商品展示案例ShopShowDemo

在layout文件下建立activity_main.xml主文件和item.xml项目文件。activity_main：<?xml version="1.0"encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
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"
tools:context="com.example.administrator.shopshowdemo.MainActivity">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<EditText
android:id="@+id/etName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:hint="商品名称"
android:inputType="text"
android:layout_weight="1"/>
<EditText
android:id="@+id/etAmount"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:hint="商品金额"
android:inputType="number"
android:layout_weight="1"/>
<ImageView
android:id="@+id/ivAdd"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="addGoods"
android:src="@android:drawable/ic_input_add"/>
</LinearLayout>

<ListView
android:id="@+id/ivGoods"
android:layout_width="match_parent"
android:layout_height="match_parent" />

</LinearLayout>

item：

<?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"><TextViewandroid:text="1"android:layout_width="wrap_content"android:layout_height="wrap_content"android:id="@+id/tvid"android:layout_weight="1"android:textSize="20sp"/><TextViewandroid:text="商品名称"android:gravity="left"android:layout_width="wrap_content"android:layout_height="wrap_content"android:id="@+id/tvName"android:layout_weight="1"android:textSize="20sp"/><TextViewandroid:text="商品金额"android:gravity="left"android:layout_width="wrap_content"android:layout_height="wrap_content"android:id="@+id/tvAmount"android:layout_weight="2"android:textSize="20sp"/><LinearLayoutandroid:layout_width="wrap_content"android:layout_height="wrap_content"android:orientation="vertical"><ImageViewandroid:id="@+id/ivUp"android:layout_width="wrap_content"android:layout_height="wrap_content"android:src="@android:drawable/arrow_up_float"/><ImageViewandroid:id="@+id/ivDown"android:layout_width="wrap_content"android:layout_height="wrap_content"android:src="@android:drawable/arrow_down_float"/></LinearLayout><ImageViewandroid:id="@+id/ivDelete"android:layout_width="25dp"android:layout_height="25dp"android:src="@android:drawable/ic_menu_delete"/></LinearLayout>

在java文件下建立GoodsAdapter和MainActivityGoodsAdapter：

package com.example.administrator.shopshowdemo;import android.content.Context;import android.content.DialogInterface;import android.support.annotation.NonNull;import android.support.v7.app.AlertDialog;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.administrator.shopshowdemo.dao.GoodsDao;import com.example.administrator.shopshowdemo.entity.Goods;import java.util.List;/*** Created by Administrator on 2017/4/27.*/public class GoodsAdapter extends ArrayAdapter<Goods>{private int resounceId;private GoodsDao goodsDao;private List<Goods> goodsList;public GoodsAdapter(Context context, int resource, List<Goods> objects,GoodsDao goodsDao) {super(context, resource, objects);resounceId=resource;goodsList=objects;this.goodsDao=goodsDao;}@NonNull@Overridepublic View getView(int position, View convertView, 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.[b]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.tvId.setText(goods.getAmount()+"");viewHolder.ivDelete.setOnClickListener(new View.OnClickListener(){@Overridepublic 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() {@Overridepublic void onClick(DialogInterface dialogInterface, int which) {goodsList.remove(goods);goodsDao.delete(goods.getId());notifyDataSetChanged();}});builder.setNegativeButton("cancel",null);builder.show();}});viewHolder.ivUp.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {goods.setAmount(goods.getAmount()-1);goodsDao.update(goods);notifyDataSetChanged();}});viewHolder.ivDown.setOnClickListener(new View.OnClickListener() {@Overridepublic 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;}}

MainAcivity：

package com.example.administrator.shopshowdemo;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.text.TextUtils;import android.view.View;import android.widget.EditText;import android.widget.ListView;import android.widget.Toast;import com.example.administrator.shopshowdemo.dao.GoodsDao;import com.example.administrator.shopshowdemo.entity.Goods;import java.util.List;public class MainActivity extends AppCompatActivity {private EditText etName;private EditText etAmount;private ListView IvGoods;private GoodsAdapter goodsAdapter;private GoodsDao goodsDao;private List<Goods> goodsList;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);etName=(EditText)findViewById(R.id.etName);etAmount=(EditText)findViewById(R.id.etAmount);IvGoods=(ListView) findViewById(R.id.ivGoods);goodsDao=new GoodsDao(this);goodsList=goodsDao.queryAll();goodsAdapter=new GoodsAdapter(this,R.layout.item,goodsList,goodsDao);IvGoods.setAdapter(goodsAdapter);}public void addGoods(View view){String name=etName.getText().toString();String amount=etAmount.getText().toString();if (TextUtils.isEmpty(name)||TextUtils.isEmpty(amount))return;Goods goods=new Goods(name,Integer.parseInt(amount));goodsDao.add(goods);goodsList.add(goods);goodsAdapter.notifyDataSetChanged();etName.setText("");etAmount.setText("");Toast.makeText(this,"添加成功",Toast.LENGTH_LONG).show();}}

在java文件下建立dao，db，entity包；在dao包下建立GoodsDao类，在db包下建立DBHelper类，在entity下建立Goods类。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;}}

DBHelper：

package com.example.administrator.shopshowdemo.db;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteOpenHelper;/*** Created by Administrator on 2017/4/27.*/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);}@Overridepublic void onCreate(SQLiteDatabase db) {db.execSQL(CREATE_GOODS);}@Overridepublic void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {}}

Goods：

package com.example.administrator.shopshowdemo.entity;/*** Created by Administrator on 2017/4/27.*/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;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 String getName() {return name;}public void setName(String name) {this.name = name;}public Integer getAmount() {return amount;}public void setAmount(Integer amount) {this.amount = amount;}@Overridepublic String toString() {return "Goods{" +"id=" + id +", name='" + name + '\'' +", amount=" + amount +'}';}}