大学安卓课程，实现模拟商店的构建！

<?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:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:layout_margin="8dp"
tools:context="com.example.renxiaohen.gz_shop.MainActivity">
<LinearLayout
android:id="@+id/addLL"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<EditText
android:id="@+id/etname"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:hint="商品名称"
android:inputType="textPersonName"/>
<EditText
android:id="@+id/etamount"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:hint="商品金额"
android:inputType="number"/>
<ImageView
android:id="@+id/ivadd"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="addGoods"
<
4000
span style="color:#008000;">android:src="@android:drawable/ic_input_add"
/>
</LinearLayout>
<ListView
android:id="@+id/lvGoods"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
</ListView>

</LinearLayout>

<?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="wrap_content"
android:orientation="horizontal">
<TextView
android:id="@+id/tvId"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="1"
android:textSize="20sp"
/>
<TextView
android:id="@+id/tvname"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="2"
android:gravity="left"
android:text="商品名称"
android:textSize="20sp"
/>
<TextView
android:id="@+id/tvamount"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="2"
android:gravity="left"
android:text="商品金额"
android:textSize="20sp"
/>

<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical">

<ImageView
android:id="@+id/ivup"
android:layout_width="10dp"
android:layout_height="10dp"
android:layout_marginBottom="2dp"
android:src="@android:drawable/arrow_up_float" />

<ImageView
android:id="@+id/ivdown"
android:layout_width="10dp"
android:layout_height="10dp"
android:layout_marginBottom="2dp"
android:src="@android:drawable/arrow_down_float" />
</LinearLayout>

<ImageView
android:id="@+id/ivdelete"
android:layout_width="25dp"
android:layout_height="25dp"
android:src="@android:drawable/ic_menu_delete"/>

</LinearLayout>

package com.example.renxiaohen.gz_shop.ently;

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

public class Goods {
private Long id;
private String name;
private Integer Amount;

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

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

public Long getId() {
return id;
}

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

public String getName() {
<
e00a
span style="color:#000080;">return name;
}

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

public Integer getAmount() {
return Amount;
}

public void setAmount(Integer amount) {
Amount = amount;
}

@Override
public String toString() {
return "Goods{" +
"id=" + id +
", name='" + name + '\'' +
", Amount=" + Amount +
'}';
}
}

package com.example.renxiaohen.gz_shop.dao;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;

import com.example.renxiaohen.gz_shop.db.DBHelper;
import com.example.renxiaohen.gz_shop.ently.Goods;

import java.util.ArrayList;
import java.util.List;

/**
* Created by renxiaohen on 2017/4/29.
*/

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("num",goods.getAmount());
long id=sqLiteDatabase.insert("goods",null,values);
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 values=new ContentValues();
values.put("name",goods.getName());
values.put("num",goods.getAmount());
int count=sqLiteDatabase.update("goods",values,"_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;
}
}

package com.example.renxiaohen.gz_shop;

import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.support.annotation.LayoutRes;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
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.renxiaohen.gz_shop.dao.Goodsdao;
import com.example.renxiaohen.gz_shop.ently.Goods;

import java.util.List;

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

public class GoodsAdapter extends ArrayAdapter<Goods>{
private int resouncelId;
private Goodsdao goodsdao;
private List<Goods> goodsList;
public GoodsAdapter(@NonNull Context context, @LayoutRes int resource, List<Goods> objects,Goodsdao goodsdao) {
super(context, resource, objects);
resouncelId=resource;
goodsList=objects;
this.goodsdao=goodsdao;
}

@NonNull
@Override
public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
final 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()+"");
viewHolder.ivdelete.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
AlertDialog.Builder builder=new AlertDialog.Builder(getContext());
builder.setTitle("你确定要删除吗？");
builder.setPositiveButton("yes", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
goodsList.remove(goods);
goodsdao.delete(goods.getId());
notifyDataSetChanged();
}
});
builder.setNegativeButton("cancel",null);
builder.show();

}
});
viewHolder.ivup.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
goods.setAmount(goods.getAmount()-1);
goodsdao.update(goods);
notifyDataSetChanged();
}
});
viewHolder.ivdown.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
goods.setAmount(goods.getAmount()+1);
goodsdao.update(goods);
notifyDataSetChanged();
}
});
return view;
}
class ViewHolder{
TextView tvId;
TextView tvname;
TextView tvamount;
ImageView ivup;
ImageView ivdown;
ImageView ivdelete;
}
}