listView图文显示! 并且简单解决一下图片混乱问题

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