安卓滑动布局

0、目录结构

1、页面布局

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/activity_second"
    android:layout_width="match_parent"
    android:layout_height="match_parent">


    <android.support.v4.view.ViewPager
        android:id="@+id/vp"
        android:layout_above="@+id/radioGroup"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

    </android.support.v4.view.ViewPager>

    <RadioGroup
        android:id="@+id/radioGroup"
        android:orientation="horizontal"
        android:layout_alignParentBottom="true"
        android:layout_width="match_parent"
        android:layout_height="52dp">
        <RadioButton
            android:id="@+id/btn1"
            android:button="@null"
            android:text="消息"
            android:gravity="center"
            android:layout_weight="1"
            android:layout_width="wrap_content"
            android:layout_height="match_parent" />
        <RadioButton
            android:id="@+id/btn2"
            android:button="@null"
            android:text="联系人"
            android:gravity="center"
            android:layout_weight="1"
            android:layout_width="wrap_content"
            android:layout_height="match_parent" />
        <RadioButton
            android:id="@+id/btn3"
            android:button="@null"
            android:text="动态"
            android:gravity="center"
            android:layout_weight="1"
            android:layout_width="wrap_content"
            android:layout_height="match_parent" />
    </RadioGroup>

</RelativeLayout>

2、activity代码

public class SecondActivity extends Activity implements RadioGroup.OnCheckedChangeListener{

    private ViewPager viewPager;
    private ArrayList<View> pageViews;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second);
        initView();
        initFragment();
    }

    private void initFragment() {
        MessageFragment messageFragment=new MessageFragment();
        ContactsFragment contactsFragment=new ContactsFragment();
        TrendsFragment trendsFragment=new TrendsFragment();
        ArrayList<Fragment> fragments=new ArrayList<>();
        fragments.add(messageFragment);
        fragments.add(contactsFragment);
        fragments.add(trendsFragment);
        viewPager.setAdapter(new mPagerAdapter());
        //默认为消息页面
        viewPager.setCurrentItem(0);
    }

    private void initView() {
        viewPager = (ViewPager) findViewById(R.id.vp);
        RadioGroup radioGroup= (RadioGroup) findViewById(R.id.radioGroup);
        radioGroup.setOnCheckedChangeListener(this);
        //LayoutInflater获取View 与activity关联
        LayoutInflater inflater=getLayoutInflater();
        View message=inflater.inflate(R.layout.layout_message,null);
        View contacts=inflater.inflate(R.layout.layout_contacts,null);
        View trends=inflater.inflate(R.layout.layout_trends,null);

        pageViews = new ArrayList<>();
        pageViews.add(message);
        pageViews.add(contacts);
        pageViews.add(trends);
    }

    @Override
    public void onCheckedChanged(RadioGroup group, int checkedId) {
        switch (checkedId){
            case R.id.btn1:
                viewPager.setCurrentItem(0);
                break;
            case R.id.btn2:
                viewPager.setCurrentItem(1);
                break;
            case R.id.btn3:
                viewPager.setCurrentItem(2);
                break;
        }
    }

    private class mPagerAdapter extends PagerAdapter {
        @Override
        public int getCount() {
            return pageViews.size();
        }

        @Override
        public boolean isViewFromObject(View view, Object object) {
            return view==object;
        }
        @Override
        //使从ViewGroup中移出当前View
        public void destroyItem(View arg0, int arg1, Object arg2) {
            ((ViewPager) arg0).removeView(pageViews.get(arg1));
        }

        @Override
        //返回一个对象，这个对象表明了PagerAdapter适配器选择哪个对象放在当前的ViewPager中
        public Object instantiateItem(View arg0, int arg1) {
            ((ViewPager) arg0).addView(pageViews.get(arg1));
            return pageViews.get(arg1);
    }
}}

3、BaseFragment代码

public abstract class BaseFragment extends Fragment {
    public Activity mActivity;

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mActivity=getActivity();
    }

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view=initView();
        return view;

    }

    /**
        初始化布局 子类必须实现
     */
    public abstract View initView();

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        initData();
    }

    public void initData() {
    }
}

4、fragment代码

public class ContactsFragment extends BaseFragment {
    @Override
    public View initView() {
        View view=View.inflate(mActivity, R.layout.layout_contacts,null);
        return view;
    }
}

public class MessageFragment extends BaseFragment {
    @Override
    public View initView() {
        View view=View.inflate(mActivity, R.layout.layout_message,null);
        return view;
    }
}

public class TrendsFragment extends BaseFragment {
    @Override
    public View initView() {
        View view=View.inflate(mActivity, R.layout.layout_trends,null);
        return view;
    }
}