实体类和适配器的创建



以下为内容演示：代码和结果图

首先先做好页面布局（用线性布局的方法）

以下为做好的页面布局.

在创建一个item布局文件来显示商品信息.

这样我们的页面布局就写完了.

listview要创建实体类，所以建立对应的实体类.

 package com.example.bz0209.yukai.entity;

 /**
  * Created by Administrator on 2017/4/27.
  */

 public class Goods {
     private long id;
     private String name;
     private Integer amount;

     public Goods(String name, long id, Integer amount) {
         this.name = name;
         this.id = id;
         this.amount = amount;
     }

     public Goods(String name, Integer amount) {
         this.name = name;
         this.amount = amount;
     }

     public long getId() {
         return id;
     }

     public void setId(long id) {
         this.id = id;
     }

     public Integer getAmount() {
         return amount;
     }

     public void setAmount(Integer amount) {
         this.amount = amount;
     }

     public String getName() {
         return name;
     }

     public void setName(String name) {
         this.name = name;
     }

     @Override
     public String  toString() {
         return "Goods{" +
                 "id=" + id +
                 ", name='" + name + '\'' +
                 ", amount=" + amount +
                 '}';
     }
 }
  这样实体类就封装好了，接下来再创建适配器文件创建一个GoodsAdpter类
 "code" class="java">package com.example.bz0209.yukai;

 import android.content.Context;
 import android.support.annotation.NonNull;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.ArrayAdapter;
 import android.widget.ImageView;
 import android.widget.TextView;

 import java.util.List;

 /**
  * Created by Administrator on 2017/4/28.
  */

 public class Goodsadpter extends ArrayAdapter {
     private int resourceId;
     public Goodsadpter(Context context, int resource, List objects) {
         super(context, resource, objects);
         resourceId=resource;
     }

     @NonNull
     @Override
     public View getView(int position, View convertView, ViewGroup parent) {
         Goods goods = getItem(position);
         View view=null;
         ViewHolder viewHolder;
          if(convertView==null){
               view=LayoutInflater.from(getContext()).inflate(R.layout.item,null);
              viewHolder=new ViewHolder();
              viewHolder.tvId= (TextView) view.findViewById(R.id.tvId);
              viewHolder.tvName= (TextView) view.findViewById(R.id.tvName);
              viewHolder.tvAmount= (TextView) view.findViewById(R.id.tvAmount);
              viewHolder.ivUp= (ImageView) view.findViewById(R.id.ivUp);
              viewHolder.ivDown= (ImageView) view.findViewById(R.id.ivDown);
              viewHolder.ivDelete= (ImageView) view.findViewById(R.id.ivDelete);
              view.setTag(viewHolder);
          }else{
              view=convertView;
              viewHolder=(ViewHolder) view.getTag();
          }
         viewHolder.tvId.setText(goods.getId()+"");
         viewHolder.tvName.setText(goods.getName());
         viewHolder.tvAmount.setText(goods.getAmount()+"");
         return view;
     }
     class ViewHolder{
         TextView tvId;
         TextView tvName;
         TextView tvAmount;
         ImageView ivUp;
         ImageView ivDown;
         ImageView ivDelete;

     }

 }
 这样我们就把与listview匹配的goodsadpter创建好了.
 接下来就是对数据库（还未完善）的操作，基本就可以完成了