listView图文显示! 并且简单解决一下图片混乱问题

Posted 2022-12-13 粪乧

现在很多使用的应用中,都有一些图文兼并的消息展示,并且是列表形式实现的! 其中不乏有一些是使用的Listview来展示出来的. 今天简单的写了个demo再来回顾一下基础知识.
先来看看效果

现在来说说代码

这里我使用的是官方提供的Volley网络框架
在build中添加这个

dependencies 
 compile 'eu.the4thfloor.volley:com.android.volley:2015.05.28'
 

MainActivity.java

package com.xyb.newslistview;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.ListView;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;

public class MainActivity extends AppCompatActivity 
    private ListView listView; // 定义出listview
    private RequestQueue requestQueue; // 定义一个请求队列 使用volley包下的 官方产品棒棒哒!
    private String HTTPURL = "http://litchiapi.jstv.com/api/" +
            "GetFeeds?column=3&PageSize=20&pageIndex=1&val=100511D3BE5301280E0992C73A9DEC41";//请求的网址
    private ArrayList<NewsEntity.ParamzEntity.FeedsEntity.DataEntity> dataEntities
            = new ArrayList<>();// 坑爹的GsonFormat生成的 但是还真好用!
    private ListViewAdapter listViewAdapter; // listview必备是配置是也!

    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        requestQueue = Volley.newRequestQueue(this);
        initView();// 写个方法来初始化控件
        initData();// 写个方法来设置数据
    

    private void initData() 
        /**
         * 第一个是请求的网址
         * 第二个为请求成功的监听实现方法参数为解析到的String类型数据
         * 第三个是请求失败监听,那就把你失败后要执行的方法写在这里
         * **/
        StringRequest stringRequest = new StringRequest(HTTPURL, new Response.Listener<String>() 
            @Override
            public void onResponse(String response) 
                try 
                    // 原生的抠脚json解析,回顾回顾.....
                    JSONObject jsonObject = new JSONObject(response);
                    JSONObject object = jsonObject.getJSONObject("paramz");
                    JSONArray jsonArray = object.getJSONArray("feeds");
                    NewsEntity.ParamzEntity.FeedsEntity.DataEntity dataEntity;
                    for (int i = 0; i < jsonArray.length(); i++) 
                        // 将集合遍历额
                        JSONObject json = jsonArray.getJSONObject(i).getJSONObject("data");
                        String subject = json.getString("subject");
                        String summary = json.getString("summary");
                        String cover = "http://litchiapi.jstv.com" + json.getString("cover");
                        dataEntity = new NewsEntity.ParamzEntity.FeedsEntity.DataEntity(subject, summary, cover);
                        dataEntities.add(dataEntity);
                    
                    listViewAdapter.addNews(dataEntities);// 适配器中数据设置的方法将数据传递过去 notify一下

                 catch (JSONException e) 
                    e.printStackTrace();
                

            
        , new Response.ErrorListener() 
            @Override
            public void onErrorResponse(VolleyError error) 

            
        );
        requestQueue.add(stringRequest); // 请求需要加到队列中才能执行哦 这个是先执行哦 别看写在下面 哈哈

    

    /**
     * 初始化控件的方法
     **/
    private void initView() 
        listViewAdapter = new ListViewAdapter(this);
        listView = (ListView) findViewById(R.id.list);
        listView.setAdapter(listViewAdapter);
    

NewsEntity.java

package com.xyb.newslistview;
/*
                   _ooOoo_
                  o8888888o
                  88" . "88
                  (| -_- |)
                  O\\  =  /O
               ____/`---'\\____
             .'  \\\\|     |//  `.
            /  \\\\|||  :  |||//  \\
           /  _||||| -:- |||||-  \\
           |   | \\\\\\  -  /// |   |
           | \\_|  ''\\---/''  |   |
           \\  .-\\__  `-`  ___/-. /
         ___`. .'  /--.--\\  `. . __
      ."" '<  `.___\\_<|>_/___.'  >'"".
     | | :  `- \\`.;`\\ _ /`;.`/ - ` : | |
     \\  \\ `-.   \\_ __\\ /__ _/   .-` /  /
======`-.____`-.___\\_____/___.-`____.-'======
                   `=---='
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
         佛祖保佑       永无BUG
*/

import java.util.List;

