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最新推荐文章于 2023-10-19 15:03:50 发布

qq_37738218

最新推荐文章于 2023-10-19 15:03:50 发布

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本文链接：https://blog.youkuaiyun.com/qq_37738218/article/details/71435615

版权

商品展示用户交互界面：

<?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: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.showshopdemo.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/addIV"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@android:drawable/ic_input_add"
            />
        <ListView
            android:id="@+id/accountLV"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_below="@+id/addLL">
        </ListView>
    </LinearLayout>>


</LinearLayout>

添加了三个TextView用于展示数据库中的某条数据的id、商品名称、金额：

![这里写图片描述](https://img-blog.youkuaiyun.com/20170508210800571?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvcXFfMzc3MzgyMTg=/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/SouthEast)

<TextView
    android:id="@+id/tvId"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_weight="1"
    android:text="1"
    android:textColor="#000000"
    android:textSize="20sp" />

<TextView
    android:id="@+id/tvName"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_weight="2"
    android:text="商品名称"
    android:textColor="#000000"
    android:textSize="20sp" />

<TextView
    android:id="@+id/tvAmount"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_weight="2"
    android:text="金额"
    android:textColor="#000000"
    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="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="2dp"
        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:id="@+id/ivDelete"
    android:layout_width="25dp"
    android:layout_height="25dp"
    android:src="@android:drawable/ic_menu_delete" />

![这里写图片描述](https://img-blog.youkuaiyun.com/20170508210404487?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvcXFfMzc3MzgyMTg=/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/SouthEast)

![这里写图片描述](https://img-blog.youkuaiyun.com/20170508210610615?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvcXFfMzc3MzgyMTg=/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/SouthEast)
创建数据库：

DBHelper.java:

package com.example.bz0209.showshopdemo.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 sqLiteDatabase, int i, int i1) {

}

}


界面显示如：
![这里写图片描述](https://img-blog.youkuaiyun.com/20170508210655211?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvcXFfMzc3MzgyMTg=/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/SouthEast)

GoodsAdapter.java:

package com.example.bz0209.showshopdemo.entity;

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.showshopdemo.R;

import java.util.List;

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

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.tvName= (TextView) view.findViewById(R.id.tvName);
        viewHolder.tvId= (TextView) view.findViewById(R.id.tvId);
        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()+"");


    return view;
}
class ViewHolder{
    TextView tvId;
    TextView tvName;
    TextView tvAmount;
    ImageView ivUp;
    ImageView ivDown;
    ImageView ivDelete;
}

}

package com.example.bz0209.showshopdemo;

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.showshopdemo.dao.GoodsDao;
import com.example.bz0209.showshopdemo.entity.Goods;
import com.example.bz0209.showshopdemo.entity.GoodsAdapter;

import java.util.List;

public class MainActivity extends AppCompatActivity {
private EditText etName;
private EditText etAmount;
private ListView lvGoods;
private GoodsAdapter goodsAdapter;
private GoodsDao goodsDao;
private List goodsList;

@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);

}

}

![这里写图片描述](https://img-blog.youkuaiyun.com/20170508210850821?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvcXFfMzc3MzgyMTg=/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/SouthEast)

package com.example.bz0209.showshopdemo.dao;

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

import com.example.bz0209.showshopdemo.db.DBHelper;
import com.example.bz0209.showshopdemo.entity.Goods;

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

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();
}
}

package com.example.bz0209.showshopdemo.entity;

/**
* Created by Administrator 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;
    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;
}

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

}

“`