首先我们先看一下要模拟的界面
我们主要实现的就是ListView解析json文件中的数据，UI布局很简单不做赘述。 这里我们需要一个服务器来实现数据的动态更新， 这里我们用到的是Tomcat8.0。 首先我们把需要解析的json文件放置到Tomcat的webapp文件下的ROOT里面，方便我们解析。
首先我们创建一个JsonParse类用来解析json文件：
package cn.edu.bzu.myapplication.Tools;import com.google.gson.Gson;import com.google.gson.reflect.TypeToken;import java.lang.reflect.Type;import java.util.List;import cn.edu.bzu.myapplication.entity.NewsInfo;/** * Created by Becauseshy on 2017/5/18. */public class JsonParse { public static List<NewsInfo> getNewInfo(String json){ Gson gson=new Gson(); Type listType=new TypeToken<List<NewsInfo>>(){ }.getType(); List<NewsInfo> newsInfos=gson.fromJson(json,listType); return newsInfos; }}
创建json文件的实体类：
package cn.edu.bzu.myapplication.entity;/** * Created by Becauseshy on 2017/5/17. */public class NewsInfo { private String iconPath; private String title; private String description; private int type; private long comment; public String getIconPath() { return iconPath; } public void setIconPath(String iconPath) { this.iconPath = iconPath; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public String getDescription() { return description; } public void setDescription(String description) { this.description = description; } public int getType() { return type; } public void setType(int type) { this.type = type; } public long getComment() { return comment; } public void setComment(long comment) { this.comment = comment; }}
activity_main.xml：
<?xml version="1.0" encoding="utf-8"?><LinearLayout 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" tools:context=".MainActivity" android:orientation="vertical"> <FrameLayout android:layout_width="match_parent" android:layout_height="match_parent"> <LinearLayout android:id="@+id/loading" android:layout_width="match_parent" android:layout_height="match_parent" android:gravity="center" android:orientation="vertical" android:visibility="invisible"> <ProgressBar android:layout_width="wrap_content" android:layout_height="wrap_content" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="正在加载信息..." /> </LinearLayout> <ListView android:id="@+id/lv_news" android:layout_width="match_parent" android:layout_height="match_parent" /> </FrameLayout></LinearLayout>
item的布局文件：
<?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="65dp"> <com.loopj.android.image.SmartImageView android:id="@+id/siv_icon" android:layout_width="80dp" android:layout_height="60dp" android:scaleType="centerCrop" android:src="@mipmap/ic_launcher" android:layout_alignParentLeft="true" android:layout_alignParentStart="true"></com.loopj.android.image.SmartImageView> <TextView android:id="@+id/tv_title" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginLeft="5dp" android:layout_marginTop="10dp" android:layout_toRightOf="@id/siv_icon" android:ellipsize="end" android:maxLength="20" android:singleLine="true" android:text="我是标题" android:textColor="#000000" android:textSize="18sp" /> <TextView android:id="@+id/tv_description" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@id/tv_title" android:layout_marginLeft="5dp" android:layout_marginTop="5dp" android:layout_toRightOf="@id/siv_icon" android:ellipsize="end" android:maxLength="16" android:maxLines="1" android:text="我是描述" android:textColor="#99000000" android:textSize="14sp" /> <TextView android:id="@+id/tv_type" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:layout_alignParentRight="true" android:layout_marginBottom="5dp" android:layout_marginRight="10dp" android:text="评论" android:textColor="#99000000" android:textSize="12sp" /></RelativeLayout>
适配器代码：
