Android————一个简单的新闻面板_安卓实现一个新闻页面

效果图

功能实现：
使用Fragment碎片实现横竖两个碎片，达到一个简易新闻界面的效果
效果图如下：

第一步：建一个实体类News

public class News {
    private String Title;//标题
    private String Content;//内容
    public News(String Title, String Content){
        this.Title = Title;
        this.Content = Content;
    }
    public String getTitle() {
        return Title;
    }
    public String getContent() {
        return Content;
    }
}
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第二步：新建一个活动NewsContent

public class NewsContent extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_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);
    }
    public static void ActionStart(Context context, String newsTitle, String newsContent ){
        Intent intent = new Intent(context,NewsContent.class);
        intent.putExtra("news_title",newsTitle);
        intent.putExtra("news_content",newsContent);
        context.startActivity(intent);
    }
}
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布局文件

<LinearLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"   
    android:layout_width="match_parent"    
    android:layout_height="match_parent">   
    <fragment       
        android:id="@+id/news_content_fragment"
        android:name="com.example.newsinterface.NewsContentFragment"
        android:layout_width="match_parent"      
        android:layout_height="match_parent"/>       
</LinearLayout>
<font size =4  color = "#ff0000">第三步：建立一个子布局content_show,用做新闻内容布局</font>
代码如下：
<?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">

    <LinearLayout
        android:id="@+id/liner_layout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:visibility="invisible">

        <TextView
            android:id="@+id/NewsTitle"
            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/NewsContent"
            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>
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第四步：建立NewsContentFragment和NewsTitleFragment用做新闻内容布局

两个都继承Fragment,其中NewsTitleFragment建立了一个RecyclerView内部类用作适配器

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.content_show,container,false);
        return view;
    }
    public void Refresh(String newsTitle,String newsContent){
    
        View visibilityLayout = view.findViewById(R.id.liner_layout);
        visibilityLayout.setVisibility(View.VISIBLE);//显示
        TextView newsTitleText = (TextView) view.findViewById(R.id.NewsTitle);
        TextView newsContentText = (TextView) view.findViewById(R.id.NewsContent);
        newsTitleText.setText(newsTitle);
        newsContentText.setText(newsContent);
    }
}

NewsTitleFragment代码如下：

public class NewsTitleFragment extends Fragment {
    private boolean flag;
    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.news_title, container, false);
        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;
    }
    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        if (getActivity().findViewById(R.id.news_content_fragment) != null)
            flag = true;
        else
            flag = false;
    }
    private List<News> getNews() {
        List<News> newsList = new ArrayList<News>();
        for (int i = 0; i <= 50; ++i) {
            News news = new News("This is news title " + i, "This is news Content " + i + ". ");
            newsList.add(news);
        }
        return newsList;
    }
    private String getRandomLengthContent(String s) {
        Random random = new Random();
        int length = random.nextInt(20) + 1;
        StringBuilder builder = new StringBuilder();
        for (int i = 0; i < length; ++i) {
            builder.append(s);
        }
        return builder.toString();
    }
    class NewsAdapter extends RecyclerView.Adapter<NewsAdapter.ViewHolder> {
        private List<News> mNewsList;
        public NewsAdapter(List<News> newsList) {
            mNewsList = newsList;
        }
        @NonNull
        @Override
        public 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 view) {
                    News news = mNewsList.get(holder.getAdapterPosition());
                    if (flag) {
                        NewsContentFragment newsContentFragment =
                                (NewsContentFragment) getFragmentManager().findFragmentById(R.id.news_content_fragment);
                        newsContentFragment.Refresh(news.getTitle(), news.getContent());
                        news.getContent();
                    } 
                    else 
                    {
                        NewsContent.ActionStart(view.getContext(), news.getTitle(), news.getContent());
                    }
                }
            });
            return holder;
        }
        @Override
        public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
            News news = mNewsList.get(position);
            holder.newsTitleText.setText(news.getTitle());
        }
        @Override
        public int getItemCount() {
            return mNewsList.size();
        }
        class ViewHolder extends RecyclerView.ViewHolder {
            TextView newsTitleText;
            public ViewHolder(@NonNull View itemView) {
                super(itemView);
                newsTitleText = (TextView) itemView.findViewById(R.id.news_title);
              }
        }
    }
}
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最后建立一个适用于RecyclerView的子布局命名为new_item

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/news_title_recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"  />
        </LinearLayout>
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