<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    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"
    android:background="#ffffff"
    android:orientation="vertical"
    tools:context="com.lyx.mycommunity.app.MainActivity">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/tv_user"/>
    <FrameLayout
    android:id="@+id/frameLayout"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="1" />
    <RadioGroup
        android:id="@+id/rg_main"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:background="@drawable/home_bottom_parent_bg"
        android:orientation="horizontal">
        <RadioButton
            android:id="@+id/rb_home"
            style="@style/MainButtonStyle"
            android:drawableTop="@drawable/home_button_selector"
            android:text=" 首页" />
        <RadioButton
            android:id="@+id/rb_category"
            style="@style/MainButtonStyle"
            android:drawableTop="@drawable/category_button_selector"
            android:text=" 服务" />
        <RadioButton
            android:id="@+id/rb_community"
            style="@style/MainButtonStyle"
            android:drawableTop="@drawable/community_button_selector"
            android:paddingTop="10dp"
            android:text=" 新闻" />
        <RadioButton
            android:id="@+id/rb_search"
            style="@style/MainButtonStyle"
            android:drawableTop="@drawable/cart_button_selector"
            android:text=" 搜索" />
        <RadioButton
            android:id="@+id/rb_user"
            style="@style/MainButtonStyle"
            android:drawableTop="@drawable/user_button_selector"
            android:text=" 个人中心" />
    </RadioGroup>

</LinearLayout>

2. 新建一个类继承Fragment类或者他的子类,重写onCreateView()和onActivityCreated()方法 在onCreateView()方法中调用:inflater.inflate()方法加载Fragment的布局文件,并返回加载的view对象

package com.lyx.mycommunity.base;


import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;

public abstract class BaseFragment extends Fragment {
  public Context myContext;


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

  }

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

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

  /**
   *由子类实现，实现特有效果
   * @return
   */
  public abstract View initView();

  /**
   * 初始化数据
   */
  public void initData() {

  }


}

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

fragments = new ArrayList<>();
fragments.add(new HomeFragment());
fragments.add(new ServiceFragment());
fragments.add(new NewsFragment());
fragments.add(new SearchFragment());
fragments.add(new UserFragment());

package com.lyx.mycommunity.app;

import android.content.Intent;
import android.os.Bundle;

import android.widget.FrameLayout;
import android.widget.ImageButton;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.TextView;

import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentActivity;
import androidx.fragment.app.FragmentTransaction;
import androidx.recyclerview.widget.RecyclerView;

import com.lyx.mycommunity.adapter.HomeRecycleAdapter;
import com.lyx.mycommunity.base.BaseFragment;
import com.lyx.mycommunity.fragment.ServiceFragment;
import com.lyx.mycommunity.fragment.NewsFragment;
import com.lyx.mycommunity.fragment.HomeFragment;
import com.lyx.mycommunity.fragment.UserFragment;
import com.lyx.mycommunity.utils.BatteryChangeReceiver;
import com.lyx.shoppingcity.R;
import com.lyx.mycommunity.fragment.SearchFragment;

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

import butterknife.Bind;
import butterknife.ButterKnife;

public class MainActivity extends FragmentActivity {

    @Bind(R.id.frameLayout)
    FrameLayout frameLayout;
    @Bind(R.id.rb_home)
    RadioButton rbHome;
    @Bind(R.id.rb_category)
    RadioButton rbType;
    @Bind(R.id.rb_community)
    RadioButton rbCommunity;
    @Bind(R.id.rb_search)
    RadioButton rbSearch;
    @Bind(