Android中fragment+viewpager实现布局

<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"   xmlns:app="http://schemas.android.com/apk/res-auto"   xmlns:tools="http://schemas.android.com/tools"   android:layout_width="match_parent"   android:layout_height="match_parent"   tools:context="com.bwei.fragment.MainActivity">    <android.support.v4.view.ViewPager     android:id="@+id/pager"     android:layout_width="wrap_content"     android:layout_height="wrap_content" />    <RadioGroup     android:id="@+id/radioGroup1"     android:layout_width="match_parent"     android:layout_height="wrap_content"     android:layout_alignBottom="@+id/pager"     android:layout_centerHorizontal="true"     android:orientation="horizontal"     android:background="#ccc"     >      <RadioButton       android:id="@+id/radio0"       android:layout_width="0dp"       android:layout_height="match_parent"       android:checked="true"       android:button="@null"       android:layout_weight="1"       android:text="微信"       android:drawableTop="@mipmap/ic_launcher_round"       android:gravity="center"       />      <RadioButton       android:id="@+id/radio1"       android:layout_width="0dp"       android:layout_height="match_parent"       android:button="@null"       android:layout_weight="1"       android:text="通讯录"       android:drawableTop="@mipmap/ic_launcher_round"       android:gravity="center"       />      <RadioButton       android:id="@+id/radio2"       android:layout_width="0dp"       android:layout_height="match_parent"       android:button="@null"       android:layout_weight="1"       android:text="发现"       android:drawableTop="@mipmap/ic_launcher_round"       android:gravity="center" />     <RadioButton       android:id="@+id/radio3"       android:layout_width="0dp"       android:layout_height="wrap_content"       android:button="@null"       android:layout_weight="1"       android:text="我的"       android:drawableTop="@mipmap/ic_launcher_round"       android:gravity="center"/>   </RadioGroup> </RelativeLayout> 

public class FragmentThree extends Fragment {   @Nullable   @Override   public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {      //引入布局文件     View view = inflater.inflate(R.layout.fragmentthree, null);     return view;   } } 

<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"   android:layout_width="match_parent"   android:layout_height="match_parent">     <TextView     android:id="@+id/textView"     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:layout_alignParentTop="true"     android:layout_centerHorizontal="true"     android:layout_marginTop="230dp"     android:text="one" /> </RelativeLayout> 

package com.bwei.fragment;  import android.content.Context; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentManager; import android.support.v4.app.FragmentPagerAdapter;  import java.util.List;   public class MyAdapter extends FragmentPagerAdapter {   private List<Fragment> fragments;   private Context context;   //构造方法   public MyAdapter(FragmentManager fm, List<Fragment> fragments, Context context) {     super(fm);     this.fragments = fragments;     this.context = context;   }   //得到item条目   @Override   public Fragment getItem(int position) {     return fragments.get(position);   }    //得到数量   @Override   public int getCount() {     return fragments.size();   } } 

package com.bwei.fragment;  import android.graphics.Color; import android.os.Bundle; import android.support.annotation.IdRes; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentManager; import android.support.v4.view.ViewPager; import android.support.v7.app.AppCompatActivity; import android.widget.RadioButton; import android.widget.RadioGroup; import android.widget.Toast;  import java.util.ArrayList; import java.util.List;  public class MainActivity extends AppCompatActivity implements RadioGroup.OnCheckedChangeListener,ViewPager.OnPageChangeListener {    private ViewPager vPager;   private List<Fragment> fragments;   private FragmentManager fm;   private RadioGroup mRadioGroup;   @Override   protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_main);     //初始化控件     initView();     initDate();   }    private void initView() {     vPager=(ViewPager) findViewById(R.id.pager);     vPager.setOnPageChangeListener(this);     mRadioGroup=(RadioGroup) findViewById(R.id.radioGroup1);     mRadioGroup.setOnCheckedChangeListener(this);   }    private void initDate() {     fragments=new ArrayList<Fragment>();     //实例化Fragment     FragmentOne fragmentOne = new FragmentOne();     FragmentTwo fragmentTwo = new FragmentTwo();     FragmentThree fragmentThree = new FragmentThree();      //添加到集合     fragments.add(fragmentOne);     fragments.add(fragmentTwo);     fragments.add(fragmentThree);      //得到getSupportFragmentManager()的管理器     fm = getSupportFragmentManager();     //得到适配器     MyAdapter myAdapter = new MyAdapter(fm, fragments, this);     //设置适配器     vPager.setAdapter(myAdapter);   }    //ViewPager.OnPageChangeListener监听事件   @Override   public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {    }    @Override   public void onPageSelected(int position) {      for (int i = 0; i <fragments.size() ; i++) {       RadioButton radiobutton = (RadioButton) mRadioGroup.getChildAt(i);       if (i==position) {         radiobutton.setChecked(true);         //设置选中的颜色         radiobutton.setBackgroundColor(Color.RED);       }else {         radiobutton.setChecked(false);         radiobutton.setBackgroundColor(Color.BLACK);         radiobutton.setBackgroundColor(Color.BLACK);       }     }   }    @Override   public void onPageScrollStateChanged(int state) {    }    //RadioGroup的监听事件    @Override   public void onCheckedChanged(RadioGroup radioGroup, @IdRes int i) {      for (int j = 0; j <fragments.size() ; j++) {       //得到radiobutton       RadioButton radiobutton = (RadioButton) mRadioGroup.getChildAt(j);       int id = radiobutton.getId();       Toast.makeText(this,id+"", Toast.LENGTH_SHORT).show();       //判断radiobutton的id是否等于选中的id       if (radiobutton.getId()==i) {         //设置当前页         vPager.setCurrentItem(j);       }     }   } }