/***
 * BY YanBinXie  AT 15/11/10 下午3:08
 */
public class NewsEntity 



    private String status;

    private ParamzEntity paramz;

    public void setStatus(String status) 
        this.status = status;
    

    public void setParamz(ParamzEntity paramz) 
        this.paramz = paramz;
    

    public String getStatus() 
        return status;
    

    public ParamzEntity getParamz() 
        return paramz;
    

    public static class ParamzEntity 
        private int PageIndex;
        private int PageSize;
        private int TotalCount;
        private int TotalPage;
        /**
         * id : 299058
         * oid : 288328
         * category : article
         * data : "subject":"工作人员套取新农合565元被降级","summary":"昨天记者获悉，驻马店市纪委通报4起涉医领域违纪违法典型案件。","cover":"/Attachs/Article/288328/65b28e724f3b4a65ae7bb3f5c97699ab_padmini.JPG","pic":"","format":"txt","changed":"2015-09-19 19:35:53"
         */

        private List<FeedsEntity> feeds;

        public void setPageIndex(int PageIndex) 
            this.PageIndex = PageIndex;
        

        public void setPageSize(int PageSize) 
            this.PageSize = PageSize;
        

        public void setTotalCount(int TotalCount) 
            this.TotalCount = TotalCount;
        

        public void setTotalPage(int TotalPage) 
            this.TotalPage = TotalPage;
        

        public void setFeeds(List<FeedsEntity> feeds) 
            this.feeds = feeds;
        

        public int getPageIndex() 
            return PageIndex;
        

        public int getPageSize() 
            return PageSize;
        

        public int getTotalCount() 
            return TotalCount;
        

        public int getTotalPage() 
            return TotalPage;
        

        public List<FeedsEntity> getFeeds() 
            return feeds;
        

        public static class FeedsEntity 
            private int id;
            private int oid;
            private String category;
            /**
             * subject : 工作人员套取新农合565元被降级
             * summary : 昨天记者获悉，驻马店市纪委通报4起涉医领域违纪违法典型案件。
             * cover : /Attachs/Article/288328/65b28e724f3b4a65ae7bb3f5c97699ab_padmini.JPG
             * pic :
             * format : txt
             * changed : 2015-09-19 19:35:53
             */



            private DataEntity data;

            public void setId(int id) 
                this.id = id;
            

            public void setOid(int oid) 
                this.oid = oid;
            

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

            public void setData(DataEntity data) 
                this.data = data;
            

            public int getId() 
                return id;
            

            public int getOid() 
                return oid;
            

            public String getCategory() 
                return category;
            

            public DataEntity getData() 
                return data;
            

            public static class DataEntity 
                private String subject;
                private String summary;
                private String cover;
                private String pic;
                private String format;
                private String changed;

                public DataEntity(String subject, String summary, String cover) 
                    this.subject = subject;
                    this.summary = summary;
                    this.cover = cover;
                

                public void setSubject(String subject) 
                    this.subject = subject;
                

                public void setSummary(String summary) 
                    this.summary = summary;
                

                public void setCover(String cover) 
                    this.cover = cover;
                

                public void setPic(String pic) 
                    this.pic = pic;
                

                public void setFormat(String format) 
                    this.format = format;
                

                public void setChanged(String changed) 
                    this.changed = changed;
                

                public String getSubject() 
                    return subject;
                

                public String getSummary() 
                    return summary;
                

                public String getCover() 
                    return cover;
                

                public String getPic() 
                    return pic;
                

                public String getFormat() 
                    return format;
                

                public String getChanged() 
                    return changed;
                
            
        
    

ListViewAdapter.java

package com.xyb.newslistview;
/*
                   _ooOoo_
                  o8888888o
                  88" . "88
                  (| -_- |)
                  O\\  =  /O
               ____/`---'\\____
             .'  \\\\|     |//  `.
            /  \\\\|||  :  |||//  \\
           /  _||||| -:- |||||-  \\
           |   | \\\\\\  -  /// |   |
           | \\_|  ''\\---/''  |   |
           \\  .-\\__  `-`  ___/-. /
         ___`. .'  /--.--\\  `. . __
      ."" '<  `.___\\_<|>_/___.'  >'"".
     | | :  `- \\`.;`\\ _ /`;.`/ - ` : | |
     \\  \\ `-.   \\_ __\\ /__ _/   .-` /  /
======`-.____`-.___\\_____/___.-`____.-'======
                   `=---='
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
         佛祖保佑       永无BUG
*/

import android.content.Context;
import android.graphics.Bitmap;
import android.support.v4.util.LruCache;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import com.android.volley.RequestQueue;
import com.android.volley.toolbox.ImageLoader;
import com.android.volley.toolbox.NetworkImageView;
import com.android.volley.toolbox.Volley;

import java.util.ArrayList;

