listView Adapter 的应用

1.新浪微博运行效果图

2.主要代码

布局代码list.xml：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" 
    android:orientation="horizontal">
    <ImageView 
        android:id="@+id/Iv"
        android:layout_marginTop="10dp"
        android:layout_marginLeft="10dp"
        android:layout_width="50sp"
        android:layout_height="50sp"/>
<LinearLayout 
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
   android:orientation="vertical"
   android:layout_marginLeft="20sp">
   <LinearLayout 
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:orientation="horizontal">
       <TextView 
           android:id="@+id/Name"
           android:layout_width="wrap_content"
           android:layout_height="wrap_content"
           android:text="姓名"
           android:layout_weight="5"
           android:textSize="20sp"/>
       <TextView 
           android:id="@+id/Time"
           android:layout_width="wrap_content"
           android:layout_height="wrap_content"
           android:layout_weight="1"
           android:text="1分钟前"/>
   </LinearLayout>
   <TextView 
       android:id="@+id/Contents"
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:text="测试内容区域"
       android:layout_marginTop="5dp"/>
</LinearLayout>
</LinearLayout>

2. main_activity

public class MainActivity extends Activity {
private ListView listView;
private MyAdapter adapter;
private List<Information> list;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setData();//数据源
        initView();
    }
private void initView() {
// 初始化控件
listView=(ListView) findViewById(R.id.Lv);
listView.setAdapter(adapter);  //绑定适配器
}
private void setData() {
// 设置数据源
list=new ArrayList<Information>();
list.add(new Information(R.drawable.a,"xiaobai","2015-5-05","今天的天气不错"));

adapter=new MyAdapter(list, MainActivity.this);
}           
}

3.adapter

public class MyAdapter extends BaseAdapter {
private List<Information> list;
private Context mContext;
private LayoutInflater mInflater;
//定义构造方法
public MyAdapter(List<Information> list, Context mContext) {
super();
this.list = list;
this.mContext = mContext;
}

public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder=null;
if(convertView==null){
convertView=mInflater.from(mContext).inflate(R.layout.listview_item,null);
holder=new ViewHolder();
//实例化控件
holder.Image=(ImageView)convertView.findViewById(R.id.Iv);
holder.Name=(TextView)convertView.findViewById(R.id.Name);
holder.Time=(TextView)convertView.findViewById(R.id.Time);
holder.Contents=(TextView)convertView.findViewById(R.id.Contents);
convertView.setTag(holder); //设置setTag使得程序得以优化
}else{
holder=(ViewHolder) convertView.getTag();
}
//给控件赋值
holder.Image.setBackgroundResource(list.get(position).getImgId());
holder.Name.setText(list.get(position).getName());
holder.Time.setText(list.get(position).getDate());
holder.Contents.setText(list.get(position).getContent());
return convertView;
}

class ViewHolder{
ImageView Image;
TextView  Name;
TextView  Time;
TextView  Contents;
}
}