设计一个商品展示案列

来源：互联网发布：php防止ajax重复提交编辑：程序博客网时间：2024/05/16 06:41

首先呢，要和大家说明一件令我挺尴尬的事情。那就是这篇博文里的代码我写了两遍，至于原因，肯定不是因为我向多加巩固，而是我在量一片电脑上原先敲的代码因为我自己的原因，保存不当导致打不开了....所以现在这篇博文里的代码其实是第二次敲得......

好了，这次我们设计的是一个商品展示案例。要求我们开发一个购物车，需要将购物车中的商品以列表的形式展示，并且还需要对购物车中的商品进行增删改查操作。本次功能的实现需要使用ListView和数据库。

下面给大家提供部分代码：

activity_main.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:layout_margin="8dp"
tools:context="cn.edu.bzu.shopshow.MainActivity">

<LinearLayout
android:id="@+id/addLL"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">

<EditText
android:layout_width="0dp"
android:layout_height="wrap_content"
android:inputType="textPersonName"
android:hint="商品名称"
android:layout_weight="1"
android:id="@+id/nameET" />

<EditText
android:layout_width="0dp"
android:layout_height="wrap_content"
android:inputType="number"
android:hint="金额"
android:layout_weight="1"
android:id="@+id/balanceET" />

<ImageView
android:onClick="add"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@android:drawable/ic_input_add"
android:id="@+id/addIV" />
</LinearLayout>

<ListView
android:id="@+id/accountLV"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="@+id/addLL">
</ListView>
</LinearLayout>

item.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">

<TextView
android:text="1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/tvId"
android:textSize="20sp"
android:layout_weight="1" />
<TextView
android:text="商品名称"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/tvName"
android:textSize="20sp"
android:layout_weight="2" />
<TextView
android:text="金额"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/tvAmount"
android:textSize="20sp"
android:layout_weight="2" />
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<ImageView
android:id="@+id/ivUp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@android:drawable/arrow_up_float"/>
<ImageView
android:id="@+id/ivDown"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@android:drawable/arrow_down_float"/>
</LinearLayout>
<ImageView
android:layout_width="25dp"
android:layout_height="25dp"
android:src="@android:drawable/ic_menu_delete"/>

</LinearLayout>

dao//MyHelper.java

package cn.edu.bzu.shopshow.dao;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.provider.Settings;

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

public class MyHelper extends SQLiteOpenHelper {

public MyHelper(Context context) {
super(context,"itcast.db",null,2);
}

@Override
public void onCreate(SQLiteDatabase db) {
System.out.println("onCreate");
db.execSQL("CREATE TABLE account(_id INTEGER PRIMARY KEY AUTOINCREMENT,name VARCHAR(20),balance INTEGER)");
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
System.out.println("onUpgrade");

}
}

GoodsDao：

package com.example.administrator.shopshowdemo.dao;import android.content.ContentValues;import android.content.Context;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import com.example.administrator.shopshowdemo.db.DBHelper;import com.example.administrator.shopshowdemo.entity.Goods;import java.util.ArrayList;import java.util.List;/** * Created by Administrator on 2017/4/27. */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 valuse= new ContentValues();        valuse.put("name",goods.getName());        valuse.put("amount",goods.getAmount());        long id=sqLiteDatabase.insert("gooods",null,valuse);        goods.setId(id);        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 valuse= new ContentValues();        valuse.put("name",goods.getName());        valuse.put("amount",goods.getAmount());        int count=sqLiteDatabase.update("goods",valuse,"_id+?",new String[]{goods.getId()+""});        sqLiteDatabase.close();        return count;    }    public List<Goods> queryAll(){        List<Goods> goodsList=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(id,name,amount);            goodsList.add(goods);        }        cursor.close();        sqLiteDatabase.close();        return goodsList;    }}

这就是我所编写的代码，有一些乱，大家请忽视我...

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