基于Android平台开发，仿头条新闻app新闻分类分类列表实现（四）

标签：pic return String app 分类 private public Android void

1. 项目涉及到的技术点

列表控件RecyclerView的使用
调用API获取网络数据
Glide加载图片
Handler的使用
okhttp的使用

2. 代码实现过程

在上集中，已经使用TabLayout+ViewPager2把新闻分类滑动实现了，这集具体实现新闻列表

新闻布局fragment_tab_news.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.appcompat.widget.LinearLayoutCompat 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"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical"
    tools:context=".TabNewsFragment">

  <androidx.recyclerview.widget.RecyclerView
      android:id="@+id/recyclerView"
      android:layout_width="match_parent"
      app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
      tools:listitem="@layout/news_list_item"
      android:layout_height="match_parent"/>

</androidx.appcompat.widget.LinearLayoutCompat>

注意实现：app:layoutManager=“xxxxx” 两种设置方式：1. 在xml中直接设置 2. 通过代码设置，一定要设置，不然列表显示空白

RecyclerView需要的item布局news_list_item.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.appcompat.widget.LinearLayoutCompat xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">


    <androidx.appcompat.widget.LinearLayoutCompat
        android:layout_width="match_parent"
        android:layout_margin="10dp"
        android:layout_height="wrap_content">


        <ImageView
            android:id="@+id/thumbnail_pic_s"
            android:layout_width="110dp"
            android:src="@mipmap/ic_launcher"
            android:scaleType="centerCrop"
            android:layout_height="80dp"/>

        <androidx.appcompat.widget.LinearLayoutCompat
            android:layout_width="match_parent"
            android:layout_marginLeft="10dp"
            android:orientation="vertical"
            android:layout_height="match_parent">


            <TextView
                android:id="@+id/title"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:singleLine="true"
                android:textColor="#222222"
                android:text="国家市场监督管理总局拟规定：平台经营者应协助市场监管执法调查工作"/>


            <TextView
                android:id="@+id/author_name"
                android:layout_marginTop="10dp"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="新闻来源"/>


            <TextView
                android:id="@+id/date"
                android:layout_marginTop="10dp"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="新闻时间"/>

        </androidx.appcompat.widget.LinearLayoutCompat>

    </androidx.appcompat.widget.LinearLayoutCompat>

</androidx.appcompat.widget.LinearLayoutCompat>

适配器NewsListAdapter.java

public class NewsListAdapter extends RecyclerView.Adapter<NewsListAdapter.MyHolder> {

    private List<NewsInfo.ResultDTO.DataDTO> mDataDTOList = new ArrayList<>();
    private Context mContext;


    public void setListData(List<NewsInfo.ResultDTO.DataDTO> listData) {
        this.mDataDTOList = listData;
        //这句话不能少，一定要调用
        notifyDataSetChanged();
    }

    public NewsListAdapter(Context context) {
        this.mContext = context;

    }


    @NonNull
    @Override
    public MyHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {

        //加载布局文件
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.news_list_item, null);
        return new MyHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull MyHolder holder, int position) {
        //绑定数据
        NewsInfo.ResultDTO.DataDTO dataDTO = mDataDTOList.get(position);

        holder.author_name.setText("来源：" + dataDTO.getAuthor_name());
        holder.date.setText(dataDTO.getDate());
        holder.title.setText(dataDTO.getTitle());

        //加载图片
        Glide.with(mContext).load(dataDTO.getThumbnail_pic_s()).error(R.mipmap.img_error).into(holder.thumbnail_pic_s);


        //点击事件
        holder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (null != mOnItemClickListener) {
                    mOnItemClickListener.onItemClick(dataDTO, position);
                }
            }
        });

    }

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

    static class MyHolder extends RecyclerView.ViewHolder {
        ImageView thumbnail_pic_s;
        TextView author_name;
        TextView date;
        TextView title;


        public MyHolder(@NonNull View itemView) {
            super(itemView);
            thumbnail_pic_s = itemView.findViewById(R.id.thumbnail_pic_s);
            author_name = itemView.findViewById(R.id.author_name);
            date = itemView.findViewById(R.id.date);
            title = itemView.findViewById(R.id.title);
        }
    }


    private onItemClickListener mOnItemClickListener;


    public void setOnItemClickListener(onItemClickListener onItemClickListener) {
        mOnItemClickListener = onItemClickListener;
    }

    public interface onItemClickListener {
        void onItemClick(NewsInfo.ResultDTO.DataDTO dataDTO, int position);
    }

}

新闻数据实体NewsInfo.java

public class NewsInfo {

    private String reason;
    private ResultDTO result;
    private Integer error_code;

    public String getReason() {
        return reason;
    }

    public void setReason(String reason) {
        this.reason = reason;
    }

    public ResultDTO getResult() {
        return result;
    }

    public void setResult(ResultDTO result) {
        this.result = result;
    }

    public Integer getError_code() {
        return error_code;
    }

    public void setError_code(Integer error_code) {
        this.error_code = error_code;
    }

    public static class ResultDTO {
        private String stat;
        private List<DataDTO> data;
        private String page;
        private String pageSize;

        public String getStat() {
            return stat;
        }

        public void setStat(String stat) {
            this.stat = stat;
        }

        public List<DataDTO> getData() {
            return data;
        }

        public void setData(List<DataDTO> data) {
            this.data = data;
        }

        public String getPage() {
            return page;
        }

        public void setPage(String page) {
            this.page = page;
        }

        public String getPageSize() {
            return pageSize;
        }

        public void setPageSize(String pageSize) {
            this.pageSize = pageSize;
        }