package cn.edu.bzu.myapplication.adapter;/** * Created by Becauseshy on 2017/5/17. */import android.content.Context;import android.graphics.Color;import android.support.annotation.NonNull;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.ArrayAdapter;import android.widget.TextView;import com.loopj.android.image.SmartImageView;import java.util.List;import cn.edu.bzu.myapplication.R;import cn.edu.bzu.myapplication.entity.NewsInfo;public class NewAdapter extends ArrayAdapter<NewsInfo>{private int resourceID; public NewAdapter(Context context, int resource, List<NewsInfo> objects) { super(context, resource, objects); resourceID=resource; } @Override public View getView(int position, View convertView, ViewGroup parent) { NewsInfo fruit=getItem(position); View view; ViewHolder viewHolder; if(convertView==null){ view=LayoutInflater.from(getContext()).inflate(resourceID,null); viewHolder=new ViewHolder(); viewHolder.siv=(SmartImageView)view.findViewById(R.id.siv_icon); viewHolder.tv_title=(TextView)view.findViewById(R.id.tv_title); viewHolder.tv_description=(TextView)view.findViewById(R.id.tv_description); viewHolder.tv_type=(TextView)view.findViewById(R.id.tv_type); view.setTag(viewHolder); }else{ view=convertView; viewHolder= (ViewHolder) view.getTag(); } viewHolder.siv.setImageUrl(fruit.getIconPath(),R.drawable.a,R.drawable.ic_launcher); viewHolder.tv_title.setText(fruit.getTitle()); viewHolder.tv_description.setText(fruit.getDescription()); int type=fruit.getType(); switch (type){ case 1: viewHolder.tv_type.setText("评论："+fruit.getComment()); viewHolder.tv_type.setTextColor(Color.BLUE); break; case 2: viewHolder.tv_type.setText("专题"); viewHolder.tv_type.setTextColor(Color.BLACK); break; case 3: viewHolder.tv_type.setText("LIVE"); viewHolder.tv_type.setTextColor(Color.RED); break; } return view; } class ViewHolder{ SmartImageView siv; TextView tv_title; TextView tv_description; TextView tv_type; }}
MainActivity实现代码：
package cn.edu.bzu.myapplication;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.LinearLayout;import android.widget.ListView;import android.widget.Toast;import com.loopj.android.http.AsyncHttpClient;import com.loopj.android.http.AsyncHttpResponseHandler;import java.io.UnsupportedEncodingException;import java.util.ArrayList;import java.util.List;import cn.edu.bzu.myapplication.Tools.JsonParse;import cn.edu.bzu.myapplication.adapter.NewAdapter;import cn.edu.bzu.myapplication.entity.NewsInfo;import cn.edu.bzu.myapplication.model.Fruit;public class MainActivity extends AppCompatActivity { private ListView Iv_news; private NewAdapter newAdapter; private List<NewsInfo> newInfos; private LinearLayout loading; private JsonParse jsonParse; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Iv_news= (ListView) findViewById(R.id.lv_news); newAdapter =new NewAdapter(this,R.layout.news_item,newInfos); loading= (LinearLayout) findViewById(R.id.loading); prepareData(); } private void prepareData() { //fruitList=new ArrayList<>(); //Fruit apple=new Fruit("Apple",R.drawable.apple_pic); // fruitList.add(apple); AsyncHttpClient asyncHttpClient=new AsyncHttpClient(); asyncHttpClient.get(getString(R.string.serverurl), new AsyncHttpResponseHandler() { @Override public void onSuccess(int i, cz.msebera.android.httpclient.Header[] headers, byte[] bytes) { try { String json=new String(bytes,"utf-8"); newInfos=jsonParse.getNewInfo(json); if(newInfos==null){ Toast.makeText(MainActivity.this,"解析失败",Toast.LENGTH_SHORT).show(); } else { loading.setVisibility(View.INVISIBLE); Iv_news.setAdapter(newAdapter); } } catch (UnsupportedEncodingException e) { e.printStackTrace(); } } @Override public void onFailure(int i, cz.msebera.android.httpclient.Header[] headers, byte[] bytes, Throwable throwable) { Toast.makeText(MainActivity.this,"请求失败",Toast.LENGTH_SHORT).show(); } }); }}
在values文件加下的String.xml文件中添加：
<string name=”serverurl”>http://172.16.26.58:8080/newInfo.xml</string>
最后一定不要忘了添加网络访问权限， 这很重要， 好多同学都犯了这个错误、
这样基本功能就实现了。
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。
然后拍一些美得想哭的照片，留给老年的自己。
