1. 训练目标
1) 掌握ListView 控件的使用
2) 理解Adapter 的作用并掌握自定义FruitAdapter 的使用方式
2.开发步骤
1）自定义适配器MyAdapter
package cn.edu.bzu.adapter;
import java.util.List;
import cn.edu.bzu.entity.Information;
import cn.edu.bzu.weibo_looking.R;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
/**
* 自定义Adapter实现listView的显示
* @author monster
* @date : 2015-04-28
*/
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;
}
@Override
public int getCount() {
return list.size();
}
@Override
public Object getItem(int position) {
return list.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
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); //布局转换成视图
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;
}
}
2)MainActivity的编写
package cn.edu.bzu.weibo_looking;
import java.util.ArrayList;
import java.util.List;
import cn.edu.bzu.adapter.MyAdapter;
import cn.edu.bzu.entity.Information;
import android.os.Bundle;
import android.widget.ListView;
import android.app.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.img1,"小白","2015-04-06","Lalala德玛西亚"));
list.add(new Information(R.drawable.img2, "小明", "2015-05-06", "今天上班好累"));
list.add(new Information(R.drawable.img3,"小红","2015-05-06","交个朋友吧"));
list.add(new Information(R.drawable.img4,"小g","2015-05-06","快期中考试了，看来得好好学习了！"));
list.add(new Information(R.drawable.img5,"大白","2015-05-06","妹子，约嘛~"));
list.add(new Information(R.drawable.img6, "小Q", "2015-05-06", "啦啦啦"));
list.add(new Information(R.drawable.img7, "涂涂", "2015-05-06", "好想吃炸小丸子哦"));
list.add(new Information(R.drawable.img8, "小丸子", "2015-05-06", "为什么要吃我"));
adapter=new MyAdapter(list, MainActivity.this);
}
}