关于商品展示

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/k_korol/article/details/70887403

效果图

添加数据之后

布局文件

activity_main.xml

<?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"
    android:layout_margin="8dp"
    tools:context="cn.edu.bzu.product.MainActivity">

    <LinearLayout
        android:id="@+id/addLL"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
        <EditText
            android:id="@+id/nameET"
            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/balanceET"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:hint="金额"
            android:inputType="number"/>
        <ImageView
            android:onClick="add"
            android:id="@+id/addTV"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@android:drawable/ic_input_add"/>

    </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="wrap_content"
    android:orientation="horizontal"
    android:padding="10dp">
    <TextView
        android:id="@+id/idTV"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:text="13"
        android:textColor="#000000"
        android:textSize="20sp"/>
    <TextView
        android:id="@+id/nameTV"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="2"
        android:singleLine="true"
        android:text="PQ"
        android:textColor="#000000"
        android:textSize="20sp"/>
    <TextView
        android:id="@+id/balanceTV"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="2"
        android:text="12345"
        android:textColor="#000000"
        android:textSize="20sp"/>
    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical">
        <ImageView
            android:id="@+id/upTV"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@android:drawable/arrow_up_float"/>

        <ImageView
            android:id="@+id/downTV"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@android:drawable/arrow_down_float"/>

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

</LinearLayout>

Account.class

package cn.edu.bzu.product.bean;

/**
 * Created by Administrator on 2017/4/13.
 */

public class Account {
    private long id;
    private String name;
    private Integer balance;

    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 getBalance() {
        return balance;
    }

    public void setBalance(Integer balance) {
        this.balance = balance;
    }
    public Account(long id,String name,Integer balance){
        super();
        this.id=id;
        this.name=name;
        this.balance=balance;
    }
    public Account(String name,Integer balance){
        super();
        this.name=name;
        this.balance=balance;
    }

    @Override
    public String toString() {
        return "[序号:"+id+",商品名称:"+name+",余额:"+balance;
    }
}

AccountDao.class

package cn.edu.bzu.product.dao;

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

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

import cn.edu.bzu.product.bean.Account;

/**
 * Created by Administrator on 2017/4/13.
 */

public class AccountDao {
    private MyHelper helper;
    public AccountDao(Context context){
        helper=new MyHelper(context);
    }
    public void insert(Account account){
        SQLiteDatabase db=helper.getWritableDatabase();
        ContentValues values=new ContentValues();
        values.put("name",account.getName());
        values.put("balance",account.getBalance());
        long id=db.insert("account",null,values);
        account.setId(id);
        db.close();
    }
    public int delete(long id){
        SQLiteDatabase db=helper.getWritableDatabase();
        int count=db.delete("account","_id=?",new String[]{id+""});
        db.close();
        return count;
    }
    public int update(Account account){
        SQLiteDatabase db=helper.getWritableDatabase();
        ContentValues values=new ContentValues();
        values.put("name",account.getName());
        values.put("balance",account.getBalance());
        int count=db.update("account",values,"_id=?",new String[]{account.getId()+""});
        db.close();
        return count;
    }
    public List<Account> queryAll(){
        SQLiteDatabase db=helper.getWritableDatabase();
        Cursor c=db.query("account",null,null,null,null,null,"balance DESC");
        List<Account> list=new ArrayList<Account>();
        while (c.moveToNext()){
            long id=c.getLong(c.getColumnIndex("_id"));
            String name=c.getString(1);
            int balance=c.getInt(2);
            list.add(new Account(id,name,balance));
        }
        c.close();
        db.close();
        return list;
    }
}

MyHelper.class

package cn.edu.bzu.product.dao;

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


/**
 * Created by Administrator on 2017/4/13.
 */

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");
    }
}

MainActivity.class

package cn.edu.bzu.product;

import android.content.DialogInterface;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import java.util.List;

import cn.edu.bzu.product.bean.Account;
import cn.edu.bzu.product.dao.AccountDao;

public class MainActivity extends AppCompatActivity {
    private List<Account> list;
    private AccountDao dao;
    private EditText nameET;
    private EditText balanceET;
    private MyAdapter adapter;
    private ListView accountLV;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
        dao=new AccountDao(this);
        list=dao.queryAll();
        adapter=new MyAdapter();
        accountLV.setAdapter(adapter);

    }

    private void initView() {
        accountLV=(ListView) findViewById(R.id.accountLV);
        nameET=(EditText) findViewById(R.id.nameET);
        balanceET=(EditText) findViewById(R.id.balanceET);
        accountLV.setOnItemClickListener(new MyOnItemClickListener());
    }
    public void add(View v){
        String name=nameET.getText().toString().trim();
        String balance=balanceET.getText().toString().trim();
        Account a=new Account(name,balance.equals("")?0:Integer.parseInt(balance));
        dao.insert(a);
        list.add(a);
        adapter.notifyDataSetChanged();
        accountLV.setSelection(accountLV.getCount()-1);
        nameET.setText("");
        balanceET.setText("");
        Toast.makeText(this,"添加成功",Toast.LENGTH_SHORT).show();
    }
    private class MyAdapter extends BaseAdapter{
        @Override
        public int getCount() {
            return list.size();
        }

        @Override
        public Object getItem(int position) {
            return list.get(position);
        }

        @Override
        public long getItemId(int position) {
            return position;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            View item=convertView!=null?convertView:View.inflate(getApplicationContext(),R.layout.item,null);
            TextView idTV=(TextView) item.findViewById(R.id.idTV);
            TextView nameTV= (TextView) item.findViewById(R.id.nameTV);
            TextView balanceTV=(TextView) item.findViewById(R.id.balanceTV);
            final Account a=list.get(position);
            idTV.setText(a.getId()+"");
            nameTV.setText(a.getName());
            balanceTV.setText(a.getBalance()+"");
            ImageView upTV=(ImageView) item.findViewById(R.id.upTV);
            ImageView downTV=(ImageView) item.findViewById(R.id.downTV);
            ImageView deleteTV=(ImageView) item.findViewById(R.id.deleteTV);
            upTV.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    a.setBalance(a.getBalance()+1);
                    notifyDataSetChanged();
                    dao.update(a);
                }
            });
            downTV.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    a.setBalance(a.getBalance()-1);
                    notifyDataSetChanged();
                    dao.update(a);
                }
            });
            deleteTV.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    DialogInterface.OnClickListener listener=new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialogInterface, int i) {
                            list.remove(a);
                            dao.delete(a.getId());
                            notifyDataSetChanged();
                        }
                    };
                    AlertDialog.Builder buileder =new AlertDialog.Builder(MainActivity.this);
                    buileder.setTitle("确定要删除吗？");
                    buileder.setPositiveButton("确定",listener);
                    buileder.setNegativeButton("取消",null);
                    buileder.show();
                }
            });
            return item;
        }
    }
    private class MyOnItemClickListener implements AdapterView.OnItemClickListener{
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
            Account a=(Account) adapterView.getItemAtPosition(i);
            Toast.makeText(getApplicationContext(),a.toString(),Toast.LENGTH_SHORT).show();
        }
    }
}