一、 创建手机界面布局

创建一个activity_main.xml文件代码如下：

xmlns:tools="http://schemas.android.com/tools"

android:id="@+id/activity_main"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:paddingBottom="@dimen/activity_vertical_margin"

android:paddingLeft="@dimen/activity_horizontal_margin"

android:paddingRight="@dimen/activity_horizontal_margin"

android:paddingTop="@dimen/activity_vertical_margin"

tools:context="com.example.bz0209.shopshowdemo.activity_main"

android:orientation="vertical">

android:layout_width="match_parent"

android:layout_height="wrap_content">

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"

/>

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"

/>

android:id="@+id/ivAdd"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:onClick="addGoods"

android:inputType="text"

android:src="@android:drawable/ic_input_add"

/>

android:id="@+id/lvGoods"

android:layout_width="match_parent"

android:layout_height="match_parent">

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：

android:layout_width="match_parent"

android:layout_height="match_parent">

android:text="1"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:id="@+id/tvId"

android:textSize="20sp"

android:layout_weight="2"

/>

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"

/>

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"

/>

android:id="@+id/ivUP"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:src="@android:drawable/arrow_up_float"

/>

android:id="@+id/ivDown"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:src="@android:drawable/arrow_down_float"

/>

android:id="@+id/ivDelete"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:src="@android:drawable/arrow_down_float"

/>

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：

(2)最后的运行结果图：

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。