Android实现商品展示效果

这篇文章主要为大家详细介绍了Android实现商品展示效果，具有一定的参考价值，感兴趣的小伙伴们可以参考一下

一、创建手机界面布局

创建一个activity_main.xml文件代码如下：

效果图如下：

二、创建一个存储展示的xml文件

创建一个名为item.xml的布局文件，代码如下：

三、创建数据库

在com.example.bz0209.shopshowdemo 的包下创建一个名为db的包，并在该包下定义一个dbHelper类继承自SQLiteOpenHelper，创建数据库代码如下：

 package com.example.bz0209.shopshowdemo.db; import android.content.Context; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; /** * Created by Administrator on 2017/4/28. */ public class DBHelper extends SQLiteOpenHelper{ public static final String CREATE_GOODS="create table goods(_id integer primary key autoincrement,name varchar(20),amount integer)"; public DBHelper(Context context,int version){ super(context,"goods.db",null,version); } @Override public void onCreate(SQLiteDatabase db) { db.execSQL(CREATE_GOODS); } @Override public void onUpgrade(SQLiteDatabase db,int oldVersion,int newVersion) { } }

四、创建GoodsAdapter类

为了操作数据库方便，创建一个GoodsAdapter类。因此需要在com.example.bz0209.shopshowdemo 的包下创建一个名为entity的包，然后在com.example.bz0209.shopshowdemo.entityd的包下定义一个GoodsAdapter类，代码如下：

 package com.example.bz0209.shopshowdemo; 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 com.example.bz0209.shopshowdemo.entity.Goods; import java.util.List; /** * Created by Administrator on 2017/4/27. */ public class GoodsAdapter extends ArrayAdapter{ private int resounceId; public GoodsAdapter(Context context, int resource, List objects) { super(context, resource, objects); resounceId=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(resounceId,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.etAmount); 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; } }

五、创建数据操作逻辑类

在com.example.bz0209.shopshowdemo 的包下创建一个名为dao的包，并创建一个名为GoodsDao的类，用于操作数据。代码如下：

 public class GoodsDao { private DBHelper dbHelper; public GoodsDao(Context context){ dbHelper=new DBHelper(context,1); } public void add(Goods goods){ SQLiteDatabase sqLiteDatabase=dbHelper.getWritableDatabase(); ContentValues values=new ContentValues(); values.put("name",goods.getName()); values.put("amount",goods.getAmount()); sqLiteDatabase.insert("goods",null,values); sqLiteDatabase.close(); } public int delete(long id){ SQLiteDatabase sqLiteDatabase=dbHelper.getWritableDatabase(); int count=sqLiteDatabase.delete("goods","id=?",new String[]{id+""}); sqLiteDatabase.close(); return count; } public int update(Goods goods){ SQLiteDatabase sqLiteDatabase=dbHelper.getWritableDatabase(); ContentValues values=new ContentValues(); values.put("name",goods.getName()); values.put("amount",goods.getAmount()); int count=sqLiteDatabase.update("goods",values,"id=?",new String[]{goods.getId()+""}); sqLiteDatabase.close(); return count; } public List queryAll(){ ListgoodsList=new ArrayList<>(); SQLiteDatabase sqLiteDatabase=dbHelper.getReadableDatabase(); Cursor cursor=sqLiteDatabase.query("goods",null,null,null,null,null,"amount desc"); while (cursor.moveToNext()){ long id=cursor.getLong(cursor.getColumnIndex("_id")); String name=cursor.getString(cursor.getColumnIndex("name")); int amount=cursor.getInt(cursor.getColumnIndex("amount")); Goods goods=new Goods(name,amount); goodsList.add(goods); } cursor.close(); sqLiteDatabase.close(); return goodsList; } }

六、编写界面交互代码

数据库操作完成后，需要界面与数据库进行交互，用于实现将数据库中的数据以ListView的形式展现在界面上具体代码如下：

 package com.example.bz0209.shopshowdemo; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.EditText; import android.widget.ListView; import com.example.bz0209.shopshowdemo.dao.GoodsDao; import com.example.bz0209.shopshowdemo.entity.Goods; import java.util.List; public class activity_main extends AppCompatActivity { private EditText etName; private EditText etAmount; private ListView lvGoods; private GoodsAdapter goodsAdapter; private GoodsDao goodsDao; private ListgoodsList; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); etName=(EditText)findViewById(R.id.etName); etAmount=(EditText)findViewById(R.id.etAmount); lvGoods=(ListView)findViewById(R.id.lvGoods); goodsDao=new GoodsDao(this); goodsList=goodsDao.queryAll(); goodsAdapter=new GoodsAdapter(this,R.layout.item,goodsList); lvGoods.setAdapter(goodsAdapter); } public void addGoods(View view){ String name=etName.getText().toString(); String amount=etAmount.getText().toString(); Goods goods=new Goods(name,amount.equals("")?0:Integer.parseInt(amount)); goodsDao.add(goods); } }

七、完成后的结果展示

（1）创建起数据库的图为：