(R.id.frame_layout,frHealth);
  }
  ft2.commit();
  break;
  case R.id.tab_personal:
  FragmentTransaction ft5 = manager.beginTransaction();
  hideAll(ft5);
  if (frPersonal!=null){
   ft5.show(frPersonal);
  }else {
   frPersonal = new FrPersonal();
   ft5.add(R.id.frame_layout, frPersonal);
  }
  ft5.commit();
  break;
 }
 }

 private void hideAll(FragmentTransaction ft){
 if (ft==null){
  return;
 }
 if (frHome!=null){
  ft.hide(frHome);
 }
 if (frHealth!=null){
  ft.hide(frHealth);
 }
 if (frPersonal!=null){
  ft.hide(frPersonal);
 }
 }

 @Override
 public void onBackPressed() {
 if ((System.currentTimeMillis() - mExitTime) > 2000) {
  Toast.makeText(ActHome.this,"再按一次退出程序",Toast.LENGTH_SHORT).show();
  mExitTime = System.currentTimeMillis();
 } else {
  new Handler().postDelayed(new Runnable() {
  @Override
  public void run() {
   onExit(ActHome.this);
  }
  }, 500);
 }
 }

 public static void onExit(final Context context) {
 try {
  Intent intent = new Intent();
  intent.setAction(context.getApplicationContext().getPackageName() + ACTION_EXIT_SYSTEM);
  context.sendBroadcast(intent);
  // MobclickAgent.onKillProcess(context);
  new Handler().postDelayed(new Runnable() {
  @Override
  public void run() {
   System.exit(0);
  }
  }, 200);
 } catch (Exception e) {
  e.printStackTrace();
 }
 }
}