一、新闻列表使用RecyclerView,添加依赖库
步骤如下：





二、新建新闻实体类

package com.example.fragmentbestpractice;

public class News { 
    
    private String title;
    private String content;

    public String getTitle() { 
        return title;
    }

    public void setTitle(String title) { 
        this.title = title;
    }

    public String getContent() { 
        return content;
    }

    public void setContent(String content) { 
        this.content = content;
    }
}

三、新建布局文件，作为新闻内容的布局

<?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">
    <!--
    新闻内容的布局：头部显示新闻标题，正文显示新闻内容
    -->
    <LinearLayout
        android:id="@+id/visibility_layout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:visibility="invisible">

        <TextView
            android:id="@+id/news_title"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:padding="10dp"
            android:textSize="20sp"/>
        <View
            android:layout_width="match_parent"
            android:layout_height="1dp"
            android:background="#000"/>
        <TextView

            android:id="@+id/news_content"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1"
            android:padding="15dp"
            android:textSize="18sp"/>
    </LinearLayout>
    <View
        android:layout_width="1dp"
        android:layout_height="match_parent"
        android:layout_alignParentLeft="true"
        android:background="#000"/>
</RelativeLayout>

四、新建NewsContentFragment类，创建好新闻内容的碎片

package com.example.fragmentbestpractice;

import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

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

import org.w3c.dom.Text;

public class NewsContentFragment extends Fragment { 
    private View view;
    

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { 
        view=inflater.inflate(R.layout.news_content_frag,container,false);
        return view;
    }
    
    public void refresh(String newsTitle,String newsContent){ 
        View visibilityLayout=view.findViewById(R.id.visibility_layout);
        visibilityLayout.setVisibility(View.VISIBLE);
        TextView newsTitleText=(TextView) view.findViewById(R.id.news_title);
        TextView newsContentText=(TextView) view.findViewById(R.id.news_content);
        
        newsTitleText.setText(newsTitle);
        newsContentText.setText(newsContent);
    }
}

五、新建一个活动，用于在单页模式中使用

修改布局文件中的代码

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <!--
    通过代码的复用性，在此布局文件中直接引入NewsContentFragment相当于把news_content_frag
    布局的内容自动加了进来
    -->
    <fragment
        android:id="@+id/news_content_fragment"
        android:name="com.example.fragmentbestpractice.NewsContentFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        />
</LinearLayout>

六、修改NewsContentActivity中的代码

package com.example.fragmentbestpractice;

import androidx.appcompat.app.AppCompatActivity;

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

public class NewsContentActivity extends AppCompatActivity { 
    
    public static void antionStart(Context context,String newsTitle,String newsContent){ 
        Intent intent=new Intent(context,NewsContentActivity.class);
        intent.putExtra("news_title",newsTitle);
        intent.putExtra("news_content",newsContent);
        context.startActivity(intent);
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.news_content);
        
        String newsTitle=getIntent().getStringExtra("news_title");
        String newsContent=getIntent().getStringExtra("news_content");
        NewsContentFragment newsContentFragment=(NewsContentFragment) getSupportFragmentManager().findFragmentById(R.id.news_content_fragment);
        newsContentFragment.refresh(newsTitle,newsContent);
        
    }
}

七、创建用于显示新闻列表的布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <!--用于显示新闻列表的RecyclerView-->
    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/news_title_recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        />
</LinearLayout>

八、新建RecyclerView子项的布局

<?xml version="1.0" encoding="utf-8"?>
<!--android:padding表示给控件的周围加上补白
    android:maxLines="1"表示这个TextView只能单行显示
    android:ellipsize设定当文本内容超出控件宽度时，文本的缩略方式，在尾部进行缩略-->
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/news_title"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:maxLines="1"
    android:ellipsize="end"
    android:textSize="18sp"
    android:paddingLeft="10dp"
    android:paddingRight="10dp"
    android:paddingTop="15dp"
    android:paddingBottom="15dp"/>

九、新建NewsTitleFragment类用于展示新闻列表的碎片

package com.example.fragmentbestpractice;

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

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

public class NewsTitleFragment extends Fragment { 
    private boolean isTwoPane;

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { 
        View view=inflater.inflate(R.layout.news_title_frag,container,false);
        return view;
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) { 
        super.onActivityCreated(savedInstanceState);
        
        if (getActivity().findViewById(R.id.news_content_layout)!=null){ 
            isTwoPane=true;
        }else{ 
            isTwoPane=false;
        }
    }
}

