Android fragment的切换+底部导航栏

新建一个加载他们的activity:
activity_mainxml：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <RadioGroup
        android:id="@+id/radioGroup"
        android:layout_width="match_parent"
        android:layout_height="55dp"
        android:layout_alignParentBottom="true"
        android:background="#f0f0f0"
        android:orientation="horizontal">
        <RadioButton
            android:id="@+id/rb_news"
            android:checked="true"
            android:text="新闻"
            android:drawableTop="@drawable/rb_news_selector"
            style="@style/style_RadioButton"/>
        <RadioButton
            android:id="@+id/rb_thing"
            android:text="装备库"
            android:drawableTop="@drawable/rb_thing_selector"
            style="@style/style_RadioThingButton"/>
        <RadioButton
            android:id="@+id/rb_me"
            android:text="我"
            android:drawableTop="@drawable/rb_me_selector"
            style="@style/style_RadioButton"/>
    </RadioGroup>

    <com.example.chen.briupnes.util.CustomViewPager
        android:id="@+id/viewPager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@id/radioGroup" />
</RelativeLayout>

自定义ViewPager禁止左右滑动

public class CustomViewPager extends ViewPager {

    private boolean isCanScroll = true;

    public CustomViewPager(Context context) {
        super(context);
    }

    public CustomViewPager(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    /**
     * 设置其是否能滑动换页
     * @param isCanScroll false 不能换页， true 可以滑动换页
     */
    public void setScanScroll(boolean isCanScroll) {
        this.isCanScroll = isCanScroll;
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        return isCanScroll && super.onInterceptTouchEvent(ev);
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        return isCanScroll && super.onTouchEvent(ev);

    }
}

MainActivity:

 private void initView() {
       
        rb_news = (RadioButton) findViewById(R.id.rb_news);
        rb_thing = (RadioButton) findViewById(R.id.rb_thing);
        rb_me = (RadioButton) findViewById(R.id.rb_me);
        radioGroup = (RadioGroup) findViewById(R.id.radioGroup);
        viewPager = (CustomViewPager) findViewById(R.id.viewPager);
        viewPager.setScanScroll(false);
            radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
                @Override
                public void onCheckedChanged(RadioGroup group, int checkedId) {
                    switch (checkedId){
                        case R.id.rb_news:
                            /**
                             * setCurrentItem第二个参数控制页面切换动画
                             * true:打开/false:关闭
                             */
                            viewPager.setCurrentItem(0, false);
                            break;
                        case R.id.rb_thing:
                            /**
                             * setCurrentItem第二个参数控制页面切换动画
                             * true:打开/false:关闭
                             */
                            viewPager.setCurrentItem(1, false);
                            break;
                        case R.id.rb_me:
                            /**
                             * setCurrentItem第二个参数控制页面切换动画
                             * true:打开/false:关闭
                             */      
                                viewPager.setCurrentItem(2, false);                    
                            break;
                    }
                }
            });
            MeFragment meFragment = new MeFragment();
            NewsFragment newsFragment = new NewsFragment();
            ThingFragment thingFragment = new ThingFragment();
            List<Fragment> alFragment = new ArrayList<Fragment>();
            alFragment.add(newsFragment);
            alFragment.add(thingFragment);
            alFragment.add(meFragment);
            viewPager.setAdapter(new MyFragmentPagerAdapter(getSupportFragmentManager(),alFragment));
            //ViewPager显示第一个Fragment
            viewPager.setCurrentItem(0);
       /* //页面的切换
        viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {
                switch (position) {
                    case 0:
                        radioGroup.check(R.id.rb_news);
                        break;
                    case 1:
                        radioGroup.check(R.id.rb_thing);
                        break;
                    case 2:
                        radioGroup.check(R.id.rb_me);
                        break;

                }

            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });*/




        }

fragmentadapter

public class MyFragmentPagerAdapter extends FragmentPagerAdapter {
    private List<Fragment> list;

    public MyFragmentPagerAdapter(FragmentManager fm, List<Fragment> list) {
        super(fm);
        this.list = list;
    }

    @Override
    public Fragment getItem(int position) {
        return list.get(position);
    }

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

viewpager的预加载：
我的是当点击到fragment时进行网络请求：
BaseFragment:

public abstract class BaseFragment extends Fragment {

    private static final String TAG = BaseFragment.class.getSimpleName();

    private boolean isFragmentVisible;
    private boolean isReuseView;
    private boolean isFirstVisible;
    private View rootView;


    //setUserVisibleHint()在Fragment创建时会先被调用一次，传入isVisibleToUser = false
    //如果当前Fragment可见，那么setUserVisibleHint()会再次被调用一次，传入isVisibleToUser = true
    //如果Fragment从可见->不可见，那么setUserVisibleHint()也会被调用，传入isVisibleToUser = false
    //总结：setUserVisibleHint()除了Fragment的可见状态发生变化时会被回调外，在new Fragment()时也会被回调
    @Override
    public void setUserVisibleHint(boolean isVisibleToUser) {
        super.setUserVisibleHint(isVisibleToUser);
        //setUserVisibleHint()有可能在fragment的生命周期外被调用
        if (rootView == null) {
            return;
        }
        if (isFirstVisible && isVisibleToUser) {
            onFragmentFirstVisible();
            isFirstVisible = false;
        }
        if (isVisibleToUser) {
            onFragmentVisibleChange(true);
            isFragmentVisible = true;
            return;
        }
        if (isFragmentVisible) {
            isFragmentVisible = false;
            onFragmentVisibleChange(false);
        }
    }