/***
 * BY YanBinXie  AT 15/11/10 下午3:06
 */
public class ListViewAdapter extends BaseAdapter 
    private Context context;
    private ArrayList<NewsEntity.ParamzEntity.FeedsEntity.DataEntity> newsEntities;

    private NetworkImageView iv;
    private ImageLoader imageLoader;

    public ListViewAdapter(Context context) 
        this.context = context;
        RequestQueue queue = Volley.newRequestQueue(context);
        imageLoader = new ImageLoader(queue, new ImageLoader.ImageCache() 
            int maxMemory = (int) Runtime.getRuntime().maxMemory();
            int cacheSize = maxMemory / 8; // imageLoader 最大缓存哦哦
            private LruCache<String, Bitmap> mCache = new LruCache<>(cacheSize);

            @Override
            public Bitmap getBitmap(String url) 
                return mCache.get(url);
            

            @Override
            public void putBitmap(String url, Bitmap bitmap) 
                mCache.put(url, bitmap);
            
        );
    

    public void addNews(ArrayList<NewsEntity.ParamzEntity.FeedsEntity.DataEntity> newsEntities) 
        this.newsEntities = newsEntities;
        notifyDataSetChanged();

    

    @Override
    public int getCount() 
        return newsEntities != null && newsEntities.size() > 0 ? newsEntities.size() : 0;
    

    @Override
    public Object getItem(int position) 
        return newsEntities != null && newsEntities.size() > 0 ? newsEntities.get(position) : null;

    

    @Override
    public long getItemId(int position) 
        return newsEntities != null && newsEntities.size() > 0 ? position : 0;
    

    @Override
    public View getView(int position, View convertView, ViewGroup parent) 
        View view;
        /**
         * 这是一种实现方法 但是我感觉使用ViewHolder的方法比较好,这里偷懒了,,
         * */
        TextView title,summary;
        if (convertView == null) 
            view = LayoutInflater.from(context).inflate(R.layout.list_item, null);
         else 
            view = convertView;
        
        iv = (NetworkImageView) view.findViewById(R.id.iv);
        summary = (TextView) view.findViewById(R.id.summary);
        title = (TextView) view.findViewById(R.id.title);
        summary.setText(newsEntities.get(position).getSummary());
        title.setText(newsEntities.get(position).getSubject());
        iv.setDefaultImageResId(R.mipmap.ic_launcher);
        iv.setErrorImageResId(R.mipmap.ic_launcher);
        iv.setImageUrl(newsEntities.get(position).getCover(), imageLoader);

        return view;
    

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="新闻listview" />

    <ListView
        android:id="@+id/list"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@+id/text" />
</RelativeLayout>

list_item.xml

<?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="100dp">

    <com.android.volley.toolbox.NetworkImageView
        android:id="@+id/iv"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:layout_centerVertical="true"
        android:padding="5dp"/>

    <TextView
        android:id="@+id/title"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:layout_toRightOf="@id/iv"
        android:gravity="center_vertical"
        android:textSize="14sp"
        android:textStyle="bold" />

    <TextView
        android:id="@+id/summary"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/title"
        android:layout_marginTop="8dp"
        android:layout_toRightOf="@id/iv"
        android:textSize="12sp" />

</RelativeLayout>

代码就这些 大牛勿喷. 同时大家可以使用一些简单易用的图片加载方法,但是要解决图片混乱好象有点繁琐,以后继续学学! UIL,Picasso,Fresco,Glide 等等很多 图片加载库.

还有可能大家学的抠脚json解析有点坑爹效率低,那么我推荐大家使用Gson, fastjson(据说是最快的).下面我简单记录一下使用方法.

Gson :
在build中添加这个

dependencies 
    compile 'com.google.code.gson:gson:2.2.4'
 

代码中
这个为实体类的最外层类名 与类对象 可以一层一层的扒扒!

Gson gson = new Gson();
NewsEntity newsEntity = gson.fromJson(response, NewsEntity.class);

只需要这两行就完事了

FastJson :
添加

    compile 'com.alibaba:fastjson:1.2.7'

代码使用 说明同上!

NewsEntity newsEntity = JSON.parseObject(response,NewsEntity.class);

就这一行 是不是感觉好方便..哈哈 但是限制挺多的 json数据必须规范才行哦 !哈哈
互相交流 大牛勿喷!

代码下载地址! 点我啊