        public static class DataDTO implements Serializable {
            private String uniquekey;
            private String title;
            private String date;
            private String category;
            private String author_name;
            private String url;
            private String thumbnail_pic_s;
            private String is_content;
            private String thumbnail_pic_s02;
            private String thumbnail_pic_s03;

            public String getUniquekey() {
                return uniquekey;
            }

            public void setUniquekey(String uniquekey) {
                this.uniquekey = uniquekey;
            }

            public String getTitle() {
                return title;
            }

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

            public String getDate() {
                return date;
            }

            public void setDate(String date) {
                this.date = date;
            }

            public String getCategory() {
                return category;
            }

            public void setCategory(String category) {
                this.category = category;
            }

            public String getAuthor_name() {
                return author_name;
            }

            public void setAuthor_name(String author_name) {
                this.author_name = author_name;
            }

            public String getUrl() {
                return url;
            }

            public void setUrl(String url) {
                this.url = url;
            }

            public String getThumbnail_pic_s() {
                return thumbnail_pic_s;
            }

            public void setThumbnail_pic_s(String thumbnail_pic_s) {
                this.thumbnail_pic_s = thumbnail_pic_s;
            }

            public String getIs_content() {
                return is_content;
            }

            public void setIs_content(String is_content) {
                this.is_content = is_content;
            }

            public String getThumbnail_pic_s02() {
                return thumbnail_pic_s02;
            }

            public void setThumbnail_pic_s02(String thumbnail_pic_s02) {
                this.thumbnail_pic_s02 = thumbnail_pic_s02;
            }

            public String getThumbnail_pic_s03() {
                return thumbnail_pic_s03;
            }

            public void setThumbnail_pic_s03(String thumbnail_pic_s03) {
                this.thumbnail_pic_s03 = thumbnail_pic_s03;
            }
        }
    }
}

TabNewsFragment.java页面

public class TabNewsFragment extends Fragment {

    //key自己去申请
    private String url = "http://v.juhe.cn/toutiao/index?key=xxxxxx&type=";

    private View rootView;
    private RecyclerView recyclerView;

    private NewsListAdapter mNewsListAdapter;


    private static final String ARG_PARAM = "title";
    private String title;


    private Handler mHandler = new Handler(Looper.myLooper()) {
        @Override
        public void handleMessage(@NonNull Message msg) {
            super.handleMessage(msg);
            if (msg.what == 100) {
                String data = (String) msg.obj;
                Log.d("------------------", "handleMessage: "+data);
                NewsInfo newsInfo = new Gson().fromJson(data, NewsInfo.class);
                if (newsInfo != null && newsInfo.getError_code() == 0) {
                    //逻辑处理
                    if (null != mNewsListAdapter) {
                        mNewsListAdapter.setListData(newsInfo.getResult().getData());
                    }
                } else {
                    Toast.makeText(getActivity(), "获取数据失败，请稍后重试", Toast.LENGTH_SHORT).show();
                }
            }
        }
    };


    public TabNewsFragment() {

    }

    public static TabNewsFragment newInstance(String param) {
        TabNewsFragment fragment = new TabNewsFragment();
        Bundle args = new Bundle();
        args.putString(ARG_PARAM, param);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            title = getArguments().getString(ARG_PARAM);
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        rootView = inflater.inflate(R.layout.fragment_tab_news, container, false);

        //初始化控件
        recyclerView = rootView.findViewById(R.id.recyclerView);


        return rootView;
    }

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

        //初始化适配器
        mNewsListAdapter = new NewsListAdapter(getActivity());
        //设置adapter
        recyclerView.setAdapter(mNewsListAdapter);

        //recyclerView列表点击事件
        mNewsListAdapter.setOnItemClickListener(new NewsListAdapter.onItemClickListener() {
            @Override
            public void onItemClick(NewsInfo.ResultDTO.DataDTO dataDTO, int position) {

                //跳转到详情页
                Intent intent = new Intent(getActivity(), NewsDetailsActivity.class);
                //传递对象的时候，该类一定要实现Serializable
                intent.putExtra("dataDTO", dataDTO);
                startActivity(intent);
            }
        });


        //获取数据
        getHttpData();
    }

    private void getHttpData() {

        //创建OkHttpClient对象
        OkHttpClient okHttpClient = new OkHttpClient();
        //构构造Request对象
        Request request = new Request.Builder()
                .url(url + title)
                .get()
                .build();

        //通过OkHttpClient和Request对象来构建Call对象
        Call call = okHttpClient.newCall(request);
        call.enqueue(new Callback() {
            @Override
            public void onFailure(@NonNull Call call, @NonNull IOException e) {
                Log.d("-----------------", "onFailure: " + e.toString());
            }

            @Override
            public void onResponse(@NonNull Call call, @NonNull Response response) throws IOException {
                String data = response.body().string();
                //                Log.d("----------------", "onResponse: "+data);

                //不能在耗时操作操作里面更新UI,那么需要使用Handler

                Message message = new Message();
                message.what = 100;
                message.obj = data;
                //发送
                mHandler.sendMessage(message);

            }


        });

    }
}

3. 运行效果图

在这里插入图片描述

相关视频教程在某站上面(
标签：pic,return,String,app,分类,private,public,Android,void
From： https://blog.csdn.net/jky_yihuangxing/article/details/140769377

基于Android平台开发，仿头条新闻app新闻分类分类列表实现（四）

1. 项目涉及到的技术点

2. 代码实现过程

3. 运行效果图

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