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        initVariable();
    }

    @Override
    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
        //如果setUserVisibleHint()在rootView创建前调用时，那么
        //就等到rootView创建完后才回调onFragmentVisibleChange(true)
        //保证onFragmentVisibleChange()的回调发生在rootView创建完成之后，以便支持ui操作
        if (rootView == null) {
            rootView = view;
            if (getUserVisibleHint()) {
                if (isFirstVisible) {
                    onFragmentFirstVisible();
                    isFirstVisible = false;
                }
                onFragmentVisibleChange(true);
                isFragmentVisible = true;
            }
        }
        super.onViewCreated(isReuseView && rootView != null ? rootView : view, savedInstanceState);
    }

    @Override
    public void onDestroyView() {
        super.onDestroyView();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        initVariable();
    }

    private void initVariable() {
        isFirstVisible = true;
        isFragmentVisible = false;
        rootView = null;
        isReuseView = true;
    }

    /**
     *
     * @param isReuse
     */
    protected void reuseView(boolean isReuse) {
        isReuseView = isReuse;
    }

    /**
     * 去除setUserVisibleHint()多余的回调场景，保证只有当fragment可见状态发生变化时才回调
     * 回调时机在view创建完后，所以支持ui操作，解决在setUserVisibleHint()里进行ui操作有可能报null异常的问题
     *
     * 可在该回调方法里进行一些ui显示与隐藏
     *
     * @param isVisible true  不可见 -> 可见
     *                  false 可见  -> 不可见
     */
    protected void onFragmentVisibleChange(boolean isVisible) {

    }

    /**
     * 在fragment首次可见时回调，可用于加载数据，防止每次进入都重复加载数据
     */
    protected void onFragmentFirstVisible() {

    }

    protected boolean isFragmentVisible() {
        return isFragmentVisible;
    }
}

在Fragment中的调用例子：

public class NewsFragment extends BaseFragment {

    private View rootView;
    private ListView lv_news;
    private NewsAdapter adapter;
    private  List<News> list = new ArrayList<News>();
    private final String TAG="NewsFragment";

    public NewsFragment() {
    }

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        if(rootView == null){
            rootView = inflater.inflate(R.layout.fragment_news,container,false);
            initView(rootView);
        }
        ViewGroup parent = (ViewGroup) rootView.getParent();
        if (parent != null) {
            parent.removeView(rootView);
        }
        return rootView;
    }

    private void initView(View view) {
        lv_news = (ListView) view.findViewById(R.id.lv_news);
    }

    private void setNewsData() {
        new Thread(new Runnable() {
            @Override
            public void run() {
                OkHttpUtils.get()
                        .url("http://10.0.3.2:9999/ssh/data")
                        .build()
                        .execute(new StringCallback() {
                            @Override
                            public void onError(Call call, final Exception e, int id) {
                                getActivity().runOnUiThread(new Runnable() {
                                    @Override
                                    public void run() {
                                        Toast.makeText(getContext(),"数据加载失败，请检查网络连接",Toast.LENGTH_SHORT).show();
                                    }
                                });

                            }

                            @Override
                            public void onResponse(String response, int id) {
                                if(response.toString().contains("error")){
                                    getActivity().runOnUiThread(new Runnable() {
                                        @Override
                                        public void run() {
                                            Toast.makeText(getContext(),"数据获取失败",Toast.LENGTH_SHORT).show();
                                        }
                                    });
                                }else{
                                    Gson gson = new Gson();
                                    Type type = new TypeToken<ArrayList<News>>(){}.getType();
                                    list = gson.fromJson(response.toString(), type);
                                    Log.e(TAG,list.toString());
                                    adapter = new NewsAdapter(list,getContext());
                                    lv_news.setAdapter(adapter);
                                }
                            }
                        });

            }
        }).start();
    }

    @Override
    protected void onFragmentVisibleChange(boolean isVisible) {
        super.onFragmentVisibleChange(isVisible);
        if(isVisible){
           //模拟加载其他的数据
           setNewsData();
        }else{

        }
    }

    @Override
    protected void onFragmentFirstVisible() {
        super.onFragmentFirstVisible();
        setNewsData();
    }
}

下方图标设置：
values 中 新建一个styles.xml

<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- Customize your theme here. -->
        <item name="android:colorPrimary">@color/white</item>
    </style>
    <style name="style_RadioButton">
        <item name="android:layout_width">match_parent</item>
        <item name="android:layout_height">wrap_content</item>
        <item name="android:button">@null</item>
        <item name="android:background">@null</item>
        <item name="android:layout_weight">1</item>
        <item name="android:gravity">center</item>
        <item name="android:layout_gravity">center</item>
        <item name="android:textColor">@drawable/rb_focus_color</item>
        <item name="android:textSize">12sp</item>
    </style>
    <style name="style_RadioThingButton">
        <item name="android:layout_width">match_parent</item>
        <item name="android:layout_height">wrap_content</item>
        <item name="android:button">@null</item>
        <item name="android:background">@null</item>
        <item name="android:layout_weight">1</item>
        <item name="android:gravity">center</item>
        <item name="android:layout_gravity">center</item>
        <item name="android:textColor">@drawable/rb_focus_thing_color</item>
        <item name="android:textSize">12sp</item>
    </style>

</resources>

调用时见activity_main.xml中