十、修改activity_main.xml中的代码，使得在单页模式下，只会加载一个新闻标题的碎片

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/news_title_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <!--单页模式下只会加载一个新闻标题的碎片-->
    <fragment
        android:id="@+id/news_title_fragment"
        android:name="com.example.fragmentbestpractice.NewsTitleFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>
</FrameLayout>

十一、新建文件夹以及布局文件，使得双页模式下引入两个碎片

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <fragment
        android:id="@+id/news_title_fragment"
        android:name="com.example.fragmentbestpractice.NewsTitleFragment"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="1"/>
    <!--将新闻内容的碎片放在FrameLayout布局下，此布局ID正好是news_content_layout
    因此能找到此id就是双页模式-->
    <FrameLayout
        android:id="@+id/news_content_layout"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="3">

        <fragment
            android:id="@+id/news_content_fragment"
            android:name="com.example.fragmentbestpractice.NewsContentFragment"
            android:layout_width="match_parent"
            android:layout_height="match_parent"/>
    </FrameLayout>
</LinearLayout>

十二、在NewsTitleFragment中通过RecyclerView将新闻列表展示出来，需要在 NewsTitleFragment中新建内部类NewsAdapter作为RecyclerView的适配器

 
    class NewsAdapter extends RecyclerView.Adapter<NewsAdapter.ViewHolder>{ 
        private List<News> mNewsList;

        class ViewHolder extends RecyclerView.ViewHolder { 
            TextView newsTitleText;
            public ViewHolder(@NonNull View itemView) { 
                super(itemView);
                newsTitleText=(TextView) itemView.findViewById(R.id.news_title);
            }
        }
        public NewsAdapter(List<News> newsList){ 
            mNewsList=newsList;
        }

        @NonNull
        @Override
        public NewsAdapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) { 
            View view=LayoutInflater.from(parent.getContext()).inflate(R.layout.news_item,parent,false);
            final ViewHolder holder=new ViewHolder(view);
            view.setOnClickListener(new View.OnClickListener() { 
                
                @Override
                public void onClick(View v) { 
                    News news=mNewsList.get(holder.getAdapterPosition());
                    if (isTwoPane){ 
                        NewsContentFragment newsContentFragment=(NewsContentFragment) getFragmentManager().findFragmentById(R.id.news_content_fragment);
                        newsContentFragment.refresh(news.getTitle(),news.getContent());
                    }else{ 
                        NewsContentActivity.actionStart(getActivity(),news.getTitle(),news.getContent());
                    }
                }
            });
            return holder;
        }

        @Override
        public void onBindViewHolder(@NonNull NewsAdapter.ViewHolder holder, int position) { 
            News news=mNewsList.get(position);
            holder.newsTitleText.setText(news.getTitle());
        }

        @Override
        public int getItemCount() { 
            return mNewsList.size();
        }

    }

十三、向RecyclerView中填充数据，继续修改NewsTitleFragment的代码：

在onCreateView方法中新增代码

        RecyclerView newsTitleRecyclerView=(RecyclerView) view.findViewById(R.id.news_title_recycler_view);
        LinearLayoutManager layoutManager=new LinearLayoutManager(getActivity());
        newsTitleRecyclerView.setLayoutManager(layoutManager);
        NewsAdapter adapter=new NewsAdapter(getNews());
        newsTitleRecyclerView.setAdapter(adapter);
        return view;
    }

    private List<News> getNews() { 
        List<News> newsList=new ArrayList<>();
        for(int i=0;i<=50;i++){ 
            News news=new News();
            news.setTitle("This is news title"+i);
            news.setContent(getRandomLengthContent("This is news Content"+i+"."));
            newsList.add(news);
        }
        return newsList;
    }

    private String getRandomLengthContent(String content) { 
        Random random=new Random();
        int length=random.nextInt(20)+1;
        StringBuilder builder=new StringBuilder();
        for(int i=0;i<length;i++){ 
            builder.append(content);
        }
        return builder.toString();
    }

工作完成分别在手机模拟器和平板模拟器上运行：

可以看到许多条新闻的标题，点击第一条新闻，会启动一个新的活动来显示新闻的内容

将程序 在平板模拟器上运行

同样点击第一条新闻：