Fragment + ViewPager

//activity_main.xml

<?xml version="1.0" encoding="utf-8"?>

<android.support.v4.view.ViewPager
    android:id="@+id/viewpager"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="9"
    />
<RadioGroup
    android:id="@+id/group"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="1"
    android:orientation="horizontal"
    >
    <RadioButton
        android:layout_width="0dp"
        android:layout_weight="1"
        android:id="@+id/btn1"
        android:text="xlistview"
        android:checked="true"
        android:button="@null"
        android:gravity="center"
        android:background="@drawable/sel"
        android:textSize="20sp"
        android:layout_height="match_parent" />
    <RadioButton
        android:layout_width="0dp"
        android:layout_weight="1"
        android:id="@+id/btn2"
        android:text="首页"
        android:background="@drawable/sel"
        android:textSize="20sp"
        android:button="@null"
        android:gravity="center"
        android:layout_height="match_parent" />
    <RadioButton
        android:layout_width="0dp"
        android:layout_weight="1"
        android:id="@+id/btn3"
        android:text="朋友圈"
        android:background="@drawable/sel"
        android:textSize="20sp"
        android:button="@null"
        android:gravity="center"
        android:layout_height="match_parent" />

</RadioGroup>

//MainActivity

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.RadioGroup;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends FragmentActivity {
ViewPager viewPager;
RadioGroup group;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

    viewPager  =findViewById(R.id.viewpager);
    group = findViewById(R.id.group);


    //适配器
    viewPager.setAdapter(new FragmentPagerAdapter(getSupportFragmentManager()) {
        @Override
        public Fragment getItem(int i) {
            switch (i){
                case 0:
                    AFragment aFragment = new AFragment();
                    return aFragment;
                case 1:
                    BFragment bFragment = new BFragment();
                    return bFragment;
                case 2:
                    CFragment cFragment = new CFragment();
                    return cFragment;
            }
            return null;
        }

        @Override
        public int getCount() {

            return 3;
        }
    });


    group.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
        @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;

            }
        }
    });

    viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageScrolled(int i, float v, int i1) {

        }

        @Override
        public void onPageSelected(int i) {
             switch (i){
                 case 0:
                     group.check(R.id.btn1);
                     break;
                 case 1:
                     group.check(R.id.btn2);
                     break;
                 case 2:
                     group.check(R.id.btn3);
                     break;
             }
        }

        @Override
        public void onPageScrollStateChanged(int i) {

        }
    });

}

}